FOUS30 KWBC 180834
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
434 AM EDT Sat Jul 18 2026

Day 1 Valid 12Z Sat Jul 18 2026 - 12Z Sun Jul 19 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHWEST, GREAT BASIN, WEST TEXAS, AND THE NORTHEAST...

...Western Texas to the Four Corners/Great Basin...
Overall, the forecast remains much the same, with mostly minor
spatial adjustments required based on the latest hi-res ensemble guidance.

One of the bigger adjustments was a northward extension
of the Slight Risk across western Texas into the southern
Panhandle. This northern expansion was supported by a slow-moving
upper level shear axis combined with low-level southerly flow,
fueling notable moisture advection into that region. Both the HREF
and REFS guidance have trended more bullish, showing localized
potential for rainfall amounts exceeding 3 inches. These totals
will be capable of producing rapid runoff and localized flash
flooding, especially where soil conditions are more sensitive from
recent rainfall.

Farther west, the Slight Risk remains largely unchanged across
portions of New Mexico, Arizona, southern Utah, and southwestern
Colorado. This remains supported by high-moisture anomalies and
indication from the HREF and REFS for rainfall rates likely to
reach at least 0.5 in/hr in the stronger cells. The Mogollon Rim
looks to remain a focus storm initiation and for some of the higher
storm totals, with both the HREF and REFS showing high
probabilities for accumulations over 2 inches in that area. Recent
heavy rains across this area will likely make it more susceptible
to additional flash flooding.

...Midwest to the Mid Atlantic and Northeast...
A progressive cold front dropping southeastward is expected to
interact with an anomalously moist airmass pooling ahead it. While
the primary Slight Risk remains focused across parts of the
northern Mid Atlantic to southern New England, the broad western
shield of the Marginal Risk was expanded farther west across the
Ohio Valley and into northern Illinois. Within this area, a smaller
Slight Risk area was added over portions western Pennsylvania
where the latest HREF and REFS are indicating localized amounts of
2-3 inches are likely.

For the Slight Risk area over the northern Mid Atlantic and
Northeast, guidance shows two rounds of storms impacting portions
of eastern Pennsylvania, New Jersey eastward to southern New
England. A leading round of storms, well in advance of the front,
is expected to impact the region this afternoon, followed by a second
round accompanying the front itself during the overnight. Many of
the hi-res members suggest the heavier rainfall and potential flash
flooding threat will accompany the initial round, with the loss of
daytime heating and more stable air limiting the threat with the
second. With at least the first round, highly-efficient warm rain
processes and localized cell training may yield quick, short-
duration totals capable of producing isolated to scattered runoff
concerns, particularly in low-lying or urbanized areas. The Slight
Risk largely reflects the higher HREF probabilities for
accumulations of 3 inches or more.

...Florida Panhandle into Southeast Alabama and Southwest Georgia...
Deep moisture spreading north ahead of a slow-moving mid-to-upper
level low will pool along a surface trough extending out of the
eastern Gulf. This moisture (PWs increasing to around 2 inches)
will fuel slow-moving storms developing by the late afternoon that
will be capable of producing heavy rates, which along with their
slow movement, may produce heavy amounts and isolated flash
flooding.

Pereira


Day 2 Valid 12Z Sun Jul 19 2026 - 12Z Mon Jul 20 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS THE
SOUTHWESTERN U.S. FROM WEST TEXAS TO SOUTHERN UTAH...

...Southwestern U.S....
The overall synoptic configuration remains largely unchanged from
the previous period, with a persistent monsoon pattern locked in
place -- keeping scattered to widespread convection in the forecast
from West Texas into the Great Basin and southern Rockies. Given
that PW anomalies remain notably high at 2-3 std dev above normal,
and soil conditions moist from prior rainfall, confidence was
sufficient to introduce a Slight Risk that extends from West Texas northeastward across southern New Mexico, central and northern
Arizona, into southern Utah.

