FOUS30 KWBC 010645
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
145 AM EST Sun Mar 1 2026

Day 1
Valid 12Z Sun Mar 01 2026 - 12Z Mon Mar 02 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Cook


Day 2
Valid 12Z Mon Mar 02 2026 - 12Z Tue Mar 03 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Cook


Day 3
Valid 12Z Tue Mar 03 2026 - 12Z Wed Mar 04 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
MISSOURI, ILLINOIS, AND INDIANA...

A mid/upper wave initially over the Intermountain West/Central
Rockies will make eastward progress throughout the forecast period,
fostering surface cyclogenesis in the general vicinity of southern Kansas/Oklahoma. As this occurs, an expansive warm/moist advection
regime will become established across much of the Mississippi/Lower
Ohio River Valleys and Missouri Ozarks. A warm front will become
established in the general vicinity of the I-70 corridor across
central Illinois, providing a focus for areas of repeating
rainfall/convection supported by westerly steering flow aloft
parallel to the front. A few areas of 1-2 inches of rainfall are
possible. Main uncertainties/mitigating factors for excessive
rainfall involve 1) extremely dry antecedent conditions in most
areas, with soil moistures quite low for the time of year, 2)
uncertainly in location of the warm front and associated precip
axis (GFS north, EURO/UKMET farther south), and lack of surface-
based instability for deep convection. Marginal Risk area has been
maintained for this outlook from the prior D4 ERO, though uncertainties/mitigating factors have led to a substantial
shrinking of this risk from the prior forecast.

Cook
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 020812
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
312 AM EST Mon Mar 2 2026

Day 1
Valid 12Z Mon Mar 02 2026 - 12Z Tue Mar 03 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Cook


Day 2
Valid 12Z Tue Mar 03 2026 - 12Z Wed Mar 04 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MIDWEST AND OHIO VALLEY...

Models remain consistent in developing an axis of precipitation
along a warm front extending generally from southeastern Kansas
eastward along the Ohio River Valley. Models do vary, however, with
specific location of this front. Areas of 0.5-1.5 inch of rainfall
are expected within the Marginal Risk area, with a few spots
exceeding 2 inches possible. The nature of the front (parallel to
westerly steering flow aloft) will enable some training, and if
deeper convection can organize (as suggested by the ECMWF), locally
higher amounts may be observed. Antecedent dry conditions continue
to remain a limiting factor for flash flood potential as much of
the region has very high soils and is in drought. A few issues with
runoff are possible - with potetial maximized in the Marginal Risk
area during the 00Z-12Z Wed 4 Mar forecast period.

Cook


Day 3
Valid 12Z Wed Mar 04 2026 - 12Z Thu Mar 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM NORTH TEXAS NORTHEASTWARD INTO THE MID-MISSISSIPPI VALLEY...

Low-level warm advection will intensify across the southern Plains
and Ozarks as a mid-level wave approaches the central Plains
(while taking a neutral tilt) throughout the forecast period. As
this occurs, low-level cyclogenesis and strengthing of a surface
cold front over eastern Kansas/Oklahoma will foster areas of deep
convection that should migrate northeastward across the Marginal
Risk area. Models suggest that initial convection should
materialize as scattered clusters within the broader warm conveyor
from north Texas into Missouri, with a gradual congealing into a forward-propagating complex late in the period. Specific spatial
details regarding this evolution are unclear, but areas of 2-3.5
inches of rainfall appear to be likely where cells can repeat/merge
on a localized basis. Soil moistures/antecedent conditions are
quite dry, however, casting some doubt on the runoff potential
across the region. Nevertheless, varied/locally sensitive terrain
(especially in the Ozarks) and heavy rainfall suggests at least
isolated runoff issues can be expected. Depending of specific
convective evolution, a Slight Risk may be needed in portions of
Missouri in later outlooks.

Farther northeast (into Indiana and Ohio), the D3 forecast period
will mark a second consecutive day of potential 1 inch rainfall
along/near a surface warm front across the region. Overall
instability profiles remain marginal, but with wetting soils, a
gradual increase in excessive runoff potential may necessitate a
Marginal Risk area in later outlooks.

Cook
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 030830
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
330 AM EST Tue Mar 3 2026

Day 1
Valid 12Z Tue Mar 03 2026 - 12Z Wed Mar 04 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MIDWEST AND OHIO VALLEY...

Models have solidified their agreement in an axis of 1-2 inch
rainfall totals generally from northeastern Missouri eastward
through southern Ohio. These totals will coincide with an east-west
oriented front across the region, with point forecast soundings
suggesting fairly fast cellular motions and minimal surface-based
instability. The main contributor for flash flood potential with
this axis is repeating/training rainfall, though dry antecedent
conditions remain a mitigating factor for a larger-scale flash
flood risk. One exception to this is West Virginia - soil
moistures are relatively wet there compared to points west.
Rainfall totals may be somewhat lighter there too though (0.5-1.5
inches), also keeping any flash flood potential isolated.

Cook


Day 2 Valid 12Z Wed Mar 04 2026 - 12Z Thu Mar 05 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM NORTH TEXAS NORTHEASTWARD INTO THE OHIO VALLEY...

Minimal changes are made to the inherited outlook. At the mid-
levels, an approaching trough will reach the central Plains during
the forecast period. As this occurs, strengthening, confluent low-
level flow from north Texas into the Missouri Ozarks will aid in
moisture transport and eventually deep convective development
especially during the afternoon/evening hours. That convective
development will migrate from southwest to northeast within the
aforementioned warm conveyor, with areas of training/repeating
possible along with local rainfall totals exceeding 3 inches
through 12Z Thursday. The collocation of these rainfall totals with varied/sensitive terrain over southwest Missouri/northwest Arkansas
suggests that higher probabilities and a Slight Risk may need to be
introduced at some point. Lingering concerns regarding antecedent
conditions (very dry soils) and eventual convective evolution
(models exhibiting a slight westward trend over the past 24 hours)
gives pause on introducing an upgrade at this time, however.
Current trends suggest that the greatest risk of flash flooding
will exist along an axis from Fayetteville, AR to Rolla, MO,
though this axis may change between now and Wednesday
afternoon/evening.

Farther northeast, areas of rain (approaching 1-1.5 inch total in
spots) will develop from southern Illinois eastward through West
Virginia in similar locations that are expected to receive 1-2
inches of rain during the D1 forecast period (Tuesday into Tuesday
night). Soils should continue to moisten during this period, with
isolated instances of flash flooding remaining possible.

Cook


Day 3 Valid 12Z Thu Mar 05 2026 - 12Z Fri Mar 06 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Models are in general agreement that longwave trough will deepen
across the Intermountain West, spreading southwesterly flow aloft
over a large part of the Great Plains. Meanwhile, low-level
moisture advection will aid in an airmass characterized by 1.25-1.5
inch PW values along and just east of a dryline generally extending
from near Goodland to near Amarillo. Models depict scattered
convection developing amid supercellular wind fields Thursday
afternoon, with a mix of cells and linear segments possible along
parts of the dryline. Local cell mergers may result in a couple
spots of 2-3 inch rainfall totals in this regime, though the
overall footprint of heavier rainfall should be too small to even
delineate a Marginal Risk area at this timeframe. Antecedent dry conditions/drought are also mitigating factors for flash flood
potential. This scenario will need to be monitored for any
potential increase in convective coverage that might necessitate a
Marginal in later outlooks.

Cook
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 040802
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
302 AM EST Wed Mar 4 2026

Day 1
Valid 12Z Wed Mar 04 2026 - 12Z Thu Mar 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE OZARKS...

Upper air pattern from the Central Rockies to the Ohio Valley
remains relatively amplified with a deep shortwave trough analyzed
across CO, slowly ejecting out into the Front Range this evening.
At the surface, a weak surface reflection remains parked over
southwest MO with a trailing cold front analyzed back through OK
into the TX Panhandle. Expected evolution of the entire pattern
will yield a slow-moving cold frontal approach across the Southern
Plains with sights downstream on the Mid and Lower-Mississippi
Valley area as we move into the front half of D1. Defined confluent
flow within a persistent axis of diffluence across E TX into the
Mississippi Valley will allow for a continuation of convective
pulses to develop and propagate northeast along the trailing front
with a multi-wave complex of thunderstorms expected to impact areas
from north TX up through eastern OK, northwest AR, eventually
through southern MO. Relative instability remains modest, at best
ahead of the trough axis with general theta_E favored environment
located along and south of the cold front bisecting the above areas.

PWAT anomalies between 2-3 deviations above normal will enhance
heavy rain prospects within any cell maturation with a broad axis
of at least light to moderate rain likely ongoing from later this
morning, carrying through the afternoon. A brief period of
generally lighter rainfall is anticipated prior to sunset, however,
expectation is for round two to develop with the advent of the
budding 850mb LLJ positioned southeast of the surface low as it
finally begins to migrate east-northeast from southern MO. The
multi-wave precip forecast will allow for priming of the dry soils
currently in place across the Ozarks with forecasts of 3-5" totals
being projected via the latest CAMs in areas hit multiple times by
the waves. Widespread 1-2" are forecast surrounding with the
"bullseye" of precip aligned from far eastern OK up through
northwest AR into southern MO with the heaviest likely occurring
over the rugged terrain of the Ozarks between AR and MO. 00z HREF
neighborhood probs for >3" of rainfall are running between 40-80%
over the above zone with low-end probs (15-30%) for >5" across
southern MO, south of I-44. This seems to have a good consensus
when assessing the more conservative EAS probs with modest
probabilities (35-60%) for at least 2" running just east of
Springfield to just west of I-55.

Despite those drier antecedent conditions, longevity in the threat
for heavy rainfall given the dual-wave structure of the precip
field will allow for isolated to scattered flash flood prospects.
In coordination with the Springfield, MO and Little Rock, AR WFO's,
a SLGT risk ERO was introduced in the latest update encompassing
through areas from far eastern OK up through northwest AR into southern MO.

Kleebauer


Day 2
Valid 12Z Thu Mar 05 2026 - 12Z Fri Mar 06 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Kleebauer


Day 3
Valid 12Z Fri Mar 06 2026 - 12Z Sat Mar 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE SOUTHERN PLAINS INTO THE MID-MISSISSIPPI VALLEY...

Pattern across the western half of the CONUS becomes highly
amplified as a potent upper trough migrate east off the Pacific
with sights downstream on the Rockies and eventually the Southern
and Central Plains as we move into the end of the week and beyond.
There's still some discrepancy on exactly where the heaviest precip
will arise as the meridional component of the upper levels will
certainly open the door for any areas across the Southern Plains
to Mississippi Valley to experience scattered to widespread heavy
rainfall prospects with the Southern Plains and Lower Mississippi
Valley likely the most susceptible to more prolific convective
modes. Given the positioning of central and east TX up through the
ArkLaTex within a persistent diffluent upper level regime and the
best instability maximum located within the fresh Gulf moisture
advection pattern thanks to prevailing south to southeast flow,
there is a growing concern for heavy rainfall to initiate and move
overhead in these general areas. This threat extends further
northeast into the Mid-Mississippi Valley as noted via precip
footprint off the latest ensemble blends, including the NBM and
bias-corrected ensemble. Deterministic is all over the place with
regards to specifics, however, and with the period outside CAMs
windows, it's a bit too early for a SLGT risk proposition with
still some time to discern details as we move closer. The MRGL risk
inherited was maintained, but expectation for an upgrade is
relatively high given the nature of the setup.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 041600
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Wed Mar 4 2026

Day 1
Valid 16Z Wed Mar 04 2026 - 12Z Thu Mar 05 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE OZARKS AND THE OHIO VALLEY...

16Z Update...

Changes for this update include south and eastward expansions of
the Slight Risk over the Ozarks to account for a generally heavier
convective footprint over eastern OK up across much of northwest AR
and southern MO. Multiple rounds of heavy showers and thunderstorms
across these areas over the next 12 to 18 hours will likely prime
the otherwise dry soils sufficiently to increase the threat for
runoff problems and some isolated to potentially scattered areas of
flash flooding. Increasing CAPE and rather anomalous PWs pooling up
along a strong frontal zone working in tandem with ejecting
shortwave energy should favor relatively organized convective
clusters. The activity later today and tonight will be capable of
locally training over the same area given favorable deep layer
steering flow aligning with the frontal placement. Still thinking
locally 3 to 5 inch rainfall totals which is in good agreement with
the 12Z HREF probabilistic output.

An area to closely watch for this evening/overnight will also be
parts of central and northern TX (including the DFW metropolitan
area) as there are several 12Z CAM solutions (ARW/ARW2, HRRR and
RRFS) showing relatively slow-moving and rather discreet pockets of
convection with high rainfall rates in close proximity to the cold
front settling down across this region. Antecedent conditions are
dry, but the high rainfall rates, and slower cell-motions may
foster locally several inches of rain which certainly would drive a
threat for at least isolated flash flooding concerns and especially
if they manifest into a more urbanized environment. As such, the
Marginal Risk has been broadened down into these ares of central
and northern TX.

