FOUS11 KWBC 280725
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
225 AM EST Sat Feb 28 2026

Valid 12Z Sat Feb 28 2026 - 12Z Tue Mar 03 2026

...Northern High Plains, Great Lakes, & Northeast... Days 1-2...

A narrow but intense corridor of moderate to heavy snow will track
rapidly east-southeast from the Dakotas to the western Great Lakes
today. The heaviest snow late this morning will center from
southeastern North Dakota-northeastern South Dakota into southern
Minnesota, where strong low-mid-level frontogenesis and favorable
upper jet forcing will likely support a brief period of rates
exceeding 1"/hr. While this will be a fast-moving system, the
thermal profile remains cold throughout the column, supporting high snow-to-liquid ratios and a fluffy snow that will accumulate
quickly. WPC probabilities indicate that additional accumulations
(after 12Z) of 2-4" are likely from southeastern North Dakota-
northeastern South Dakota through southern Minnesota into southern
Wisconsin today. Embedded within this axis is an area of 30 percent probabilities for amounts over 4" centered over southern Minnesota.

As the system moves across the Great Lakes on Sunday, forcing is
expected to weaken and the band is forecast to become disorganized,
with a diminishing threat for heavy accumulations downstream.

...Central Plains into the Mid-Atlantic... Days 2-3...

The synoptic setup will be driven by a southern stream shortwave
trough ejecting from the Pacific, suppressing a downstream ridge
centered over the Southwest on Saturday before tracking into the
Central Plains on Sunday. This upper-feature will be guided by
northern stream jet streak, steering the energy toward the Mid-
Atlantic while simultaneously pushing a surface cold front south
into the Southern Plains and the Southeast. Amplifying low level
winds will tap Gulf moisture, supporting deepening moisture and a
broadening precipitation shield developing well north of the
boundary. A northward-surging warm nose will favor a transition to
a wintry mix along the northern edge of the precipitation shield
from eastern Nebraska-Kansas through the mid Mississippi into the
Ohio valleys Sunday into early Monday, while a persistent surface
high-pressure wedge will support a similar mix of precipitation
types over the central Appalachians into the Mid-Atlantic Monday
into early Tuesday.

For most of these areas, WPC probabilities for measurable ice
(0.01") max out in the 30-50 percent range. A notable exception
are the central Appalachians, where probabilities reach 70 percent
along the West Virginia Allegheny Mountains by early Tuesday, with
some 30 percent probabilities for accumulations over 0.10" there
as well. Probabilities suggest that snow accumulations will remain
an inch or less for most impacted areas. The latest run only shows parts
of northern Missouri and isolated parts of the West Virginia
mountains with probabilities greater than 50 percent for amounts
over an inch.

Pereira

$$
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FOUS11 KWBC 010656
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
156 AM EST Sun Mar 1 2026

Valid 12Z Sun Mar 01 2026 - 12Z Wed Mar 04 2026

...Central Plains to the Tennessee Valley...
Days 1-2...

Migrating shortwave ejecting out of the Rockies through the Central
Plains to Ohio Valley will lead to a period of mixed precipitation
from KS/NE, east into the Ohio Valley. Initial wave of precip will
form across the Central Plains with a degradation of the lower
boundary layer over time as a marginal warm-nose protrudes the
layer between 925-700mb leading to a band of snow on the northern
periphery of the SLP center with more of a light sleet/freezing
rain signature along and north of I-70 from Northeast KS through
MO. Freezing rain accretion of 0.01-0.05" will be most common
across this area with WPC probs of >0.01" running between 30-60%
over the aforementioned corridor, but well below 10% for >0.1"
meaning limited chances for more considerable impacts.

Further east into the Ohio Valley, western edge of the strong
surface ridge pressing Arctic air into the region will lead to a
touch better isentropic ascent pattern as the slowly maturing SLP
migrating east will allow for a better 850mb jet nosing up into
the very cold boundary layer present across the OHV with the
southern fringes of freezing to sub-freezing air located along the
KY/TN border. Fairly high probs (40-70%) for at least 0.01" are
located across the northern half of KY with the best chance for
~0.05-0.1" located north of I-64. Snowfall of 1-2" are relatively
low across portions of OH/IN with probs for >1" only between 10-30%
over the central and southern portions of each state.

...Mid-Atlantic to Northeast...
Day 2-3...