An upper-level high centered over northern Utah and Colorado will
support steady easterly flow across the southern tier, effectively
tapping into and beginning to pull mid-level energy that has been
centered over West Texas along this deeper moisture axis. The
highest areal average precipitation amounts are expected to center
along the higher terrain, where slow-moving storms are expected to
develop with afternoon heating, before propagating off of the
terrain along convective outflows. Given sensitive, moist soil
conditions from successive days of widespread storms, much of this
area remains vulnerable to rapid runoff. Complex terrain, slot
canyons, and recent wildfire burn scars will further accentuate the
threat for flash flooding across parts of the region.

...Mid Mississippi Valley east to the Carolinas and south to the
Eastern Gulf Coast...
A more expansive Marginal Risk has been drawn for this period,
reflecting deep moisture atmospheric profiles and an increasing
potential for localized heavy rainfall amounts producing isolated
runoff concerns. This risk is centered along a cold front dropping
into North Carolina and the Tennessee Valley, while is begins to
slow over the lower Ohio and mid Mississippi valleys. Diurnal
heating and prefrontal convergence will tap into this moisture
pool, generating clusters of slow-moving efficient thunderstorms,
capable of producing 1-2 inch totals, with isolated higher amounts.
There remains a greater threat for more widespread heavier amounts
along the eastern extent of this area, centered over southeastern
Virginia and eastern North Carolina, where more defined upper
forcing will help accentuate the threat for amounts over 3 inches.

Additionally, the Marginal Risk has been extended southward down to
the Gulf Coast. This accounts for the deep tropical moisture
arriving ahead of the slow-moving disturbance lingering in the
eastern Gulf, as well as favorable low-level convergence focusing
along a slow-moving surface trough extending north from the Gulf.
Highly efficient warm-rain processes along these features will
maintain a threat for heavy, short-term duration totals and
isolated runoff concerns.

Pereira
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 190921
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
521 AM EDT Sun Jul 19 2026

Day 1 Valid 12Z Sun Jul 19 2026 - 12Z Mon Jul 20 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE SOUTHWESTERN U.S. FROM WEST TEXAS TO SOUTHERN UTAH, AS WELL AS
EASTERN NORTH CAROLINA AND THE VIRGINIA TIDEWATER REGION...

...Southwestern U.S....
Overall, the synoptic pattern remains much the same, with the
monsoon ridge remaining favorably aligned. PW anomalies of 2-3 std
dev above normal will remain across much of the highlighted area.
This moisture, along with sufficient instability, and areas of
enhanced ascent afforded by easterly-drifting mid-level energy.
will support another day of widespread convective activity. Slow-
storm motions along with likely cell-mergers will raise the threat
for locally heavy amounts and flash flooding concerns. Flash
flooding remains a distinct threat in slot canyons, dry washes,
burn scars, and low desert areas via mountain outflows. The Slight
Risk highlights the area where HREF and REFS guidance indicate the
threat for 1-2 inch amounts is greatest. The REFS, and to a lesser
extend the HREF, indicate that heavier totals of 3+ inches are
possible over portions of West Texas along the Mogollon Rim down
into southeastern Arizona.

...Lower Missouri Valley to Southeastern Virginia and Eastern North Carolina... A targeted Slight Risk remains centered over eastern North
Carolina and extends into southeastern Virginia. Convection will
develop ahead of a slow-moving cold front that will be dropping
into a very moist (PWs 2+ inches) and unstable (MUCAPE > 2000
J/kg) environment, while some modest right-entrance region upper
jet forcing will offer some enhanced ascent. Heavy totals appear
likely, with both the HREF and REFS showing high neighborhood
probabilities for amounts over 3 inches within the Slight Risk area.

Less organized activity is expected back along the front extending
across the southern Appalachians, Tennessee Valley, and parts of
the lower Ohio, mid Mississippi, and lower Missouri valleys. While
widespread heavy totals are not expected, the moisture-rich
environment (PWs 1.75-2 inches) is expected to support storms
capable of producing localized heavy amounts and isolated runoff concerns.