A Slight Risk has been introduced across portions of the OH Valley
including southern IN, southern OH, far northern WV and a small
part of northwest WV where locally a combination of additional
rounds of heavy rain (1 to 2+ inches) coupled with wet antecedent
conditions from recent rainfall will foster greater runoff
concerns. Already many areas this morning have lingering runoff
problems from last night's 1 to 3 inches of rain that fell, so the
additional rains will strongly contribute to elevated streamflows
and runoff concerns.

Orrison

Previous discussion...

Upper air pattern from the Central Rockies to the Ohio Valley
remains relatively amplified with a deep shortwave trough analyzed
across CO, slowly ejecting out into the Front Range this evening.
At the surface, a weak surface reflection remains parked over
southwest MO with a trailing cold front analyzed back through OK
into the TX Panhandle. Expected evolution of the entire pattern
will yield a slow-moving cold frontal approach across the Southern
Plains with sights downstream on the Mid and Lower-Mississippi
Valley area as we move into the front half of D1. Defined confluent
flow within a persistent axis of diffluence across E TX into the
Mississippi Valley will allow for a continuation of convective
pulses to develop and propagate northeast along the trailing front
with a multi-wave complex of thunderstorms expected to impact areas
from north TX up through eastern OK, northwest AR, eventually
through southern MO. Relative instability remains modest, at best
ahead of the trough axis with general theta_E favored environment
located along and south of the cold front bisecting the above areas.

PWAT anomalies between 2-3 deviations above normal will enhance
heavy rain prospects within any cell maturation with a broad axis
of at least light to moderate rain likely ongoing from later this
morning, carrying through the afternoon. A brief period of
generally lighter rainfall is anticipated prior to sunset, however,
expectation is for round two to develop with the advent of the
budding 850mb LLJ positioned southeast of the surface low as it
finally begins to migrate east-northeast from southern MO. The
multi-wave precip forecast will allow for priming of the dry soils
currently in place across the Ozarks with forecasts of 3-5" totals
being projected via the latest CAMs in areas hit multiple times by
the waves. Widespread 1-2" are forecast surrounding with the
"bullseye" of precip aligned from far eastern OK up through
northwest AR into southern MO with the heaviest likely occurring
over the rugged terrain of the Ozarks between AR and MO. 00z HREF
neighborhood probs for >3" of rainfall are running between 40-80%
over the above zone with low-end probs (15-30%) for >5" across
southern MO, south of I-44. This seems to have a good consensus
when assessing the more conservative EAS probs with modest
probabilities (35-60%) for at least 2" running just east of
Springfield to just west of I-55.

Despite those drier antecedent conditions, longevity in the threat
for heavy rainfall given the dual-wave structure of the precip
field will allow for isolated to scattered flash flood prospects.
In coordination with the Springfield, MO and Little Rock, AR WFO's,
a SLGT risk ERO was introduced in the latest update encompassing
through areas from far eastern OK up through northwest AR into southern MO.

Kleebauer


Day 2
Valid 12Z Thu Mar 05 2026 - 12Z Fri Mar 06 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Kleebauer


Day 3
Valid 12Z Fri Mar 06 2026 - 12Z Sat Mar 07 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE SOUTHERN PLAINS INTO THE MID-MISSISSIPPI VALLEY...

Pattern across the western half of the CONUS becomes highly
amplified as a potent upper trough migrate east off the Pacific
with sights downstream on the Rockies and eventually the Southern
and Central Plains as we move into the end of the week and beyond.
There's still some discrepancy on exactly where the heaviest precip
will arise as the meridional component of the upper levels will
certainly open the door for any areas across the Southern Plains
to Mississippi Valley to experience scattered to widespread heavy
rainfall prospects with the Southern Plains and Lower Mississippi
Valley likely the most susceptible to more prolific convective
modes. Given the positioning of central and east TX up through the
ArkLaTex within a persistent diffluent upper level regime and the
best instability maximum located within the fresh Gulf moisture
advection pattern thanks to prevailing south to southeast flow,
there is a growing concern for heavy rainfall to initiate and move
overhead in these general areas. This threat extends further
northeast into the Mid-Mississippi Valley as noted via precip
footprint off the latest ensemble blends, including the NBM and
bias-corrected ensemble. Deterministic is all over the place with
regards to specifics, however, and with the period outside CAMs
windows, it's a bit too early for a SLGT risk proposition with
still some time to discern details as we move closer. The MRGL risk
inherited was maintained, but expectation for an upgrade is
relatively high given the nature of the setup.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 051246
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
746 AM EST Thu Mar 5 2026

Day 1
Valid 1245Z Thu Mar 05 2026 - 12Z Fri Mar 06 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE OHIO RIVER VALLEY AND THE SOUTHERN PLAINS...

13z Update: We sent a quick update to expand the Marginal risk
into southeast OK. Ongoing convection is exhibiting some
training/backbuilding characteristics this morning. This activity
is not being handled well by the high res guidance, but with
recent cloud top cooling, upstream instability, and wind fields
favorable for backbuilding...it seems probable that this convection
will persist for at least a few more hours resulting in a
localized flash flood risk.

Chenard

...Ohio River Valley...

Potent mid-level shortwave propagation over the Central Plains will
continue over the course of this evening into D1 with a core axis
of diffluence centered over the Mid-Mississippi and Ohio Valleys in
the beginning of the period. Multiple vorticity maxima will eject
northeast out of the Ozarks area with a stationary front at the
surface bisecting areas from North TX up through the Ohio River
Basin. Moisture transport with the setup is pretty much aligned
parallel to the mean flow leading to more organized convective
clusters propagating along the front, disseminating some relatively
solid QPF output from Dallas up through the north-central Ohio
Valley. Models are in agreement on the shortwave propagation out of
the Ozarks this evening to migrate northeast with an eventual
secondary wave of heavy precip impacting areas along the Ohio River
Basin, including as far west at the confluence of the
Ohio/Mississippi Rivers and points east-northeast along the Ohio
River bordering KY/IL/IN/OH. Multi-day rainfall output will place
areas of IN/OH within another period of rainfall which is already
causing issues for places south of I-70 in both states.

Heaviest rainfall is progged to occur to the southwest with the
signal via the latest 00z HREF really emphasizing the corridor at
the confluence of the Mississippi/Ohio rivers up through the
KY/IL/IN border, much of which falling between the 12-21z time
frame today. Neighborhood probs for >2" are between 40-60% over the aforementioned area with a few deterministic CAMs producing
between 3-5" over the time frame. Considering the nature of the
overlap of heavy rainfall occurring tonight and then again in the
morning/early afternoon, there was enough of a signal to add a MRGL
risk for the region in question.

...Southern Plains...

Stationary boundary across TX will lift north during the morning
and afternoon period today with a quick theta_E advection regime
taking shape across much of the Southern Plains. Upstream trough
axis pushing through the west will help to re-amplify the flow
across the South-Central U.S. with a low pressure center forming
across the Front Range with a trailing dryline maturing across the
western TX Panhandle up down through southwest TX. Increasing
ascent within the diffluent axis downstream of the longwave trough, ample instability located downstream of the dryline, and increased bulk
shear profiles will promote a favorable instance of convective
development and maintenance of present updrafts. NAEFS PWAT
percentile forecast is pushing the 99th percentile via
climatological norms across the region from the Red River, north
through the western half of OK into southern KS by late this
afternoon and beyond. This is a testament to the anticipated
proliferation of convective cells within the favorable environment,
each of which will be capable of heavy rain cores with hourly rates
pushing 2-3"/hr at peak intensity as noted via some of the latest
CAMs. Despite this area signifying higher FFG's due to a dearth of precipitation lately, this setup is conducive for stronger
convection as noted via the SPC's Slight Risk outlook for severe
weather focused within that area downstream of the dryline. A low-
end scenario for flash flooding is the forecast for this particular
domain just given the deep moist favorability, as well as the
organized convective pattern likely to exhibit some pretty hefty
rainfall in localized areas as the cells migrate to the east and
northeast. A MRGL risk was added for the region encompassing North
TX up through western OK into southern KS.

Kleebauer


Day 2
Valid 12Z Fri Mar 06 2026 - 12Z Sat Mar 07 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE LOWER MISSISSIPPI VALLEY, INCLUDING THE ARKLATEX...

...ArkLaTex to Lower Mississippi Valley...

Highly amplified pattern across the western CONUS will shift
eastward over the course of the end of the week and weekend leaving
a broad axis of convective development downstream over the Southern
Plains up into the Midwest to the Mississippi Valley. Guidance is
beginning to come into agreement on the area located from northeast
TX up through the ArkLaTex to the western half of the Lower
Mississippi Valley a focal point for heavy, organized convection
capable of flash flood concerns. Instability and moisture presence
will not be limited in this synoptic evolution with a robust
meridional push of favorable theta_E's thanks to a funneling of
Gulf moisture poleward downstream of the mean trough. Slow-moving
cold front across the Central and Southern Plains will pick up
speed by the end of the forecast period with a defined warm sector
situated from the eastern half of TX up through the Missouri Valley
with PWAT anomalies pushing 2-3 standard deviations above normal
for the time frame. Ensemble bias corrected QPF is now pushing over
2" across the ArkLaTex with the convergence signal strongest over
the three-state region as the nocturnal LLJ is forecast to nose
into the area promoting the most favorable axis for organized
convection and eventual cell mergers after sunset. CAMs are still a
bit out of range for this threat, however the signals are already
creeping into the end of their temporal ranges with some already
showing 2" of precip with more to come across this area of the
CONUS. This setup is bordering textbook for these kinds of
convective evolutions and impacts which lends enough favor to
upgrade the previous MRGL risk inheritance to a SLGT risk for the
highlighted zones. This setup is one to monitor as short term
convective trends could adjust the risk positioning further west
thanks to the overall amplified evolution.

...Midwest...

Amplified pattern to the west will impact the north-central CONUS,
as well as the wavy stationary front over the Central Plains and
Mississippi Valley will lift rapidly to the north as a warm front,
allowing for a steady increase in regional buoyancy and deep
moisture presence. Upper pattern out west will evolve into a setup
that splits the main shortwave in two, ejecting a piece of the
mid-level vortmax rapidly to the northeast leading to lee
cyclogenesis over western KS, lifting to the northeast. The
combination of increasing shear and ascent at both the surface and
aloft will allow for a heavy convective conglomeration to
materialize over the Missouri River Valley and points east with
sights on the Midwest with a centroid over IA/Southern WI/Northwest
IL. The good news is the setup is progged to be moving quickly, so
any impacts will be short but locally intense. Localized flash
flood prospects are forecast for the above areas as the convective
pattern will promote rates between 1-2"/hr at peak intensity,
enough to approach, and/or eclipse the lower end of the FFG
thresholds in place. The previous MRGL risk was maintained as a
result with only minor adjustments made to the east and northeast
fringes to the risk area.

Kleebauer


Day 3
Valid 12Z Sat Mar 07 2026 - 12Z Sun Mar 08 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF
THE SOUTHERN PLAINS UP THROUGH THE LOWER MISSISSIPPI VALLEY...

As the longwave pattern across the western half of the CONUS
materializes and the surface reflections make their headway to the east/northeast, the cold front trailing the primary low moving
into the Great Lakes will continue its progress through the
Southern Plains into the Mississippi Valley losing latitude as it
propagates to the southeast. As the low moves further away and the
setup begins to lose upper level favor, the cold front is expected
to "fan out" as it approaches the Gulf coast leading to convective
alignment along and just ahead of the front to slow its progression
with the mean flow becoming a bit more parallel to the frontal
alignment. Moisture and instability will be plentiful with the
environment primed from a rich Gulf moisture advection regime that
will take place the previous 48 hrs. Models are in agreement on an
axis of heavy QPF located from TX to points northeast over portions
of AR/LA/western TN/northwest MS. There will likely be an area of
3+" of precip as noted via modest NBM probs for the threshold
(10-30%) and 90th percentile QPF output pushing over 3" for part of
east TX into northern LA with widespread 2+" outputs surrounding.

This setup is notorious for conditions to prime and favor areas
further southeast just due to the better instability maxima and
deeper moisture layer ahead of the front naturally positioned
closer to the Gulf coast. Pending forward propagation speed of the
cold front, heavy rainfall could very well make a push towards the
I-10 corridor down by Houston to Lake Charles, but the jury is
still out for those areas. Higher confidence in heavy rainfall is
just north of there with the areas of the Piney Woods in east TX up
through I-20 into LA as the main targets at this juncture. High
FFG's will likely thwart considerable flood prospects, as well as
the setup promoting at least steady convective progress to lower
training concerns. That still doesn't mean those concerns would
alleviate at least scattered flash flood concerns, but there's
still more time to assess location specifics before interjecting an
upgrade at this time. For now, a broad MRGL risk was maintained,
but the threat will warrant some consideration of an upgrade as we
move closer in time and get into the CAMs temporal window(s).