There has been very little deviation in the forecasted pattern
expected with the next disturbance to impact the Mid-Atlantic and
Northeastern CONUS. An amplifying mid- level trough ejecting out
of the Great Basin will track steadily eastward Monday night
through Tuesday, leading to a surface low formation that will
track along a wavering warm front/stationary front draped eastward
through the Mid-Atlantic. As this low moves east in conjunction
with its parent trough, downstream height rises will occur through
intensifying WAA, with the resulting overrunning/upglide leading to
an expansion of precipitation from the Mid-Atlantic/Central
Appalachians into the Northeast/New England, especially as PWs
surge to above the 90th climatological percentile according to
NAEFS. With Canadian high pressure quickly retreating to the E/NE
ahead of this system, the warm nose accompanying the WAA will be
unobstructed, and this will likely result in a rapid transition
from snow at precip onset, to a mix of sleet/freezing rain, and
eventually rain, even as far north as southern New England. Before
that transition, some impactful winter weather is likely through
briefly heavy snow (although accumulations should be modest) and
the icy sleet/freezing rain combination which will lead to some
satisfactory ice accumulations in the higher elevations of the
Central Appalachians and neighboring valleys where CAD signatures
remain prevalent through Tuesday morning. WPC probabilities for
snow indicate a low-end risk (20-50%) of at least 2 inches of snow
across the higher elevations of the Adirondak's, Green and White
Mountains of VT/NH. For ice, there is a moderate risk (40-80%
chance) of at least 0.1" from the Central Appalachians into the
Laurel Highlands of PA, with locally as much as 0.25" possible.

...Central Rockies to Pacific Northwest...
Days 2-3...

A potent shortwave ejecting out of the Pacific will translate
eastward into the Great Basin and then Four Corners states by
Tuesday morning. This shortwave trough is forecast to close off
across the Inter-Mountain west between UT/CO, helping to initiate
cyclogenesis in the lee of the Rockies as ascent becomes maximized
in the LFQ of a subtropical jet streak arcing towards the Central
Plains. As this low strengthens, increased moisture funneling
northward from the Gulf will track NW into CO/WY/UT as the
accompanying theta-e ridge rotates cyclonically around the low.
This will create significant snowfall accumulations, generally
above 7000 ft, across the Uintas, Tetons, Wind Rivers, and CO
Rockies, including the Park Range and northern Front Range. In
these areas, WPC probabilities of more than 4 inches of snow reach
50-80%, with locally up to 10 inches possible in isolated locations.

By D3, a second potent trough will enter the Pacific coast with
a solid mid-level moisture advection pattern into the Pacific
Northwest. This will allow for snowfall to occur across the
Northern Cascades with snow levels generally primed between
4000-4500ft AGL leading to mainly heavier snowfall totals above the
passes with the maxima focused >6500ft elevation. This will lead to
WPC probs of more than 60% for >4" focused within the higher
elevations of the Northern Cascades and Olympics.

Weiss/Kleebauer

$$
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FOUS11 KWBC 020703
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
203 AM EST Mon Mar 2 2026

Valid 12Z Mon Mar 02 2026 - 12Z Thu Mar 05 2026

...Ohio and Tennessee Valley's... Day 1...

Weak shortwave traversing through generally zonal flow from the
Central Plains to the Southern Appalachians will create a period of
modest ascent across the region. Current WV satellite and radar
composite shows the disturbance situated over the mid-Mississippi
Valley this evening moving due east with sights generally along the
central Ohio River Valley. Low-level baroclinicity along a cold
front stalled across the Lower Tennessee Valley will allow for
maintenance of surface low pressure in conjunction with the mid-
level shortwave, tracking eastward along the front allowing for an
enhancement of precipitation in the confines of the Ohio and
Tennessee Valley's, respectively. Despite the weak nature of this
surface low, downstream warm and moist advection will intensify on
850mb winds surging out of the Gulf, transporting moisture and a
warm nose northward, with increasing isentropic upglide leading to
an expansion of precipitation from the Mississippi River to points
east with the northern periphery of the precip field delegated to
the expected winter p-types. The column will remain marginally
supportive of winter weather, however, thanks to the warm nose
protruding the lower confines of the boundary layer meaning the
swath of snow or freezing rain will be relatively narrow,
especially south-central IL through southern OH. Total snowfall is
expected to be minimal at less than 2". However, WPC probabilities
indicate a 50-90% chance of at least 0.01" of ice, with some
locally higher totals approaching 0.1" for southern Ohio around the
proximity of Cincinnati and points north away from the immediate
Ohio River basin as noted via lower probs (10-25%) for the 0.1" threshold.

...Mid-Atlantic to Northeast... Day 1-2...