...Eastern Dakotas into the upper Mississippi Valley...
A shortwave moving off of the top of the western U.S. ridge will
interact with a frontal system advancing through the northern
Plains into the Upper Midwest. An amplifying west-southwesterly
low level jet will support increasing PWs (1.75-2 inches) and
instability east of a warm front. The overnight guidance differed
greatly on the details but continued to present some signal for
backbuilding and training storms, capable of producing locally
heavy rates within the area highlighted by the Marginal Risk.

...Eastern Gulf Coast into the Southeast...
An area of low pressure located over the northeastern Gulf is
gradually becoming better defined, with additional development
becoming more likely. The footprint for heavy amounts through early
Monday is expected to remain mostly offshore, although some
heavier amounts along the immediate Florida Gulf Coast cannot be
ruled out. Therefore, the Marginal Risk was maintained.

An axis of enhanced low level convergence and pooling moisture to
the north is still expected be a focus for diurnal storms capable
of producing heavy rates. Therefore, a Marginal Risk was maintained
from the central Gulf Coast northward into the Tennessee Valley.
HREF and REFS indicate localized totals exceeding 2 inches are
likely along this corridor.

Pereira


Day 2 Valid 12Z Mon Jul 20 2026 - 12Z Tue Jul 21 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
WEST TEXAS, NEW MEXICO, AND ARIZONA...

...Southwest and Great Basin...
Mid-level energy moving west of the region, and dry air advection
from the south will begin to diminish the heavy rainfall and flash
flooding threat over West Texas. However farther west, the
monsoonal moisture plume will remain firmly in place, ensuring
another day of high-efficient rainfall production over portions of
the Southwest and Great Basin.

Models show the upper high originally centered over Utah and
Colorado beginning to slide southeast, allowing moisture and
energy to spread northwest into the Great Basin and along the
western slopes of the Sierra Nevada -- raising the potential for
increasing storm activity and isolated runoff concerns in those area.

The greater heavy rainfall and flash flooding threat will remain
focused from southwestern New Mexico and southeastern Arizona
northwestward along the Mogollon Rim into northwestern Arizona.
This is expected to be the focus for better synoptic forcing and
greater instability -- supporting intense short-duration rain rates
that will elevate the risk for flash flooding, especially in areas
of complex terrain, dry washes, and burn scars.

...Upper Great Lakes...
An amplifying upper trough supported by energy diving out of
Canada will advance from the upper Mississippi Valley to the upper
Great Lakes. Strong southwesterly to west-southwesterly low level
inflow will continue to sustain deep moisture ahead of the cold
front and across the advancing warm front. This moisture along with
strong forcing, produced in part by left-exit region upper jet
dynamics, will generate organized convection capable of producing
rainfall rates of 1-2 in/hr. Fast storm motions should limit the
overall heavy accumulation and flash flooding threat. However,
localized short-term training could raise at least some isolated concerns.

...North Carolina and Southern Virginia...
Maintained a Marginal Risk across this area. Apart from the GFS and
REFS, the general model consensus indicates that activity will be
less organized. However, a lingering boundary and corresponding
pool of deep moisture (PWs 2+ inches) will support additional
storms capable of producing heavy downpours. Should the guidance
begin to trend more toward the GFS and REFS, a targeted upgrade
may required, especially if more models begin to show back-to-back
days of overlapping heavy amounts.

...Gulf Coast...
The models continue to show the footprint of the heaviest amounts
associated with the disturbance over the northern Gulf remaining
mostly offshore. Therefore maintained only a Marginal Risk along
the coast from West Florida to southeastern Louisiana. Moisture
pooling along an axis of enhanced low level convergence northwest
of the circulation may extend the threat for heavy rainfall further
inland into the far lower Mississippi Valley.