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 061600
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1100 AM EST Fri Mar 6 2026

Day 1
Valid 16Z Fri Mar 06 2026 - 12Z Sat Mar 07 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE LOWER MISSISSIPPI VALLEY, INCLUDING THE ARKLATEX...

...16Z Update...
Minor adjustments overall made to the overnight forecast thinking.
Based on the 12Z HREF suite, the inhereted Slight Risk was
extended slightly northward into the Missouri Ozarks which
partially overlaps with an area of recent heavy rainfall.
Otherwise, the Marginal Risk in the Ohio Valley was removed as both
the HREF and RRFS suggest the threat of exceeding an inch of rain
(around the 1 HR FFG for the area) is below 5%.

Asherman

...Previous Discussion...

...ArkLaTex to Lower Mississippi Valley...

Highly amplified pattern across the western United States will
shift eastward today and tonight setting up a broad axis of
convective development downstream over the Southern Plains up into
the Midwest to the Mississippi Valley. Instability and moisture
being drawn northward from the Gulf gets in place ahead of an
approaching cold front that provides a focus for another round of
storm later today and tonight with heavy rainfall expected in a
well defined warm sector situated from the eastern half of Texas
into the Missouri Valley where precipitable water anomalies
pushing 2 or 3 standard deviations above normal for the time frame
should be in place. Ensemble bias corrected QPF from 06/00 remained
over 2 inches across the ArkLaTex with the convergence signal
strongest over the three-state region as the nocturnal Low Level
Jet is forecast to nose into the area promoting the most favorable
axis for organized convection and eventual cell mergers after
sunset. The previously issued Slight Risk was maintained with only
minor adjustments based on latest model guidance.

...Midwest...

Amplified pattern to the west will have impacts on the evolution
and related threat of excessive rainfall over the Upper Midwest as
a wavy boundary to the south lifts to the north as a warm front
later today and tonight. The combination of vertical wind shear and
the approach upper level shortwave will result in a deepening
surface low over Kansas later today which draws increasing moisture
and instability into the Upper Midwest later today and
tonight....resulting in convection capable of producing heavy
rainfall over the Missouri River Valley and points east. Any risk
for excessive rainfall should be offset a bit by quick storm
motion. 00Z HREF and RRFS both ramp up the probability for 1 inch
of accumulation early in the Day 1 period which moves off to the
northeast and dissipates this morning...followed by redevelopment
this evening in central and northeast Iowa. Provided an apron
around this area to account for uncertainty in where the convection
redevelops. As a result...the previous Marginal risk was largely
maintained with only minor adjustments.

Bann

Day 2
Valid 12Z Sat Mar 07 2026 - 12Z Sun Mar 08 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY...

The previously issued Slight risk across portions of Texas into
Mississippi was maintained given a consistent signal in the
numerical guidance of a corridor of heavy rainfall. The actual
extent and magnitude of the flash flood risk remains a bit
uncertain relating to how quickly activity propagates off to the
south and east. Some guidance supports a rather quick southward
propagation of convection, which could keep the flash flood risk
more isolated in nature. However, the 06/00Z guidance from both the
HREF and RRFS still maintain be an opportunity for some along axis
training even with some southward propagation. The HREF probability
was notably more aggressive with its neighborhood probabilities for
1 inch per hour rate than was the RRFS...especially at the start
of the Day 2 period but eventually converge on similar values on
Saturday afternoon. At that point the RRFS begins to increase
probabilities of 1 and 2 inch probabilities ahead of the front as
it sags southward (after the last forecast hour from the HREF). Thus
think there is enough going for this event to justify maintaining a
broad Slight risk with this update.

A Marginal risk was also extended as far north as western NY.
Plenty of moisture will advect northward along this corridor, with
as much as 500-1000 j/kg of CAPE as well. Thus while areal
averaged rainfall is not that impressive, there will be an
opportunity for locally heavy rates. With saturated conditions
over portions of the OH Valley, and some snow pack and frozen
ground over NY...these higher rates could be enough to locally
result in excess runoff and minor flood concerns.

Bann

Day 3
Valid 12Z Sun Mar 08 2026 - 12Z Mon Mar 09 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE GULF COAST REGION...

Deep moisture...instability and the risk of excessive rainfall
should be confined to a shrinking area as a cold front makes its
way southward on Sunday. Model guidance showed a corresponding
decrease in QPF and spaghetti plots from the SREF and the GEFS
maintaining a few members with probabilities of 2 inches in the 24
hour period ending at 12Z Monday from eastern Texas eastward. This
reflected a downward trend in the deterministic QPF. During the
latter half of the period...Gulf moisture starts to return
northward over southwestern Texas later in the period...so made a
westward expansion of the Marginal risk area.

Bann
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 070830
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
330 AM EST Sat Mar 7 2026

Day 1
Valid 12Z Sat Mar 07 2026 - 12Z Sun Mar 08 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY...

Maintained the Slight risk area from the Southern Plains into the
Lower Mississippi Valley and the Upper Texas coast...with an
expansion that effectively brought the Slight Risk area to the
Upper Texas coast and nearby Louisiana given the 07/00Z HREF and
RRFS probabilities for 24 hour rainfall 2-inch and 3-inch
thresholds. There were even a few neighborhood probabilities
exceeding 10 percent at the 5 inch threshold. Of course the actual
extent and magnitude of the flash flood risk remains a bit
uncertain relating to how quickly activity propagates off to the
south and east. Some guidance supports a rather quick southward
propagation of convection, which could keep the flash flood risk
more isolated in nature. The HREF guidance tended to side with the
faster solution and the RRFS was slower and was more aggressive
with its probabilities for 1- and 2-inch per hour rates. At this
point...tended to favor the HREF guidance and associated models
although can not entirely rule out the faster solutions.

A Marginal risk surrounding the Slight Risk area extended north and
east as far as western New York. There should be plenty of moisture
advectiving northward along this corridor, with as much as
500-1000 j/kg. Thus while areal averaged rainfall is not that
impressive, there will be an opportunity for locally heavy rates.
With saturated conditions over portions of the Ohio Valley, and
some snow pack and frozen ground over New York...any enhanced
rainfall rates could be enough to result in isolated/locally excess
runoff and minor flood concerns.

Bann


Day 2
Valid 12Z Sun Mar 08 2026 - 12Z Mon Mar 09 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE GULF COAST REGION...

Deep moisture...instability and the risk of excessive rainfall
should be confined to a shrinking area south of an approaching
cold front on Sunday. Model guidance showed a corresponding
decrease in QPF and spaghetti plots from the SREF and the GEFS
maintaining a few members kept neighborhood probabilities of 1 inch
or greater confined from Louisiana into Georgia with greatest
clustering from southern Mississippi into central and southern
Alabama with QPF spaghetti plots showing few members at 2 inch
amounts in 24 hours from either the SREF ir GEFS. In this portion
of the Marginal risk...there was good agreement between WPC and the
CSU machine learning first-guess ERO. The WPC Marginal Risk area
extended west along the Louisiana and Upper Texas coast if
deference to the HREF and RRFS runs which lingered some 1+ in per
hour rainfall along the coast and even some 2 inch per 6 hour
lingering through at least 08/18Z. In addition...Gulf moisture
starts to return northward over southwestern Texas later in the
period...also supporting a westward expansion.

Bann


Day 3 Valid 12Z Mon Mar 09 2026 - 12Z Tue Mar 10 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHEAST UNITED STATES...

The front which had been moving from west to east in the Day 1 and
Day 2 period will slow its forward motion and become oriented along
a west to east axis on Monday and the start to inch northward
Monday afternoon and Monday night. There is a wide range of
solutions in where convection could fire along that boundary which
limits confidence. However...confidence is higher in the occurrence
of showers and thunderstorms occurring rather than details of where
that could happen given precipitable water values approaching 1.75
inches ready to to be lifted isentropically above the front as low
level flow becomes southerly. The area should become better focused
in subsequent outlooks.


Bann
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)

FOUS30 KWBC 072322
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
622 PM EST Sat Mar 7 2026

Day 1
Valid 01Z Sun Mar 08 2026 - 12Z Sun Mar 08 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF
THE CENTRAL GULF COAST...


Mainly due to convective progression, there has been a significant
shrinking in both the Marginal and Slight Risk areas. The
mesoscale guidance most suggests that heavy rain issues from 01z
onward lie from the Upper TX Coast eastward towards Mobile. The
degree of moisture, instability, and effective bulk shear available
near and equatorward of a cold front continues to support the
potential for hourly rain amounts to 2.5" with local totals to 4".

While not depicted as a separate Slight Risk, mainly because it's
out in Brush Country, portions of interior South TX have a chance
in the very near term for heavy rainfall as well. Although they are
included in the Marginal Risk category, it's a higher end Marginal
Risk in that area. Overall, much of the rainfall expected is
beneficial, relieving long term drought conditions. The intensity
of organized convection and where storms can train and/or merge
would threaten urban areas most.

Roth


Day 2
Valid 12Z Sun Mar 08 2026 - 12Z Mon Mar 09 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE GULF COAST REGION...

2100 UTC update:

No changes made to the previous marginal risk area across the Gulf
coast region.

Oravec

Previous discussion:

Deep moisture...instability and the risk of excessive rainfall
should be confined to a shrinking area south of an approaching
cold front on Sunday. Model guidance showed a corresponding
decrease in QPF and spaghetti plots from the SREF and the GEFS
maintaining a few members kept neighborhood probabilities of 1 inch
or greater confined from Louisiana into Georgia with greatest
clustering from southern Mississippi into central and southern
Alabama with QPF spaghetti plots showing few members at 2 inch
amounts in 24 hours from either the SREF ir GEFS. In this portion
of the Marginal risk...there was good agreement between WPC and the
CSU machine learning first-guess ERO. The WPC Marginal Risk area
extended west along the Louisiana and Upper Texas coast if
deference to the HREF and RRFS runs which lingered some 1+ in per
hour rainfall along the coast and even some 2 inch per 6 hour
lingering through at least 08/18Z. In addition...Gulf moisture
starts to return northward over southwestern Texas later in the
period...also supporting a westward expansion.

Bann


Day 3
Valid 12Z Mon Mar 09 2026 - 12Z Tue Mar 10 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE LOWER MISSISSIPPI VALLEY INTO THE UPPER TENNESSEE VALLEY...

2100 UTC update:

Only some minor changes made to the marginal risk area from the
Lower Mississippi Valley into the Upper Tennessee Valley. Changes
made were to cover the latest qpf spread for locally heavy precip
totals day 3 across these regions.

Oravec

Previous discussion:

The front which had been moving from west to east in the Day 1 and
Day 2 period will slow its forward motion and become oriented along
a west to east axis on Monday and the start to inch northward
Monday afternoon and Monday night. There is a wide range of
solutions in where convection could fire along that boundary which
limits confidence. However...confidence is higher in the occurrence
of showers and thunderstorms occurring rather than details of where
that could happen given precipitable water values approaching 1.75
inches ready to to be lifted isentropically above the front as low
level flow becomes southerly. The area should become better focused
in subsequent outlooks.


Bann
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 090822
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
422 AM EDT Mon Mar 9 2026

Day 1
Valid 12Z Mon Mar 09 2026 - 12Z Tue Mar 10 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE LOWER MISSISSIPPI VALLEY & SOUTHEAST...

Model agreement has started to increase QPF-wise and the present
Marginal Risk area was adjusted to fit the broad pattern of
potentially heavy rainfall advertised by the 09/00Z runs of both
the HREF and REFS guidance. Precipitable water values approaching
1.75" return somewhat northward as low level flow begins to back
and accelerate in the lower levels. It appears that enough
moisture, instability, and effective bulk shear will be present
near the lower level section of a frontal zone for hourly amounts
to approach or even exceed 2 inches. Flash flood guidance has
lowered due to heavy rainfall on Saturday and Saturday night/early
Sunday morning to partially saturated soils. However, the
mesoscale guidance signal for 3"+ is low enough at the present time
to remain in the Marginal Risk category as any flash flooding
impacts appear no better than isolated to widely scattered.

Bann


Day 2
Valid 12Z Tue Mar 10 2026 - 12Z Wed Mar 11 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE CENTRAL UNITED STATES FROM THE PLAINS TO THE SOUTHERN GREAT LAKES...

Gulf moisture gets drawn northward over parts of the central U.S.
from Texas into the Upper Mississippi Valley and southern Great
Lakes region in response to circulation around an upper level low
over the Southwest U.S.. This moisture will encounter a southward
moving cold front from the Upper Midwest and an area of low
pressure along the front over Kansas or Nebraska on Tuesday. This
combination should result in convection being capable of producing
some heavy rainfall rates that results in run off or flooding
concern across the southern & central Plains and somewhere in the
neighborhood of the Midwest and/or Ohio Valley. The better
instability...and higher rainfall rates...look to be over the
southern part of the outlook area given better instability and due
to increasingly diffluent flow aloft as the Southwestern U.S. upper
low approaches. Farther north...the concern for excessive rainfall
comes from stronger synoptic scale forcing due to the approach of
an amplifying trough in the northern stream.

Based on increasing numerical guidance agreement from the
09/00Z runs...felt confident enough to separate the one Slight
risk area from yesterday's Day 2 outlook into two Slight risk areas today.

Some places within each Slight Risk received heavy to excessive
rainfall in the past few days which has added to soil saturation
across portions of the Midwest, the Ohio Valley and the Mid-
Mississippi Valley. Not enough confidence yet to expand the area
deeper into the Midwest/Ohio Valley due to the lack of any notable mid-
level capping but the possibility remains.

Bann


Day 3
Valid 12Z Wed Mar 11 2026 - 12Z Thu Mar 12 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHERN MISSISSIPPI VALLEY/SOUTHEAST UNITED STATES AND PARTS
OF THE COASTAL PACIFIC NORTHWEST...

...Southern US...
Maintained a Marginal Risk area over portions of the southern
states as an upper low propagates eastward on Wednesday. The upper
level support for heavy rainfall should be waning with time as the
upper low undergoes slow weakening and filling. Even so...enough
low level moisture will be in place as mid-level lapse rates
steepen and increases instability at the time of maximum heating.

...Pacific Northwest...
Persistent on-shore flow of deep moisture into parts of coastal
Washington and northern Oregon should result in occasional moderate rainfall...mainly in the west face of the coastal ranges. Amounts
on the order of 2.5 inches to 3.5 inches in 24 hours is forecast
which could result in isolated flooding ot run off problems in
areas of poor drainage.

Bann
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 100822
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
422 AM EDT Tue Mar 10 2026

Day 1
Valid 12Z Tue Mar 10 2026 - 12Z Wed Mar 11 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE SOUTHERN AND WESTERN PLAINS AND OVER PARTS OF THE SOUTHERN GREAT LAKES...

The signal for potentially two heavy precip axes persists in the
guidance..in the very favorable coupled jet entrance/exit regions
expected between the southern stream closed low moving into the
Southern Plains and the northern stream jet across Mid Mississippi
Valley and the Midwest region.

Gulf moisture gets drawn northward over parts of the central U.S.
from Texas into the central portion of the Mid-Mississippi Valley
during the day. There has been a trend in the model guidance over
the past 24 hours for the core of the higher precipitable water
values to get shunted more eastward than northeastward...resulting
in lower model QPF despite the upper support and mid-level
mesoscale forcing remaining favorable. Consequently...trimmed the
Slight Risk area to cover only portions of Illinois and Indiana
where QPF exceeded an inch and which overlapped areas that
experienced moderate to heavy rainfall a few days ago and have
suppressed flash flood guidance.

The better instability...and associated higher rainfall
rates...still look to be over portions of Texas into southeast of
Oklahoma as flow aloft becomes increasingly difluent in response to
an approaching upper low. .Mixed layer CAPE values of 1500 to
around 2500 J per kg develop ahead of the low where precipitable
water values will have risen into the 1.25 to 1.5 inch range
resulting in the potential for 1+ inch per hour rates. The axis of
model QPF and WPC deterministic QPF align well with modestly-
lowered flash flood guidance from rainfall several days ago.

Bann


Day 2
Valid 12Z Wed Mar 11 2026 - 12Z Thu Mar 12 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE
SOUTHERN US...

The upper low over the southern states will continue to translate
eastward on Wednesday. The upper support will be weakening as the
system weakens/fills with time. Model run to run consistency has
been poor and another round of changes were made this cycle. The
changes included introduction of a Slight Risk over parts of
eastern Texas and western Louisiana where model QPF exceeded two
inches. In addition...there was some overlap between locally heavy
rainfall a couple of days ago and the QPF.

...Pacific Northwest...
Persistent on-shore flow of deep moisture into parts of coastal
Washington and northern Oregon should result in occasional moderate rainfall...mainly in the west face of the coastal ranges. Amounts
on the order of 2.5 inches to 3.5 inches in 24 hours is forecast
which could result in isolated flooding ot run off problems in
areas of poor drainage.

Bann


Day 3
Valid 12Z Thu Mar 12 2026 - 12Z Fri Mar 13 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE NORTHWEST UNITED STATES...

...Pacific Northwest...
On-shore flow of deep moisture into parts of coastal Washington
and northern Oregon persists into the Day 3 period that results in
occasional moderate to locally heavy rainfall continuing along the
coastal ranges. An additional 1 to 3 inches in 24 hours are
possible...which could result in isolated flooding ot run off
problems in areas of poor drainage.

Bann
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 110827
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Wed Mar 11 2026

Day 1
Valid 12Z Wed Mar 11 2026 - 12Z Thu Mar 12 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE
SOUTHERN US...

As the closed low moves across the central and eastern Texas
today...an axis of training convection should persist from the
eastern part of Texas into the lower Mississippi Valley. With very
strong synoptic forcing and increasing moisture transport we
should see convection expand in coverage and intensity over eastern
Texas by mid- to late-morning. During the development phase cell training/backbuilding is probable over east TX, and while
convection should grow upscale and forward propagate during the
afternoon, some west to east training is possible near the
southward dropping cold front. The inherited Slight risk was
expanded off to the south and east once again to account for model
trends into parts of Mississippi and western Alabama.

Only minor nudges were needed to the Marginal risk area across the
Ohio Valley and into western New York where rainfall rate driven
localized flash flooding is possible. Areal averaged rainfall is
only 0.5"-1.5", but given the 500-1000 j/kg and convective nature
of rainfall, the possibility of localized swaths of rainfall
exceeding 2 inches persists. This should be enough to at least
locally exceed FFG across this region. Over western NY, snow melt
and locally heavy rain may combine to result in areas of excessive runoff.

Chenard/Bann


Day 2
Valid 12Z Thu Mar 12 2026 - 12Z Fri Mar 13 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

Coastal Areas of Washington into Northwest Oregon...

Only change was to nudge the Marginal risk back to the west just a
bit given the placement of heavier snowfall in the Cascades.
Despite that change...much of the shift made by the previous shift
was retained in this outlook.

On-shore flow of deep moisture into parts of coastal Washington
and northern Oregon persists into the Day 2 period...with occasional
moderate to locally heavy rainfall continuing along the coastal
ranges. An additional 1 to 3 inches of rainfall in 24 hours is
possible...which could result in isolated flooding ot run off
problems in areas of poor drainage.

Bann


Day 3
Valid 12Z Fri Mar 13 2026 - 12Z Sat Mar 14 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

The on-shore flow which has been anchored along coastal portions
of Washington and northern Oregon will finally start to shift its
focus southward a bit from Friday into early Saturday morning. The
axis of a precipitable water plume with values of 0.75 to 1.00
inches will gradually be shifting southward into Oregon which
allows precipitation rates to weaken farther north. With the rain
moving into an area with drier antecedent condition...maintained a
Marginal Risk area.

Bann
$$
d
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 120821
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
421 AM EDT Thu Mar 12 2026

Day 1
Valid 12Z Thu Mar 12 2026 - 12Z Fri Mar 13 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

An axis of anomalous PW and 850-700 mb moisture flux
values...1.5-2.5+ and 2 to 4+ standard deviations above the mean,
respectively, will continue to impact southern WA state into
northern Oregon from the Cascades westward to the Coast Ranges.
Hourly rainfall rates are not expected to be very impressive, at
most .10-.25"+. However, there is not expected to be a lot of
movement, overall with this anomalous onshore flow, which will
support rain for nearly all of the day 1 period in this axis.
Heaviest precip likely in the upslope of the southern WA Cascades
and far northern OR Cascades, where HREF and RRFS neighborhood
probabilities are high for 2 and 3"+ amounts day 1. Changes to the
previous outlook were to trim the marginal risk southward out of
coastal southern WA, and through the Willamette Valley to better
match the latest model qpf consensus.

Oravec


Day 2
Valid 12Z Fri Mar 13 2026 - 12Z Sat Mar 14 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

Not a lot of changes expected overall to the large scale flow
pattern off the northeast Pacific into portions of the Pacific
Northwest day 2. The ongoing atmospheric river event will continue
through much of the day 2 period, with the axis of anomalous PW
and 850-700 mb moisture flux values...1.5-2.5+ and 2 to 4+
standard deviations above the mean, respectively, again impacting
areas from southern WA state into northern Oregon from the Cascades
westward to the Coast Ranges. Similar to the day 1 period, the
hourly rainfall rates are not expected to be very impressive, at
most .10-.25"+. However, there will continue to be little overall
movement with this anomalous onshore flow axis, which will support
additional heavy rainfall amounts in the upslope of the northern
OR/southern WA Cascades and the northern OR Coast Range. Changes to
the previous outlook were to trim the marginal risk area over
southern WA and remove it from the Willamette Valley to better
match the latest model qpf consensus.

Oravec


Day 3
Valid 12Z Sat Mar 14 2026 - 12Z Sun Mar 15 2026

The probability of rainfall exceeding flash flood guidance values
is less than 5 percent.

Oravec
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 130745
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
345 AM EDT Fri Mar 13 2026

Day 1
Valid 12Z Fri Mar 13 2026 - 12Z Sat Mar 14 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

Final day of impact from a continuous AR regime that has doused the
Pacific Northwest with several inches of precipitation the last
72+ hours. Continued fetch off the Pacific will maintain its
composition for another period with a slow shift south in the
primary moisture advection regime as the approach of a final, yet
potent shortwave helps press against the prevailing height field
situated across the Pacific Northwest into British Columbia. A
modest 600-800 kg/ms IVT signature has been persistent within a
zone oriented from Olympia down towards the WA/OR border.
Expectation is for the IVT advection pattern to pivot south to
include more of northwest OR extending inland into the southern WA
and northern OR Cascades leading to an extended moderate
precipitation band through Friday into early Saturday.

Current rates are still subject to be focused between 0.25-0.5"/hr
at peak intensity with perhaps a few localized areas within the
upslope regions of the Cascades to breach closer to 0.6-0.75/hr at
times. This alone falls below the FFG criteria for the region,
however its the longevity and recent priming that would tip the
scales towards a low-end flash flood scenario, especially within
the confines of any urbanized zones. Downsloping into the
Willamette Valley should cause a regional min with this setup
leading to lower probabilities of any flood concerns in the
shadowed zone. City of Portland remains right on edge of persistent
rain bands and waves of moderate rainfall with the heaviest likely
to focus closer to Astoria and over into the adjacent Cascades
thanks to the upslope component. D1 QPF indicates the sharp
delineation in the split maxima with Portland proper right on the
edge of the higher totals. Considering a solid run-to-run
continuity across guidance the past 24-36 hours, there wasn't
really any reason to deviate from the previous MRGL risk
inheritance as 2-4" of rainfall with local maxima of 6" possible in
the Cascades are enough to warrant at least a low-end risk.

Kleebauer


Day 2
Valid 12Z Sat Mar 14 2026 - 12Z Sun Mar 15 2026

The probability of rainfall exceeding flash flood guidance values
is less than 5 percent.

Kleebauer


Day 3
Valid 12Z Sun Mar 15 2026 - 12Z Mon Mar 16 2026

The probability of rainfall exceeding flash flood guidance values
is less than 5 percent.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 131550
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1150 AM EDT Fri Mar 13 2026

Day 1
Valid 16Z Fri Mar 13 2026 - 12Z Sat Mar 14 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
THE PACIFIC NORTHWEST...

16Z Update...

Generally no change to the previous thinking concerning the long-
duration atmospheric river impacting the Pacific Northwest.
However, we did proceed with adding a second Marginal Risk area to
portions of southeast WA, northeast OR and west-central ID to
account for heavy rains persisting at some of the lower elevations
across these areas since the inland core of stronger IVT
magnitudes continue to impact this region. Antecedent conditions
across these areas have become increasingly sensitive with the
rainfall of the past couple days, and given high streamflows, the
additional rains here may encourage some localized flooding concerns.

Orrison

Previous discussion...