Pereira
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 200827
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Mon Jul 20 2026

Day 1 Valid 12Z Mon Jul 20 2026 - 12Z Tue Jul 21 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
SOUTHWEST AS WELL AS FOR EASTERN NORTH CAROLINA...

...Southwest...

Very few changes were needed with the inherited Slight Risk area
from far west Texas, southwestern New Mexico, and much of Arizona
with this update. Monsoonal moisture will stream north off the Gulf
of California and into the Four Corners region today. With peak
heating, afternoon thunderstorms are expected over much of the
Slight Risk area. Much of the area has seen afternoon thunderstorms
causing localized flash flooding in recent days, and the same
pattern continues today. The threat further east will be driven by
a subtle shortwave disturbance retrograding west along the Mexican
border. This will allow for greater longitudinal spread of storms
to include far west Texas. MUCAPE values will be between 1,000 and
2,000 J/kg across much of the region, as PWATs rise above 1.5
inches in some areas. Between the aforementioned disturbance and
local topography, expect widely scattered instances of flash
flooding where the storms today are most persistent.

...Eastern North Carolina...

A stalled out front along the VA/NC border at the start of the day
will retreat northward in the form of a warm front as deep tropical
moisture advects northeastward from the tropical depression in the
Gulf. The front will provide enough forcing across much of eastern
North Carolina to allow for a renewed round of widespread showers
and thunderstorms in the area. Soils remain generally dry over most
of the area, despite storms impacting some of eastern North
Carolina yesterday. Due to the well above normal amounts of
moisture for the storms to work with, as well as the front
providing some forcing, the Slight Risk was expanded west to
overlap some of the areas of North Carolina that are being impacted
by storms currently, generally just east of Charlotte. Otherwise,
the threat remains similar to yesterday, so few changes were needed
with this update.

...Gulf Coast...

The outermost northern and western periphery of Tropical Depression
Two continues to impact much of the Gulf Coast of Florida, through
the Panhandle, and over to southeastern Louisiana. The storms are
few and far between, but ample moisture associated with a
developing tropical cyclone is allowing for any storms to have the
potential to produce multiple inch per hour rates. Regardless, the
center remains far enough offshore, with drier air aloft working to significantly cut down on the overall coverage of storms.
Considering the dry soils and high FFGs typical of the immediate
Gulf Coast, even periods of heavy rain should only result in
isolated instances of flash flooding. Thus, the inherited Marginal
remains in place.

...Midwest...

The Marginal Risk across much of the Midwest and upper Great Lakes
also remains largely the same today. There remains considerable
uncertainty as to coverage of storms impacting the area today into
tonight. It appears the most likely areas to be impacted stretches
from the southeastern corner of Minnesota south through eastern
Iowa and into northeastern Missouri. However, even in this area,
dry soils and the height of the growing season should allow most of
the rain expected to water the crops in the region, with minimal
threat for flash flooding. Thus, few changes were needed with this update.

Wegman


Day 2 Valid 12Z Tue Jul 21 2026 - 12Z Wed Jul 22 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
ARIZONA AND UTAH, AS WELL AS THE UPPER OHIO VALLEY AND INTO THE
MID-ATLANTIC...

...Arizona into Utah...

Increasing monsoonal moisture, particularly into southern Arizona
will combine with an approaching upper level shortwave trough to
further increase convective converage across portions of the
Southwest on Tuesday as compared with previous days. The
introduction of a northwestward-moving shortwave trough will allow
the convective activity to wane over eastern New Mexico and west
Texas, and instead promote more activity into eastern Nevada, Utah,
and portions of Colorado and Wyoming. Numerous highly flash-flood
prone slot canyons, dry washes, and rocky soils will allow the many
storms that form over the region to cause scattered instances of
flash flooding. The Slight Risk area was expanded north to include
much of Utah and into eastern Nevada for this region. The greatest
convective coverage and most impactful flash flooding is expected
over portions of Arizona and the boot heel of New Mexico. A
higher-end Slight remains in effect along the Mogollon Rim, but has
been expanded to the Mexico border along the AZ/NM border with this update.

...Upper Ohio Valley through the Mid-Atlantic...

A strong cold front pushing south across the Midwest will run into
plentiful tropical moisture being drawn north from Tropical
Depression 2 in the Gulf. The front will act as a catalyst for
numerous segments of mostly fast moving thunderstorms across the
Mid-Atlantic and Ohio Valley on Tuesday. With PWATs ahead of the
front over 2.25 inches in some instances, and in most areas above 2
inches, the storms will have plentiful juice to work with, allowing
for heavy rainfall to impact most areas from the central and
northern Appalachians to the urban I-95 corridor from Richmond up
through Boston. The fast moving nature of the storms should mean
most areas have severe concerns as higher priority than flash
flooding. However, it's likely that backbuilding and training
storms on the book ends of any segments could cause widely
scattered instances of flash flooding. Thus, the Slight Risk
inherited over much of the Mid-Atlantic remains in place with few changes.

...Gulf Coast...

Tropical Depression 2 is expected to gradually drift west, with the
center following near the Gulf Coast. All of the guidance suggests
that northerly shear and dry air entrainment will push any
meaningful associated heavy rainfall south of the center over the
Gulf, leaving very little rainfall to impact the immediate Gulf
Coast. Thus, despite being a tropical cyclone with local PWATs up
to 2.5 inches, the distinctive lack of rainfall for most land
areas, especially away from the immediate coast remains an unusual
feature with TD2. The Marginal Risk in place over most of the
northern Gulf Coast from the Florida Panhandle west through
southeast Louisiana remains in place with few changes.

Wegman
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 210847
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
447 AM EDT Tue Jul 21 2026

Day 1 Valid 12Z Tue Jul 21 2026 - 12Z Wed Jul 22 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
SOUTHWEST AND GREAT BASIN AS WELL AS FOR PORTIONS OF THE OHIO AND
TENNESSEE VALLEYS AND INTO THE NORTHEAST...

...Southwest and Great Basin...

The combination of anomalous monsoonal moisture streaming northward
out of the tropical Pacific and a retrograding upper level
shortwave will create a very active day for thunderstorm activity
this afternoon across much of the Pacific Northwest. Moisture
amounts will be anywhere from 2-4 sigma above normal, with PWATs
above 1.5 inches in southern Arizona, and above 1 inch across much
of the rest of the Southwest. The upper level disturbance tracking
west out of New Mexico will force numerous thunderstorms to form
across Arizona. The storms will slowly track westward. Greater
concentrations of storms are expected along the Mogollon Rim where
topography will help allow the storms to congeal along the Rim. Due
to the above normal amounts of moisture, the storms will be capable
of heavy rainfall with the strongest cores possibly producing
rainfall rates to 2 inches per hour. Given the very favorable
hydrology of the Desert Southwest for flash flooding, given
generally very hydrophobic soils and bare rocks, the Slight Risk
remains in place across much of Arizona, with a higher-end Slight
stretching from the southeast corner of the state northwestward
along the Rim to the Grand Canyon. As usual, slot canyons, dry
washes, and other low-lying areas will be more susceptible to
impactful flash flooding downstream of the heaviest rains.

Further north across the Great Basin, the area will be on the
western periphery of the large ridge over Colorado and a nearly
stationary longwave trough off the coast of northern California. A
separate shortwave trough will track across Nevada and into Idaho
this afternoon. Given similarly anomalous amounts of atmospheric
moisture in place as well across this largely flash-flood prone
area from the Sierras east through Utah, clusters of storms will
form in this area associated with the upper level shortwave.

The inherited Slight was expanded west to include the Sierras,
where upslope will greatly contribute to afternoon and evening
thunderstorm activity there, while the steep slopes will support
fast-forming flash flooding downstream of any heavy rain producing thunderstorms. Elsewhere, few changes were needed, as many of the
areas in the Slight that will be impacted by storms again today
were impacted on previous days, worsening the flash flooding risk.