Final day of impact from a continuous AR regime that has doused the
Pacific Northwest with several inches of precipitation the last
72+ hours. Continued fetch off the Pacific will maintain its
composition for another period with a slow shift south in the
primary moisture advection regime as the approach of a final, yet
potent shortwave helps press against the prevailing height field
situated across the Pacific Northwest into British Columbia. A
modest 600-800 kg/ms IVT signature has been persistent within a
zone oriented from Olympia down towards the WA/OR border.
Expectation is for the IVT advection pattern to pivot south to
include more of northwest OR extending inland into the southern WA
and northern OR Cascades leading to an extended moderate
precipitation band through Friday into early Saturday.

Current rates are still subject to be focused between 0.25-0.5"/hr
at peak intensity with perhaps a few localized areas within the
upslope regions of the Cascades to breach closer to 0.6-0.75/hr at
times. This alone falls below the FFG criteria for the region,
however its the longevity and recent priming that would tip the
scales towards a low-end flash flood scenario, especially within
the confines of any urbanized zones. Downsloping into the
Willamette Valley should cause a regional min with this setup
leading to lower probabilities of any flood concerns in the
shadowed zone. City of Portland remains right on edge of persistent
rain bands and waves of moderate rainfall with the heaviest likely
to focus closer to Astoria and over into the adjacent Cascades
thanks to the upslope component. D1 QPF indicates the sharp
delineation in the split maxima with Portland proper right on the
edge of the higher totals. Considering a solid run-to-run
continuity across guidance the past 24-36 hours, there wasn't
really any reason to deviate from the previous MRGL risk
inheritance as 2-4" of rainfall with local maxima of 6" possible in
the Cascades are enough to warrant at least a low-end risk.

Kleebauer


Day 2
Valid 12Z Sat Mar 14 2026 - 12Z Sun Mar 15 2026

The probability of rainfall exceeding flash flood guidance values
is less than 5 percent.

Kleebauer


Day 3
Valid 12Z Sun Mar 15 2026 - 12Z Mon Mar 16 2026

The probability of rainfall exceeding flash flood guidance values
is less than 5 percent.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 151906
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
306 PM EDT Sun Mar 15 2026

Day 1
Valid 16Z Sun Mar 15 2026 - 12Z Mon Mar 16 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
SOUTHEAST PENINSULAR FLORIDA...

16Z Update...

The previous forecast remains largely on track based on the latest
12Z HREF/06Z REFS guidance and recent HRRR solutions which
continue to depict small-scale clusters of locally heavy showers
and thunderstorms across the central and southern portions of the
FL Peninsula. The Marginal Risk for the more sensitive southeast FL
urban corridor will be maintained.

Satellite and radar imagery shows convection rapidly developing and
expanding across portions of the Midwest ahead of the deepening low
center transiting the region. Very progressive cell-motions are
still expected to generally keep rainfall totals to a modest level
at least through this afternoon. There may be some potential for
some localized cell-training with convection associated with the
low track this evening across areas of northern IL, northwest IN
and into southwest Lower MI, but the latest guidance generally
indicates rainfall amounts through this evening peaking in the 1 to
2 inch range. The latest FFG exceedance probabilities here are
very low, and therefore we will continue to hold off on any upgrade
to a Marginal Risk. However, conditions will be closely monitored
with today's expected organized convective outbreak. If guidance or satellite/radar trends support heavier short-term QPF, an upgrade
later today or early this evening could still be necessitated.

Orrison

Previous discussion...

A very strong dynamic cyclone will be in full force across the
Upper Midwest and Upper Great Lakes with a strong attendant cold
front crossing out of the Plains through the Lower Ohio and
Mississippi Valley. The strength of the low level flow prior to the
cold front will draw modest moisture through the Valleys to provide
1-1.25" Total PWat values. The focus will be on severe aspects of
the convective line and there will be some stronger updrafts and
solid moisture flux convergence associated with these convective
cores capable of sub-hourly to hourly rates/totals in the vicinity
of 1-1.5"; the duration will be brief to limit overall totals to
less than 2" overall. This could result in random, widely spaced
incident or two of flash flooding, but limited to urban and
traditionally flood prone locations. So while there is a non-zero
risk of excessive rainfall, it remains below the 5% coverage for a
Marginal Risk to be delineated at this time but will continue to
monitor trends for subsequent updates.

Further southeast, the draw of moisture out of the Caribbean
through the Strait of Yucatan will draw higher moisture though the
eastern Gulf. Combined with return easterly flow north of the
Greater Antilles into the Bahamas; there is an increase in
moisture confluence (total PWats to 1.75") through Peninsular
Florida. Onshore flow from the southeast and clearing skies will
allow for some increased instability (1250-1500 J/kg) to build for
thunderstorm activity across the southern Peninsula before evening.
Rates in excess of 2"/hr may result in highly localized spots of
2-5" that may result in localized rapid inundation flooding if over
the southern I-95 urban corridor. Converging sea-breezes may also
result in mergers across the central Peninsula from north to south,
but are likely to be more intense initially but also much more
brief relative to those closer to coastal convergence zones that
may allow for longer duration. HREF probabilities of 3-5"/24hrs are
sufficient to highlight a small Marginal Risk of Excessive
Rainfall.

Gallina


Day 2
Valid 12Z Mon Mar 16 2026 - 12Z Tue Mar 17 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MID-ATLANTIC AND NORTHEASTERN U.S & EXTREME NORTHWEST WASHINGTON...

19z Update: Forecast looks on track. Nothing in the 12z high res
guidance supports any changes to the inherited Marginal risk areas.

Chenard

...Mid-Atlantic into Northeast...
Highly meridional moisture surge will be already ongoing at the
start of the forecast period (16.12z) as the leading edge of the
Atlantic warm front should be lifting through southern New England
and Gulf of Maine. Upstream the highly dynamic cyclone will be well
occluded through depth across the north-central Great Lakes with a
powerful near 980mb surface low and attendant sharp cold front
extending due south across the Mid-Ohio Valley, Cumberland Plateau
into the central Deep South. The based of the large scale trough
will be lifting northeastward providing solid dPVA to support
strengthening deep layer southerly flow further compounding on the
initial warm advective surge through out of the Southeast through
the Mid-Atlantic. Integrated Vapor Transport (IVT) values will
increase from upper hundreds of kg/m/s toward 1250 kg/m/s across
the Coastal Plain into southern New England eventually reaching
values over 1400 kg/m/s after 00z through S ME due to the combining
strength of the LLJ and confluent moisture streams off the Eastern
Gulf and Western Atlantic. This brings moisture flux well above
97-99th+ percentiles of moisture flux. Instability will be a
limiting factor for vertical development along/ahead of the cold
front but some 250-750 J/kg will be available through the central
Mid- Atlantic with some localized convergence for scattered showers
and thunderstorms prior to the main cold front/squall line to
emerge out of the Appalachian terrain by mid-day. These initial
cells should be quick moving and limited in total, but any that
broaden into stronger isolated super-cells may have capability for
locally intense rates prior to the main line. Still, the main focus
will be the hourly to sub- hourly 1-1.5+" totals with the main
convective line that will have greatest potential for localized,
mainly minor flash flooding impacts.

Hydrologically, the Northeast remains highly saturated and cold
through depth with modest SWE in some remaining snow pack. So,
while the rain rates will likely be much lower due to lack of deep unstable/vertical shower activity; the orographic ascent and should
remain concerning that any rain on snow will further compound the
ongoing hydrologic/stream rises (please refer to National Water
Center FHO and Local River Forecast Center forecasts for further
river concerns across this region).

As such a broad Marginal Risk will remain in place for nearly all
of the Northeast (minus areas in south to south-southwest rain
shadow areas of far N VT), with an extension of the Marginal into
the Potomac River Valley and southern extents of the Megalopolis
where those higher rates/short-burst totals may result with
localized exceedance of lower hourly FFG values.

...Pacific Northwest...
Prolonged warm advection of a moderate positively anomalous
moisture stream will be continuing across the extreme northwestern
portion of the Olympic Peninsula with a very weak continuation to
the northern Washington Cascades. Rates will remain fairly
consistent between .25"-.33"/hr allowing for totals to near 3-5"
toward the the end of the forecast period with 00z HREF probability
of 5" nearing 30%; though 5"/24hr just across the Sound will be
near 60%. By late evening/early overnight period, the cold front
will be starting to surge southeastward and further direct enhanced
moisture flux toward the Olympic Peninsula after 06z, with 1-1.25"
Total PWats fluxed on 40-45kts of flow generally resulting in about
750 kg/m/s IVT values, bringing rates locally up to .5" for the
best orographic ascent regions. As such, a very small Marginal Risk
was included for this AR surge into an area already at above
average soil saturation due to recent AR plumes in the last few
days/week(s).

Gallina


Day 3
Valid 12Z Tue Mar 17 2026 - 12Z Wed Mar 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
NORTHWEST WASHINGTON...

19z Update: Marginal risk looks on track, thus no changes needed.

Chenard

At the start of the day 3 forecast period, 18.12z, the strong,
prolonged Atmospheric River had recently shifted slightly eastward
directing the core of the AR plume centered across Northwest
Washington into the northern Cascades, oriented from SW to NE. Deep
layer moisture remained well above normal with total PWat values
remaining well above 1" with 1.25" reaching the southwest flanks of
the Olympic Range. Winds had calmed a tad but remain around or
above 40kts through the 850-700mb range favorably orthogonal to the
Olympic Range. Freezing levels are well above even the highest
peaks, exposing some Snow Water Equivalent (SWE) to the higher WAA southwesterly flow adding to the .25"-.33"/hr rain rates though
will be higher earlier in the period as winds slack ever so subtly
between shortwave features. Overall IVT values will remain above
500 kg/m/s with peak values over 750 that extend into the northern
Cascades as well. As such, 24hr totals will once again be over 3-4"
and combined with the snow melt, could further increase stream
flows. With lower rates, a Marginal Risk of Excessive Rainfall will
remain in place; however, please refer the National Water Center
and NWRFC forecasts for stream/river flow/rise information with
respect to increasing flooding potential.

Gallina
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 160730
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
330 AM EDT Mon Mar 16 2026

Day 1
Valid 12Z Mon Mar 16 2026 - 12Z Tue Mar 17 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MID-ATLANTIC AND NORTHEASTERN U.S...

Broad axis of diffluence positioned over the Ohio Valley into the
Northeast will lead to multiple rounds of convection once east of
the Appalachian front. Warm moist air will continue to funnel
poleward ahead of a very amplified trough axis centered over the
Midwest to Mid-Mississippi Valley. PWATs across the Mid Atlantic
have already surged beyond 1", a solid 3 standard deviations above
normal compared to climatology putting into the 97-99th percentile
for mid-March. Expectation is for this surge to continue pushing
further north within the amplified flow east of the Mississippi
leading to a large swath of the east coast to exhibit an
environment favorable for at least the threat of heavy rainfall.

A multi-round scenario of convective impacts are anticipated as
weak mid-level perturbations usher north-northeast ahead of the
mean trough and cold front migrating through the Ohio Valley. Prior
to the cold front arrival and associated precip field along and
ahead of the front, moderate to locally heavy rains from
convective clusters could help prime local soils before the main
time frame of impact after 18z occurs. One of the trends within
guidance was a relatively skinny convective segment that will be
the main player in the higher rates exhibited in this setup. The
linear segment will be relatively progressive, but rates between
0.75-1.5"/hr at peak intensity are plausible as it moves through
the Mid Atlantic and Northeast leading to a threat for flash
flooding as it migrates into the Piedmont and urban zones
characterized within the Northeastern Megalopolis. Areal average
of 0.75-1.5" is forecast for much of the area from northern VA up
into NY state and Northeast New England. The maxima of over 2" is
still showing up within deterministic output via both global and
CAMs physics. The area of interest continues to point to
CT/RI/Southern MA as the primary spot for more appreciable totals

2". This is supported via the neighborhood prob fields of 50-80%

for at least 2" by the latest 00 HREF output. Other notable areas
include high probs >70% for at least 1" aligned along the Blue
Ridge to the I-95 corridor for VA/MD/PA extending into the Lower
Hudson and Catskills area of NY state. Another axis of higher probs
exists across eastern ME and parts of Northern New England which
coupled with high SWE presence should allow for rapid snow melt and
potential for local hydrologic issues stemming from both the
precip and snow/ice melt. This signal was sufficient for
maintenance of the previous MRGL risk with only some minor
adjustments on the southern edge of the risk area to account for
the latest model trends.

The progressive nature of the precip should curb some of the flash
flood concerns making this a solid MRGL risk with perhaps a bump in
the risk magnitude if guidances trends more aggressive in QPF
output. For now, this is a classic setup for early spring
convection and modest flash flood prospects.