...Ohio and Tennessee Valleys into the Northeast...

Much of the flooding risk across the eastern half of the country
today will be in association with a strong cold front at the
leading edge of a strong longwave trough over the Great Lakes
pushing south and east across the Ohio and Tennessee Valleys as
well as into the Northeast. Anomalous moisture originating in part
from T.S. Bertha in the Gulf will ride northeastward ahead of the
front, providing plentiful moisture for numerous thunderstorms to
form, some of which will produce multiple-inch-per-hour rainfall
rates. A few areas within the broader Slight Risk are likely to
see more rainfall. In central Kentucky and central Tennessee, a southwest-to-northeast oriented band of storms is expected to form
on the leading edge of the cold front, with mesoscale "slow-downs"
in the front's progression allowing for a second round of activity
possibly forming over these same areas where FFGs are depressed
from heavy rainfall in recent days.

The greatest rainfall totals are expected to be across portions of
southeastern Virginia, generally from the Richmond metro east
across the Bay and impacting the lower Maryland and Virginia
sections of the Delmarva. Here, a plume of greater moisture will
interact with the front which will be slowed by its passage across
the mountains. An early to mid afternoon round of storms with the
initial approach of the upper level trough and associated shortwave
energy will move across southern Virginia first. Much more numerous
storms will impact the area in the evening hours as the main front
approaches the area. Despite the loss of daytime heating, the front
is expected to stall over southern Virginia, which could very well
allow for a prolonged period of training storms to set up in the
aforementioned area, which will persist through the overnight. A
short-fused Moderate Risk cannot be ruled out should this evolution
play out as expected by several of the CAMs.

Finally, across the area form northern New Jersey northeast into
the Hudson Valley, morning thunderstorms caught along the Catskills
and Poconos associated with a warm front may start out the day with
a period of training thunderstorms as moisture and instability
levels increase south of the front. This will likely be the feature
that causes the most rainfall in the area. Once the fast-moving
cold front sweeps eastward across the area, resulting in a much
shorter period of widespread thunderstorm activity, its passage
will end the threat for heavy rain in this area for the night.

...Gulf Coast/Tropical Storm Bertha...

As has been the case for several days, the convective pattern with
Bertha in the guidance is little changed. Northeasterly shear will
continue to keep any persistent heavy rainfall well south of the
Gulf Coast for the next several days. Only small and isolated bands
of rain trying to wrap around the center will impact the coast.
The inherited Marginal Risk remains little changed from Louisiana
through the Florida Panhandle.

Wegman


Day 2 Valid 12Z Wed Jul 22 2026 - 12Z Thu Jul 23 2026

...THERE ARE SLIGHT RISKS FOR EXCESSIVE RAINFALL OVER PORTIONS OF
THE INTERMOUNTAIN WEST AS WELL AS FROM NORTHERN GEORGIA THROUGH THE
TIDEWATER OF VIRGINIA AND NORTH CAROLINA...

...Intermountain West...

Highly anomalous amounts of atmospheric moisture associated with
the monsoon over the Intermountain West will be activated by rapid
height falls as an upper level and highly negatively tilted trough
pushes east from off the coast of Washington and Oregon. Meanwhile,
separate upper level energy undercutting the ridge will also
provide additional forcing further east across eastern Idaho and
Wyoming. Once again, numerous thunderstorms will form in the
anomalous moisture and for many areas, will be tied to the local
topography. Few changes were needed with this update. The greatest
amounts of rain look to concentrate in western Wyoming, where any
storms south of Yellowstone could necessitate a higher-end Slight
for some of those areas, as well as for the Uintas of northern
Utah. With nearly all of the forcing further north, the Marginal
Risk into southern Arizona and southern New Mexico was trimmed
significantly with this update, as ridging quickly overtakes this
area and limits convective potential south/west of the Mogollon Rim
as a result.

...Carolinas, Southern Virginia, and Northern Georgia...

A strong cold front running into highly anomalous moisture being
siphoned from the circulation of Tropical Storm Bertha will
exacerbate the gradient of moisture along the frontal interface
through the day across the Carolinas and into southeastern
Virginia. This will work to keep any forward progress of the front
minimal. Storms will train along the front, especially across
northeastern North Carolina and into southeastern Virginia. This
area remains in a higher-end Slight Risk and with the stalled out
front remaining to guide the frequent development of additional
storms, a Moderate Risk upgrade in areas where the storms focused
in the Day 1 period remains a distinct possibility. Guidance has
been laser focused in this area and so forecast changes have been
minimal. Further south and west, however, guidance has become
increasingly optimistic on storms developing further west into the
southern Appalachians. As such, the Slight Risk was expanded west
to include this region from north of Atlanta through the western Carolinas.

...Tropical Storm Bertha/Gulf Coast...

Strengthening shear across the circulation will continue to keep
any organized convection and meaningful rainfall out over the open
waters of the Gulf. The immediate coastline could still see amounts
greater than an inch, but the rainfall footprint continues to shift
off the coast. In coordination with LIX/Slidell, LA forecast
office, the inherited Slight Risk for this region was downgraded
with this update, with the overall area of the surrounding Marginal
remaining little changed. What little rainfall does impact land
areas remains with the potential to be locally heavy, so
unfortunately no changes to the Marginal Risks can be made so long
as Bertha remains a tropical entity.

Wegman
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 220826
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
426 AM EDT Wed Jul 22 2026

Day 1 Valid 12Z Wed Jul 22 2026 - 12Z Thu Jul 23 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR SOUTHEASTERN
VIRGINIA AND EXTREME NORTHEASTERN NORTH CAROLINA...

...Southeast...

A strong but painfully slow moving cold front draped across
Virginia today will continue to act as a train track along which
numerous showers and thunderstorms will move throughout the day and
into tonight. It's probable that many areas from western North
Carolina through Raleigh and into the Hampton Roads area of
southeast Virginia will see more time over the next 24 hours seeing
moderate to heavy rainfall than dry time. The heaviest and most
persistent rainfall will be into extreme northeastern North
Carolina and much of southeastern Virginia southeast of Richmond
today. The Hampton Roads metro appears to be the most at risk of
the metro areas expected to be impacted by heavy rains today. It's
likely areal averages in the Hampton Roads area will exceed 3
inches today through tonight. Given both the persistence of the
heavy rain and urban concerns, the inherited Moderate Risk area
will remain unchanged with this update, generally following the
state line east from I-95 to the mouth of the Chesapeake.

Elsewhere the Slight Risk area extending from northern Georgia to
the Delmarva was shrunk both on the north and south sides with this
update. The CAMs guidance are in good agreement on the corridor
where heavy rain and flash flooding will be, increasing the
confidence that a smaller latitudinal range will be covered by the
heavy rain. As such, the southeastern corner of NC and all but
northern SC were removed from the risk categories as the heaviest
rains will stay north of those areas for today. They'll get their
turn in the coming days. The length of the front will promote heavy
rain development towards the west, and as such the Slight was
expanded west into northeastern Alabama with this update, where the
combination of the front and topography will both support areas of
heavy rain and widely scattered instances of flash flooding.

...Intermountain West...

The Slight Risk area covering an expansive area of the
Intermountain West from southwestern Montana south through
northwestern New Mexico was largely unchanged with this update.
However, in coordination with ABQ/Albuquerque, NM forecast office,
the Slight Risk area was expanded south along the AZ/NM state line
with this update. Plentiful burn scars, relatively little amounts
of rain it's taken in some areas to cause flash flooding, and many
areas not seeing recent flooding at all are all contributing
factors to the Slight Risk upgrade. Meanwhile further north, the
heaviest rainfall totals will be tied to the topography in many
areas from the Bitterroots through Yellowstone, much of Utah and
western Colorado. With sufficient upper level forcing helping the
storms to form and cause flash flooding, it's probable in many
instances that any storms that start along the topography will move
off the mountains towards the northeast, so lower elevation valleys
in between also remain in the Slight Risk for flooding.