Kleebauer


Day 2
Valid 12Z Tue Mar 17 2026 - 12Z Wed Mar 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Active pattern across the Gulf of Alaska will lead to another AR
contribution into portions of the Pacific Northwest as the main
IVT surge will adjust south into WA state after impacting
neighboring British Columbia the day prior. Looking at IVT values
between 500-700 kg/ms across northwest WA state with the surge
propagating far enough inland to impact the Northern Cascades.
Rainfall amounts between 2-3" will be common in the hardest hit
areas, mainly into the Olympic Peninsula, Chehalis River valley,
as well as the Cascades to the east of Seattle. Rates will lack
vigor to the point for a more substantial impact, so the threat is
mainly due to prolonged moderate to locally heavy rain prospects
falling over relatively moist soil layer present after being
impacted for weeks leading in. The previous MRGL risk was generally
unchanged with the threat leaning towards the lower-end of the risk
threshold. Areal hydrologic concerns are still viable with river
and small stream flooding the most notable potential impacts.

Kleebauer


Day 3
Valid 12Z Wed Mar 18 2026 - 12Z Thu Mar 19 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Occluded low over the Gulf of Alaska a strong mid-level ridge
positioned across the Southwest U.S. will lead to a continued
transport of modest IVT into WA state for the D3 period. AR
dominated pattern will enhance rainfall prospects for the northern
half of WA leading to cumulative rainfall totals breaching 4" in
spots within the Northern Cascades, Olympics, and adjacent coastal
areas of northwest WA. Real concern is the growing hydrologic
factors with river flooding coupled with moderate rainfall posing a
problem for areas around the main rivers and tributaries for the
aforementioned areas. Flash flood threat remains low due to the
rates anticipated with the rainfall as hourly rainfall will remain
<0.5"/hr for a majority of Wednesday. However, the coupling of the
previous days rain and the already saturated soils will likely lead
to some hydro concerns mid-week, so maintained the previous MRGL
risk inherited with only some minor tweaks at the southwest edge of the risk.


Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 170741
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
341 AM EDT Tue Mar 17 2026

Day 1
Valid 12Z Tue Mar 17 2026 - 12Z Wed Mar 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Active pattern across the Gulf of Alaska will lead to another AR
contribution into portions of the Pacific Northwest as the main
IVT surge will adjust south into WA state after impacting
neighboring British Columbia the past 24-48 hours. IVT forecast
remains consistent within guidance as values between 500-700 kg/ms
are expected across northwest WA state with the surge propagating
far enough inland to impact the Northern Cascades. Rainfall amounts
between 2-3" will be common in the hardest hit areas, mainly into
the Olympic Peninsula, Chehalis River valley, as well as the
Cascades to the east of Seattle. Latest 00z HREF neighborhood
probabilities for >2" of rainfall over the course D1 are running
between 50-70% across the Olympic Peninsula into the Chehalis River
basin where Flood Watches have been issued for the upcoming AR.

Probabilities for the Northern Cascades are more robust for the
same 2" threshold, running between 70-90+% across the entire area
from Mount Rainier up to the Canadian border. Greater than 3"
probs are modest between 50-70% in those interior terrain areas,
including the highest elevations of the Olympics. Snow levels are
forecast to be around 8000ft MSL leading to a large portion of the
mountain ranges to see ample rainfall and snow melt that will
contribute to higher run off prospects. Rainfall rates will lack
vigor to the point for a more substantial impact, so the threat is
mainly due to prolonged moderate to locally heavy rain prospects
falling over relatively moist soil layer present after being
impacted for weeks leading in coupled with the expected snow melt.
The previous MRGL risk was generally unchanged with the threat
leaning towards the low to mid level of the risk threshold. Areal
hydrologic concerns are still viable with river and small stream
flooding the most notable potential impacts as forecasts around
some of the major river basins, including the Chehalis River, are
expected to reach into Action stage and even some minor river flood forecasts.

Be sure to check into the latest forecasts from the local Seattle
WFO and the National Water Center for the latest on the river
flooding threat.

Kleebauer


Day 2
Valid 12Z Wed Mar 18 2026 - 12Z Thu Mar 19 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Occluded low over the Gulf of Alaska and a strong mid-level ridge
positioned across the Southwest U.S. will lead to a continued
transport of modest IVT into WA state for the D2 period. AR
dominated pattern will enhance rainfall prospects for the northern
half of WA leading to cumulative rainfall totals breaching 4" in
spots within the Northern Cascades, Olympics, and adjacent coastal
areas of northwest WA. Real concern is the growing hydrologic
factors with river flooding coupled with moderate rainfall posing a
problem for areas around the main rivers and tributaries for the
aforementioned areas. Flash flood threat remains lower end by
definition due to the rates anticipated with the rainfall as
hourly rainfall will remain <0.5"/hr for a majority of Wednesday.
However, the coupling of the previous days rain and the already
saturated soils will likely lead to some hydro concerns mid-week,
especially for the Chehalis River basin and the rivers/stream
connected with the Northern Cascades as they encounter the tandem
of rainfall and snow melt. Maintained the previous MRGL risk
inherited with no modifications necessary as the forecast remains on track.

Kleebauer


Day 3
Valid 12Z Thu Mar 19 2026 - 12Z Fri Mar 20 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Persistent onshore flow within a zone focused between a broad
occluded cyclone in the Gulf of Alaska and a stout ridge axis
focused over the Southwestern U.S. will lead to a prevailing
moderate rain setup over much of the same areas impacted the
previous periods. Total rainfall in the Northern Cascades over into
the Olympic Peninsula will run between 4-7" with local amounts to
9" possible in the 72 hour time frame of the AR. The same impact
scenarios apply with the focus being a compounding factor of
rainfall, snow melt, and prolonged run off into local rivers and
streams that could result in flooding prospects for multiple days
as river levels reach action stage and minor to even moderate flood
stages. It will be important to maintain awareness on local river
conditions as the additional rain will exacerbate any receding
potential within the river basins. Highest impacted zone will
continue to be the Chehalis River basin where Flood Watches are in
effect for multiple days due to the prolonged AR and river levels
continue to run high after several weeks of rainfall. Additional
watches are in effect over the Northern Cascades due to anticipated
run off from rain and snow melt leading to newer hydro concerns as
the event wears on.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 180739
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
339 AM EDT Wed Mar 18 2026

Day 1
Valid 12Z Wed Mar 18 2026 - 12Z Thu Mar 19 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Persistent AR across WA state will lead to bouts of moderate to
occasionally heavy rainfall across the Olympic Peninsula into the
Northern Cascades. Down-sloping will reflect a general min across
the Seattle area, but the terrain will be susceptible to ongoing
rain prospects and totals between 1-3" for the day. This is an ongoing
threat that will carry on beyond the period adding a compounding
factor to the hydrologic responses anticipated across the River
basins within northwest WA. High snow levels ~8000ft MSL will lead
to snow melt across the higher elevations within the Northern
Cascades and Olympic Mountain ranges to couple with the rainfall.
This excessive run off will be another factor in the additional
water sources that will drain into nearby streams and rivers that
will induce at least several action stage responses and some minor
to borderline moderate river flooding across the region. The
primary river of impact will continue to be the Chehalis River
where minor flooding is already occurring and additional elevated
stream flows and run off entering into the tributaries will
eventually cause the crests of the river to slowly rise. Flood
Watches are in effect across portions of northwest WA state,
including Mason county where the greatest focus of flooding will
occur around the Chehalis River. Considering the hydrologic factors
at play despite rates only topping out around 0.5"/hr at peak
intensity, a MRGL risk was carried over for the period with little
to no change from the previous risk issuance.

Kleebauer


Day 2
Valid 12Z Thu Mar 19 2026 - 12Z Fri Mar 20 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

There are no changes from the prior forecast as the overall synoptic
pattern remains consistent in run-to-run continuity. Prevailing
onshore flow within a zone focused between a broad occluded cyclone
in the Gulf of Alaska and a stout ridge axis focused over the
Southwestern U.S. will lead to a prevailing moderate rain setup over
much of the same areas impacted the previous periods. Total rainfall
in the Northern Cascades over into the Olympic Peninsula will run
between 4-7" with local amounts to 9" possible in the 72 hour time
frame of the AR. The same impact scenarios apply with the focus
being a compounding factor of rainfall, snow melt, and prolonged run
off into local rivers and streams that could result in flooding
prospects for multiple days as river levels reach action stage and
minor to even moderate flood stages. It will be important to
maintain awareness on local river conditions as the additional rain
will exacerbate any receding potential within the river basins.
Highest impacted zone will continue to be the Chehalis River basin
where Flood Watches are in effect even into D3 (see below) due to
the prolonged AR and river levels continuing to run high after
several weeks of rainfall. Additional watches are in effect over the
Northern Cascades due to anticipated run off from rain and snow melt
leading to newer hydro concerns as the event wears on. The previous
MRGL risk inherited was unchanged given the continuity.

Kleebauer


Day 3
Valid 12Z Fri Mar 20 2026 - 12Z Sat Mar 21 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Final day of impact for the current AR event over WA state will
occur within the D3 period with much of any rainfall expected to occur
in the first half Friday before the event finally comes to a close
a strong shortwave trough exits the Pacific with a cold front
passage signaling the end to the threat. Additional 1-2 inches of
rainfall across northwest WA will bring final event totals to the
5-10 inch range over the span of 4 days which will ultimately
contribute to persistent river flood concerns thanks to the snow
melt coupled with rainfall to drain into the basins surrounding the
Olympic Peninsula and Northern Cascades. The last wave of precip
will be relatively heavy compared to the prior period as the
shortwave addition will add a bit more vigor in the ascent pattern
along with IVT and PWAT advection anomalies pushing 3-4 standard
deviations above normal, respectively. Thankfully, this last push
will materialize and end fairly quickly as the fast flow provided
by a stout 165kt upper jet max will advance the final
wave/disturbance eastward into southern British Columbia dragging
the cold front swiftly through the region between 18-00z Fri/Sat.
Flood Watches for the Cascades and portions of the Olympic
Peninsula, with a focus on the Chehalis River remain in effect
until Friday afternoon local time. The previous MRGL risk was
generally unchanged as the pattern remains locked-in across various
guidance.

Kleebauer
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 190700
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
300 AM EDT Thu Mar 19 2026

Day 1
Valid 12Z Thu Mar 19 2026 - 12Z Fri Mar 20 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WESTERN WASHINGTON STATE...

An atmospheric river of moisture and rainfall originating from the
tropics near Hawaii (a.k.a. Pineapple Express) will be directed at
the Olympics and Cascades of western Washington State on Thursday.
The plume will be guided by a large and very anomalously strong
upper level high/ridge over the Southwest, and a series of lows,
both over the Pacific and the Gulf of Alaska. The plume itself will
be anomalous in that the moisture content will be between 3 and 4
sigma above normal for March for western Washington as PWATs exceed an inch.

Heavy rain will impact much of western Washington through the day
on Thursday. A brief diminishing of the rain is expected through
the first half of Thursday night before a weak wave of low pressure
moves into southern British Columbia, and another round of heavier
rain moves in after midnight. Total rainfall amounts will be in the
2-4 inch range in the Olympics and northern Cascades. This rain
will be on top of already saturated soils from prior rain events,
so much of the new rainfall will quickly convert to runoff.
Isolated flash flooding is probable, especially in urban and
flood-prone areas.

Wegman


Day 2
Valid 12Z Fri Mar 20 2026 - 12Z Sat Mar 21 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WESTERN WASHINGTON STATE...

A weak wave of low pressure will move ashore into Vancouver Island
very early Friday morning. The moisture associated with its
trailing front will continue the heavy rain into western Washington
from overnight Thursday night. The low will dissipate in southern
British Columbia during the day Thursday, but the associated
rainfall will likely continue for much of the day Friday. Once the
center of the low reforms over the Plains in Alberta, the flow will
weaken enough to end any upslope into western Washington, and
ending the rainfall event. Nevertheless, expect an additional 1-2
inches of rain into the Olympics and another 2-3 inches into the
Washington Cascades before the rain ends. Given plentiful earlier
rains from Day 1/Thursday, there is some potential for flooding to
be ongoing at the start of the period. In which case, additional
rainfall could worsen ongoing flooding and/or initiate new
flooding. A Slight Risk upgrade could be needed with future updates
in the northern Cascades.

Wegman


Day 3
Valid 12Z Sat Mar 21 2026 - 12Z Sun Mar 22 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 200718
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
318 AM EDT Fri Mar 20 2026

Day 1
Valid 12Z Fri Mar 20 2026 - 12Z Sat Mar 21 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WESTERN WASHINGTON STATE...

At the beginning of the forecast period, a stubborn atmospheric
river is forecast to weaken as a surface low and attendant cold
front progress eastward into the Pacific Northwest. Even so,
moderate IVT values on the order of 500-700 kg/m * s directed into
the WA coastline from 12-18Z should maintain the threat of locally
heavy rainfall ahead of the front. While hourly rainfall rates will
likely remain below 0.5 inches per hour, isolated instances of
excessive rainfall remain possible in upslope regions of the
Olympics and Cascades owing to antecedent rainfall over the last few days.