...Gulf Coast/Tropical Storm Bertha...

T.S. Bertha will continue to struggle from strong northeasterly
shear pulling nearly all of the significant associated rainfall
south over the open waters of the Gulf. With little rain expected
along the Gulf Coast, the inherited Marginal remains little
changed. The Marginal mostly covers the fact that any significant
tropical cyclone carries inordinate amounts of atmospheric
moisture, even when being sheared. That moisture can easily support
heavy rainfall, even if isolated, so the Marginal threat remains.

Wegman


Day 2 Valid 12Z Thu Jul 23 2026 - 12Z Fri Jul 24 2026

...THERE'S A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN NORTH CAROLINA...

...Southeast...

A strong and very slow moving cold front draped across portions of
the Mid-Atlantic on Wednesday makes only very slow progress through
the day Thursday across far southern Virginia and northwestern
North Carolina. A second day of intense rainfall in the form of
seemingly endless trains of storms will impact much of the
Carolinas on Thursday. The good news is the southward progress of
the front on the order of about 50 miles or so will spare most of
Virginia much heavy rainfall for yet another day. However, this
means the heavy rain simply impacts areas further south across much
of North Carolina and northern South Carolina. Unfortunately there
looks to be some overlap in the heavy rainfall footprints from
Wednesday into Thursday, particularly in northeastern North
Carolina, likely extending from Norfolk south and east. Once again
the heaviest rainfall amounts will likely concentrate along the
coast. As such the Moderate Risk for this period was also
unchanged, focused from I-95 east and from I-40 north and east.

Further west, a similar situation remains as on Wednesday.
Painfully slow southward movement means many of the same areas get
hit with heavy rains again on Thursday as on Wednesday. The Slight
Risk was expanded west along the front due to the large amounts of
atmospheric moisture in place immediately ahead of the front. Many
areas have PWATs above 2 inches. The Slight Risk area includes
metros Birmingham, AL, Atlanta, and into Charlotte, NC. All 3 of
these metros have some risk of training storms, with Charlotte the
highest of those 3.

...Central Plains...

A pair of nocturnal MCSs, one Wednesday night into Thursday
morning, and a second much stronger one Thursday night into Friday,
will impact portions of southeastern Nebraska, northeastern Kansas,
and into small portions of Iowa and Missouri through the period.
These back-to-back MCSs will sufficiently soak the soils such that
the heavy rain with Thursday Night's MCS will cause widely
scattered instances of flash flooding, especially where urban areas
such as Lincoln, Topeka, St. Joseph, and possibly Omaha and Kansas
City are impacted. The area of the Slight was adjusted, but remains
little changed with this update. The isolated flash flooding threat
represented by the Marginal extends well west of there through
nearly all of Wyoming and Colorado. While the flooding threat
diminishes considerably in these states compared with Wednesday,
the leftover saturated soils and still likely formation of showers
and storms will keep an isolated flash flooding threat going.

...Bertha/South Texas...

Latest CAMs guidance are starting to come into agreement on a
solution that keeps the circulation of Bertha intact over the
northwestern Gulf before the westward moving storm moves inland in
Texas near or south of Houston. As such, the persistent convection
that continues to focus south/southwest of the center eventually
impacts land areas, in this case in south Texas. A Marginal Risk
covering much of South Texas was introduced with this update. It's
likely that a Slight Risk upgrade will be needed with future
updates, short of a northward jog in the guidance that kills off
the rain much earlier, as the guidance had been showing in recent
days. The area most likely to see that upgrade is around Corpus
Christi through Victoria.

Wegman
$$
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* Origin: capitolcityonline.net * KY, USA (618:250/10)