Asherman


Day 2
Valid 12Z Sat Mar 21 2026 - 12Z Sun Mar 22 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Asherman


Day 3
Valid 12Z Sun Mar 22 2026 - 12Z Mon Mar 23 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Asherman
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 220804
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
404 AM EDT Sun Mar 22 2026

Day 1
Valid 12Z Sun Mar 22 2026 - 12Z Mon Mar 23 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE UPPER
OHIO VALLEY TO THE NEW YORK CITY METRO...

A strong cold front, supported by a passing upper level shortwave,
will press southward from the Great Lakes towards the upper Ohio
Valley and the mid-Atlantic. The warm air mass ahead of the front
is characterized by dew points in the lower 60s across the Ohio
Valley and upper 50s across the mid-Atlantic. These are hardly
great amounts of moisture. Nonetheless, especially over the Ohio
Valley, instability will increase Sunday afternoon to between 1,000
and 2,000 J/kg. This will be enough to support widespread
thunderstorm development ahead of the front. The flow of warm air
will be out of the WSW, essentially parallel to the front. This
will support cells within the SSE-ward moving line moving east,
allowing for some opportunity for some training. The combination of
better upper level support from the aforementioned shortwave,
greater instability, and available moisture will begin to counter
the much drier-than-normal soils and rather fast movement of the
cold front. Organized convection will break out across Pennsylvania
in the late afternoon, then "zip" southwestward across the upper
Ohio Valley during the evening, with storms persisting well into
the overnight hours. The inherited Marginal Risk area was expanded
south and west to include more of southeast Ohio and northern West
Virginia, where the threat for training storms could result in
isolated instances of flash flooding.

Further east, across much of Pennsylvania, wetter-than-normal
soils from recent rains could support enough rainfall from storms
to result in isolated instances of flash flooding. East of the
Appalachians, however, instability rapidly decreases the closer to
the ocean you go. This will result in decreasing rainfall rates for
any storms that move east off the mountains. The front will also
be slower to move south than the same front further east. Thus,
while any rain rates from mostly stratiform precipitation will be
low, a longer period of time of rain along with wetter soils could
also prove enough to result in isolated flash flooding. The
inherited Marginal Risk from central Pennsylvania east to the New
York City Metro is unchanged from inherited.

Wegman


Day 2
Valid 12Z Mon Mar 23 2026 - 12Z Tue Mar 24 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman


Day 3
Valid 12Z Tue Mar 24 2026 - 12Z Wed Mar 25 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Portions of western Washington State, specifically the Olympic and
Cascades Mountains, will be monitored for a potential Marginal
Risk introduction with future updates. A front moving into the area
will make for a brief time (12-hour) of heavy rain Tuesday morning.
While this would normally not be nearly long enough to result in
flash flooding, given there is ongoing river flooding from the last
event, and both soils and streams/creeks are full, this round of
heavy rain may be enough to cause renewed isolated flash flooding.

Wegman
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 230600
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
200 AM EDT Mon Mar 23 2026

Day 1
Valid 12Z Mon Mar 23 2026 - 12Z Tue Mar 24 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman


Day 2
Valid 12Z Tue Mar 24 2026 - 12Z Wed Mar 25 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

...Western Washington State...

Guidance on rainfall amounts with a brief round of heavy rain
Tuesday has not changed appreciably. Low snow levels will allow
much of the expected precipitation to fall as snow. Thus, the area
will be monitored but no Marginal Risk is needed.

...Northeast Florida...

A nearly stationary low off the coast of St. Augustine/Daytona
Beach may support nearly stationary convection forming over/near
I-95 in that area. Any storms that form will be capable of
producing heavy rain. Very dry soils and generally flat, flood-
averse drainage basins are likely to be able to absorb any heavy
rain. The area will continue to be monitored for an eventual
Marginal Risk as stationary storms over a semi-urban area for an
extended period could result in localized flooding/ponding.

Wegman


Day 3
Valid 12Z Wed Mar 25 2026 - 12Z Thu Mar 26 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 240622
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
222 AM EDT Tue Mar 24 2026

Day 1
Valid 12Z Tue Mar 24 2026 - 12Z Wed Mar 25 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman


Day 2
Valid 12Z Wed Mar 25 2026 - 12Z Thu Mar 26 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Wegman


Day 3
Valid 12Z Thu Mar 26 2026 - 12Z Fri Mar 27 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MIDWEST AND OHIO VALLEY...

A strong cold front will move southward across the Midwest Thursday
night. The front will run into a marginally unstable and warm air
mass, but with limited moisture with surface dew points on either
side of 60 degrees. Nonetheless, with some upper level support and
significant shear, organized thunderstorms are likely to form
Thursday evening. The storms could then train over many of the
same areas that saw some heavy rain from a very similar-behaving
front yesterday. This is a lower-end Marginal Risk as upper level
support and instability will both not be quite as favorable to the
storms as yesterday. This will be somewhat offset by a bit wetter
soils by then than they were before yesterday's rainfall event. The
areas most likely to see an instance or two of flash flooding are
the urban centers. Should forecast rainfall decrease, which appears
possible, the Marginal may be able to be dropped with future
updates.


Wegman
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 281515
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1115 AM EDT Sat Mar 28 2026

Day 1
Valid 16Z Sat Mar 28 2026 - 12Z Sun Mar 29 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

...16Z Update...

No changes were needed with the blank outlook for the rest of today
and tonight. In coordination with MFL/Miami, FL forecast office,
there was agreement that the flooding threat in south Florida
remains sub-Marginal. The CAMs are in good agreement that any
convection that forms today will develop west of the urban I-95
corridor, then track southwest across relatively rural areas around
Lake Okeechobee and into the Everglades and the Naples/Marco
Island area. This should preclude any flooding concerns, especially
given the ongoing drought and below average soil moisture levels
broadly across south Florida.

Wegman

...Previous Discussion...

We will keep an eye on south FL, where convection is likely this
afternoon into tonight. However, at this time the flash flood risk
looks low. Initial convective development along the east coast of
FL should move off to the southwest, limiting rainfall rate
duration. Additional development this evening into tonight near and
post frontal passage should generally stay transient in nature,
with a downward trend in CAPE also expected overnight.

The 00z HREF and REFS neighborhood probabilities of exceeding 3"
are over 50%, but generally focused over inland areas of south
FL...and 5" exceedance probabilities from the HREF are zero. For a
Marginal risk we would like to see the higher 3" probabilities
focused across the coastal urban areas and/or significantly higher
5" probabilities. Thus will continue with no risk area.

Chenard


Day 2
Valid 12Z Sun Mar 29 2026 - 12Z Mon Mar 30 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Additional showers and thunderstorms are expected across southeast
FL, with a stream of activity potentially focused near the urban
corridor. However, most model instability forecasts are below 1000
j/kg, and thus currently not expecting rainfall rates to be high
enough for flash flooding, but we will continue to monitor.

Chenard


Day 3
Valid 12Z Mon Mar 30 2026 - 12Z Tue Mar 31 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

There is a non-zero risk for minor urban and small stream flooding
across portions of MI, northwest PA and western NY Monday into
Monday night. There is a notable increase in instability, with
values exceeding 1000 j/kg. This is anomalous for the time of
year, especially over portions of MI where the ECMWF EFI for CAPE
is over 0.9. Combine this CAPE with above average PWs and strong
moisture transport and we would expect there to be a potential for
heavy rainfall rates. At the moment, not really seeing enough of a
consistent model QPF signal to justify introducing a risk area, but
we will have to continue to monitor trends, especially as we move
more into the high res model timeframe.

Chenard
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 290820
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
420 AM EDT Sun Mar 29 2026

Day 1
Valid 12Z Sun Mar 29 2026 - 12Z Mon Mar 30 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Chenard


Day 2
Valid 12Z Mon Mar 30 2026 - 12Z Tue Mar 31 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

An uptick in convective activity is expected Monday night into
Tuesday morning across portions of MI into western PA/NY. There is
a strong surge of moisture and instability, and thus locally heavy
rainfall is possible. Overall it seems like the better chance of
localized flash flooding is after 12z Tuesday as the duration of
rain makes hydrologic conditions more sensitive by then. So we
will hold off on introducing any day 2 risk area and let the day 3
Marginal cover the threat. But we will continue to monitor trends
as the event gets more in range of the high res models today.

Chenard


Day 3
Valid 12Z Tue Mar 31 2026 - 12Z Wed Apr 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE OHIO VALLEY INTO NEW YORK AND VERMONT...

A stationary front positioned over NY will likely be a focus for
scattered convection to start the period Tuesday morning. The
front is not forecast to move much during the day, likely
supporting periodic rounds of scattered showers and thunderstorms.
An area of low pressure riding along the front should increase
forcing and convergence by Tuesday evening, resulting in an uptick
in rainfall coverage.

Moisture parameters are impressive with this system...PWs are
forecast to be near late March to early April max values, and IVT
increases above the climatological 90th percentile. Instability is
more marginal, and will likely reduce max rainfall rate potential
and act as a limiting factor for flash flooding. However, there is
some instability forecast in the morning, and by evening the
increasing forcing/convergence could help offset decreasing
instability. Thus while not widespread, some localized hourly
rainfall around 1" seems plausible.

Model consensus rainfall magnitudes are generally in the 1-2"
range, although with multiple rounds likely, there is a potential
for more localized swaths getting into the 2-4" range. These
higher amounts are most likely over portions of far northeast OH,
far northwest PA and into southwest NY...near the stationary front
and within a corridor where instability has a better chance of
persisting. A bit farther northeast into upstate NY and VT, some
snow melt contribution could also aid in minor runoff concerns.
Farther southwest over IN and OH instability is higher supporting
greater rainfall rates, but duration should be shorter with a
quicker frontal progression. Soil and streamflow conditions are
more conducive for flood impacts over portions of OH and IN, but
dry out with southwest extent into IL and MO. Thus while convection
will extend into these latter areas as well, for now we will stop
the Marginal risk near the IL/IN border.

Overall the primary threat is for localized flooding in areas
where training, or multiple convective rounds, occur near the
stationary front...or where higher short duration rates intersect
sensitive urban areas.

Chenard

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 300852
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
452 AM EDT Mon Mar 30 2026

Day 1
Valid 12Z Mon Mar 30 2026 - 12Z Tue Mar 31 2026

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

While the better setup for localized flash flooding occurs after
12Z, there will be the presence of an increasing surge of moisture
and instability leading to the potential for localized heavy rainfall.

Campbell


Day 2
Valid 12Z Tue Mar 31 2026 - 12Z Wed Apr 01 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE GREAT LAKES INTO NORTHERN NEW ENGLAND...

The latest guidance has continued to see an uptick in forecast
amounts across the lower Great lakes and New England regions for
this period. Impressive moisture advection characterized by IVT
values exceeding 750 kg/ms in spots will move northeast along a
slow-moving front across the Great Lakes. This will allow near
record amounts of atmospheric moisture for this time of year, with
PWATs exceeding 1.25 inches at times to move into the Marginal Risk
area. Instability will increase towards the south and west, but
drier antecedent soil conditions and weaker forcing should cancel
out those supporting meteorological factors along the Mississippi
River and the Ozarks. During this period a stationary front draped
across New York remain in place, providing focus for rounds of scattered convection to fire up. By Tuesday evening rainfall coverage should
increase as an area of low pressure tracks along the frontal
boundary. Guidance continues to favor areal averages of 1-2 inches
for the region, however with training possible, localized higher
amounts of 2-4 inches may materialize over the northeast Ohio, far
northwest PA and into southwest NY...near the stationary front and
within a corridor where instability has a better chance of persisting.

Campbell/Chenard


Day 3
Valid 12Z Wed Apr 01 2026 - 12Z Thu Apr 02 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL STRETCHING FROM
TEXAS TO THE MIDWEST/UPPER MIDWEST...

The central portion of the country is shaping up for heavy rainfall
as a frontal system extending from the Northeast to the Mid-South
taps into Gulf moisture advecting northward. Multiple rounds of convection
are expected to fire up across central and eastern CONUS given the
upper level support for sustained rainfall potential. Local
flooding may arise over portions of the Southern Plains, Lower and Mid-Mississippi Valley. The general footprint of the rainfall
shield has trended a bit west from the previous cycle thus
requiring a western adjustment of the Marginal Risk area.
Consensus continues to favor the highest QPF to focus over eastern
Oklahoma, southeast Kansas and into central Missouri.

The timing of the incoming shortwave/lifting warm front has
remained a trickier part of the forecast, and convection south
along the cold front may also limit instability further
north/become the higher threat. At this time a Slight Risk was not
raised but may be needed with future updates.

Campbell/Tate
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 310757
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
357 AM EDT Tue Mar 31 2026

Day 1
Valid 12Z Tue Mar 31 2026 - 12Z Wed Apr 01 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
WESTERN NEW YORK AND SOUTHEAST MICHIGAN...

Overall upper pattern will become slowly backed as a deep longwave
trough out west begins to pump the mid-level ridge downstream from
the Mississippi River to the eastern CONUS. At the surface, a
quasi-stationary front will bisect areas west to east from the
Midwest the Northeast with a weak surface low migrating along the
frontal positioning. Shortwave associated with the area of low
pressure will eject through the Great Lakes leading to a period of
convective development downstream into Michigan and points east.
This initial round is expected to occur early in the period,
producing moderate to locally heavy amounts across southeast
Michigan and to the favored downwind locations of Lake Erie. The
extra enhancement from Lake Erie should boost rainfall closer to 2 inches.

As the morning progresses, the low will migrate into Ontario and
the frontal boundary will drop southward toward the Ohio Valley. A
second shortwave is set to eject and usher in another round of
convection for the northern Missouri Valley. PW values will be
increasing which should boost rainfall rates to 1-1.5 inches/hour.
These two rounds of heavy rain for western New York areas downwind
of Lake Erie will see widespread totals of 1.5-3" leading to a
more elevated flash flood concerns, especially when combined with
river flood concerns as stream flows across the region have been
elevated since the previous events over the area. Flood Watches
will be in effect for portions of western NY given the signal of
both the river and flash flood threat aligning well with a targeted
SLGT risk across the area.

The Slight Risk extends back into Detroit due to the urbanization
factors and expected heavy rainfall the front half the period into
the metro which creates a better opportunity for flash flooding
considering the setup. A Marginal Risk encompasses the
northeastern portion of Illinois through southern Michigan,
northern Indiana/Ohio, and extends well east and northeast to
include Upstate New York, Northern New England, and the northern
Hudson Valley as combination rainfall and snow melt will allow for
elevated stream flows and any locally heavy rainfall could induce
flash flood prospects.

Campbell/Kleebauer


Day 2
Valid 12Z Wed Apr 01 2026 - 12Z Thu Apr 02 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL STRETCHING FROM
EASTERN KANSAS INTO SOUTHEAST IOWA...

The latest guidance continued to trend westward with the overall QPF
footprint however maintained consensus for the heaviest amounts to
focus from eastern Kansas to the Missouri/Iowa border. A long axis
of convection is expected from Texas into the Mid/Upper Mississippi
Valley. A prominent warm-sector will materialize from west-
central Texas into Missouri with a surface low forecast to be
positioned over the Central Plains by Wednesday afternoon. Several
shortwaves will eject northeast within and ahead of the mean
trough leading to multiple waves of rainfall across parts of Kansas
into Missouri. Multiple waves of heavier rain could impact the
area. Despite the antecedent dry conditions in place, prolonged
rainfall within the urban corridor with slower cell motions could
lead to a greater threat for scattered flash flooding before the
system finally moves eastward and the area sees the frontal
passage. Areal averages of 1.5-2.5 inches are forecast however
there is potential for isolated higher amounts of 3+ inches. A
Marginal Risk area spans from central Texas to the Illinois/Indiana
border. A Slight Risk area was hoisted for eastern Kansas,
western/northern Missouri and southeast Iowa.

Campbell/Kleebauer


Day 3
Valid 12Z Thu Apr 02 2026 - 12Z Fri Apr 03 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
ILLINOIS, WISCONSIN AND LOWER MICHIGAN...

By this period the surface low pressure/frontal system will stretch
from the Mid-Atlantic back into the Ohio and Mid-Mississippi
Valleys. Models have trended further north with the overall
precipitation shield, now covering much of the Upper Great
Lakes/Upper Midwest region. The moisture and instability along
with the upper-level support could lead to flooding concerns across
parts of the Great Lakes region. Colder air filtering across the
northern tier will allow for wintry weather concerns in the Great
Lakes to Interior Northeast thus limiting the area where flash
flooding may occur/cause impacts. A swath of potentially impactful
freezing rain/ice along with multiple inches of April snow, with
the heaviest snow currently forecast in the U.P. of Michigan into
northern Maine. Some areas could see transitioning precipitation
types throughout the event. A Marginal Risk area is in effect for
portions of southern Wisconsin, Lower Michigan and northern Illinois.

Campbell
$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 010803
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
403 AM EDT Wed Apr 1 2026

Day 1
Valid 12Z Wed Apr 01 2026 - 12Z Thu Apr 02 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL STRETCHING FROM
CENTRAL OKLAHOMA INTO NORTHERN MISSOURI...

The latest hi-res and global guidance noted a south/southwest-ward
shift of the axis of highest precipitation to central Oklahoma to
northern Missouri from its previous position of northeast Kansas
into east-central Iowa where areal averages of 1 to 3 inches are
expected. There remains a decent signal for localized 3+ inches in
the vicinity of the Topeka-Kansas City metros. The Slight Risk
area was adjusted to now cover eastern Oklahoma to northern
Missouri while the Marginal Risk was maintained from the Texas
Hill Country to the Mississippi/Ohio Valleys.

A prominent warm-sector will materialize from west-central Texas
into Missouri with a surface low forecast to be positioned over the
Central Plains by Wednesday afternoon. Several shortwaves will
eject northeast within and ahead of the mean trough leading to
multiple waves of rainfall from the south-central Plains into the
Middle Mississippi Valley. Some training potential, leading to 1-3
inch areal average amounts in this region, with some potential for
isolated higher amounts of 3+ inches. Farther south, a long axis
of convection is expected from Texas to Kansas along the cold
front, but storms in this area should be more progressive and soils
are even more dry than to the north.

Campbell/Santorelli


Day 2
Valid 12Z Thu Apr 02 2026 - 12Z Fri Apr 03 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN IOWA, NORTHERN ILLINOIS, WISCONSIN AND MICHIGAN...

The front will span from the Mid-Atlantic back into the Ohio and Mid-Mississippi Valleys during this period. Models have persisted
in placing the precipitation shield over much of the Upper Great
Lakes/Upper Midwest region. The moisture and instability along with
the upper-level support could lead to flooding concerns across
parts of the Great Lakes region. Colder air filtering across the
northern tier will allow for wintry weather concerns in the Great
Lakes to Interior Northeast thus limiting the area where flash
flooding may occur/cause impacts. Some areas could see
transitioning precipitation types throughout the event. A Marginal
Risk area remains in effect for portions of southern Wisconsin,
Lower Michigan and northern Illinois where precipitation is most
likely to stay mostly/all rain.

Campbell/Santorelli


Day 3
Valid 12Z Fri Apr 03 2026 - 12Z Sat Apr 04 2026

...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHERN/CENTRAL PLAINS...

Strong to severe thunderstorms along with embedded heavy rainfall
will track across the Southern/Central Plains into the Midwest
during this period. Moisture (with PWs over the 90th, perhaps 95th
percentile) and instability are likely to pool along and ahead of
the associated cold front and produce widespread convection.
Storms likely beginning in the afternoon are expected to get
reinforced through the evening and night hours as a low level jet
picks up ahead of the cold front. A Slight Risk was maintained and
adjusted to span from northern Texas to southwest Missouri.

Campbell

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)

FOUS30 KWBC 011552
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1152 AM EDT Wed Apr 1 2026

Day 1
Valid 16Z Wed Apr 01 2026 - 12Z Thu Apr 02 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL STRETCHING FROM
CENTRAL OKLAHOMA INTO NORTHERN MISSOURI AND THE CONCHO VALLEY...

...Central to Southern Plains...

16Z Update: The previous forecast remains on track with a heavy QPF
signature focused within the warm sector of a maturing synoptic
pattern as a lee surface low migrates eastward through the Central
Plains. Latest 12z HREF neighborhood probabilities for >3" remain
very elevated (50-70%) across areas of southeast KS up into
west-central MO, coincident with the axis of greatest convergence
where a propagating cold front will couple with a budding LLJ and
maximized mid-level forcing to create a solid area of heavy
convection beginning this afternoon, carrying through the overnight
hours. Heavy rain signature remains most prominent between the
quadrant of I-35/44/49/70 with portions of both the Wichita and
Kansas City metros in mix for heavy precipitation. Backed flow for
a time across zone will allow for some training elements prior to
the precip field migrating east-northeastward as a frontal passage
finally puts an end to the setup. Overall, this setup has
relatively good continuity in guidance going back to a few days
ago, thus only minor adjustments were made to the overall SLGT risk
area with the "biggest" change being more of an extension eastward
through MO for areas along and north of I-70 to correlate with some
overlap of heavy precipitation over areas that saw heavy rainfall
the past 12hrs.

Kleebauer

..Previous Forecast Discussion..

The latest hi-res and global guidance noted a south/southwest-ward
shift of the axis of highest precipitation to central Oklahoma to
northern Missouri from its previous position of northeast Kansas
into east-central Iowa where areal averages of 1 to 3 inches are
expected. There remains a decent signal for localized 3+ inches in
the vicinity of the Topeka-Kansas City metros. The Slight Risk
area was adjusted to now cover eastern Oklahoma to northern
Missouri while the Marginal Risk was maintained from the Texas
Hill Country to the Mississippi/Ohio Valleys.

A prominent warm-sector will materialize from west-central Texas
into Missouri with a surface low forecast to be positioned over the
Central Plains by Wednesday afternoon. Several shortwaves will
eject northeast within and ahead of the mean trough leading to
multiple waves of rainfall from the south-central Plains into the
Middle Mississippi Valley. Some training potential, leading to 1-3
inch areal average amounts in this region, with some potential for
isolated higher amounts of 3+ inches. Farther south, a long axis
of convection is expected from Texas to Kansas along the cold
front, but storms in this area should be more progressive and soils
are even more dry than to the north.

Campbell/Santorelli

...Texas...

A SLGT risk was added across the Concho Valley in west TX as trends
for back-building convection along a well-established dryline will
open the door for heavy precipitation totals where training
convection is plausible. Recent HREF QPF trends were pretty
substantial in the last few cycles of the hi-res ensemble with the
blended mean QPF a solid 2-3" across the area between the Lower
Trans Pecos and points east-northeast to the northern fringes of
Hill Country. A lot of this setup stems from a sharpening dryline
that tilts back to the west-southwest as a maturing nocturnal LLJ
takes shape after 23z. Convergent signature within a favorably
unstable environment and stout 45-55kt bulk shear axis should allow
for the initiation of supercellular convective modes the first 2-4
hrs of any development followed by an eventual merger of cells as
the LLJ matures further. This is a classic scenario of the southern
edge of a larger ascent pattern in spring that tends to be more
appreciable for heavy rainfall with the dryline and LLJ convergence
zone becoming the focal point for where the higher QPF concerns
arise. Latest HREF neighborhood probabilities for >3" of rainfall
are between 40-60% with the bullseye centered over the Concho
Valley, including the San Angelo area where terrain and
urbanization factors lend credence to a better localized flash
flood risk for the area of interest. Hourly rate probabilities for

1"/hr are very high (50-70%) for several hours across the same

area(s) which will be the driving force for the entire setup. In
coordination with the local San Angelo WFO, the SLGT risk was added
due to the evolving threat.

Kleebauer


Day 2
Valid 12Z Thu Apr 02 2026 - 12Z Fri Apr 03 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN IOWA, NORTHERN ILLINOIS, WISCONSIN AND MICHIGAN...

The front will span from the Mid-Atlantic back into the Ohio and Mid-Mississippi Valleys during this period. Models have persisted
in placing the precipitation shield over much of the Upper Great
Lakes/Upper Midwest region. The moisture and instability along with
the upper-level support could lead to flooding concerns across
parts of the Great Lakes region. Colder air filtering across the
northern tier will allow for wintry weather concerns in the Great
Lakes to Interior Northeast thus limiting the area where flash
flooding may occur/cause impacts. Some areas could see
transitioning precipitation types throughout the event. A Marginal
Risk area remains in effect for portions of southern Wisconsin,
Lower Michigan and northern Illinois where precipitation is most
likely to stay mostly/all rain.

Campbell/Santorelli


Day 3
Valid 12Z Fri Apr 03 2026 - 12Z Sat Apr 04 2026

...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHERN/CENTRAL PLAINS...

Strong to severe thunderstorms along with embedded heavy rainfall
will track across the Southern/Central Plains into the Midwest
during this period. Moisture (with PWs over the 90th, perhaps 95th
percentile) and instability are likely to pool along and ahead of
the associated cold front and produce widespread convection.
Storms likely beginning in the afternoon are expected to get
reinforced through the evening and night hours as a low level jet
picks up ahead of the cold front. A Slight Risk was maintained and
adjusted to span from northern Texas to southwest Missouri.

Campbell

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/10)