Mid-level trough over the mid-Mississippi Valley will advance
downstream into the Ohio Valley with an attendant surface low
migrating east along a stalled frontal boundary located over the
Lower Tennessee Valley as of early this morning. As this low moves
east in conjunction with its parent trough, downstream height
rises will occur through intensifying WAA, with the resulting overrunning/upglide leading to an expansion of precipitation from
the Mid-Atlantic/Central Appalachians into the Northeast/New
England, especially as PWs surge to above the 90th climatological
percentile according to NAEFS. With Canadian high pressure quickly
retreating to the E/NE ahead of this system, the warm nose
accompanying the WAA will be able to surge quickly northeast, and
this will likely result in a rapid transition from snow at precip
onset, to a mix of sleet/freezing rain, and eventually rain, even
as far north as southern New England. Before that transition, some
impactful winter weather is likely through briefly heavy snow
(although accumulations should be modest) and the icy
sleet/freezing rain combination which will lead to some impactful
ice accumulations in the higher elevations of the Central
Appalachians and neighboring valleys where CAD signatures remain
prevalent through Tuesday morning.

WPC probabilities for snow exceeding 2" each day exceed 30% only in
a few isolated areas, the higher Central Appalachians D1, the
Greens and Berkshires on D2, and coastal/Downeast Maine on D2-2.5.
Total snowfall may reach 4" in a few of these areas, mainly in
elevations above 4000ft MSL.

The icing is expected to be more impactful, especially in the
Central Appalachians, where the probability for at least 0.1" of
ice exceeds 50-90% in the higher elevations of the Alleghenies,
the Blue Ridge of VA, and into the Laurel Highlands of PA. Latest
probs for >= 0.25" have come up towards 30-50% within a narrow
corridor along the spine of the Central Appalachians of east-
central WV, mainly as you move south of the Canaan Valley along the
eastern Continental Divide. More widespread icing exceeding 0.01"
is expected from far NW NC through southern New England, including
the I-95 corridor from Washington, D.C. through New York City where
the Tuesday commutes could be impacted by light icing and mixed
precipitation. Highest probabilities for >0.01" of ice accretion
will be found generally northwest of the fall line, especially as
you west of the Blue Ridge and Susquehanna Valley in PA.

...Central Rockies... Days 1-2...

A potent closed low emerging from the Pacific has begun to push
ashore this evening over Northern California with an expectation
of continuing eastward across the Great Basin today, eventually
ejecting into the Central Rockies by Tuesday morning. Although
this feature is now progged to weaken as it translates eastward, it
will still maintain sufficient amplitude to drive robust height
falls/PVA into the Central Rockies, which when combined with a
modest (90-100kt) jet streak placed favorably into the Central
Plains, will result in lee cyclogenesis Monday evening. This low
will deepen at least marginally as it advects E/SE into Tuesday,
while downstream moisture from the Gulf gets wrapped cyclonically
into the system to create anomalous PWs as high as the 97th
climatological percentile. The combination of synoptic ascent with
upslope enhancement north/northwest of the surface low will create
areas of heavy snow, especially above 7000 ft in the Uintas,
Tetons, Wind Rivers, Laramie Range, and across much of the CO
Rockies including the Park and Front Ranges. In these areas, WPC
probabilities are high (50-80%) for at least 4" D1 in NW WY,
expanding to include the terrain of UT and CO on D2. Locally as
much as 10" of snow is possible in the higher terrain.

...Pacific Northwest... Day 2-3...

An amplifying shortwave trough currently positioned over the Gulf
of Alaska will gradually advect southeastward, coming onshore
Wednesday morning. As this shortwave moves onshore, it will produce
impressive height falls which will overlap with the RRQ of a
meridionally strengthening jet streak (downstream of the primary
trough axis) to drive pronounced deep layer lift into the
Northwestern CONUS. At the same time, confluent flow immediately
ahead of the mid-level trough will gradually back to be more SW,
pumping elevated IVT onshore to provide the moisture needed for
heavy precipitation. Global deterministic and their ensembles are
starting to converge on a relatively modest IVt advection regime
~250 kg/ms, aligning with the ECENS outputs that have been
consistent within this range for the past few days. This scenario
should result in periods of heavy snow, especially in the
Olympics, Cascades, and Northern Rockies, with snow levels falling
steadily from around 5000 ft to 4000 ft beneath the upper trough
and a corresponding cold front. WPC probabilities D3 are high

70%) for at least 4" of snow along the spine of the Cascades of

OR and WA, the highest terrain of the Olympics, and parts of
OR/ID/MT from the Blue Mountains through the Sawtooth Region and
into the far Northern Rockies near Glacier NP.

Weiss/Kleebauer
$$
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FOUS11 KWBC 030719
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
219 AM EST Tue Mar 3 2026

Valid 12Z Tue Mar 03 2026 - 12Z Fri Mar 06 2026

...Mid-Atlantic to the Northeast... Days 1 & 3...

The general synoptic pattern is unchanged from the previous
forecast. Weak shortwave trajectory from the Mid Atlantic will
motion northeastward off the the coast of Southern New England
with moisture carried poleward in the process. 1041mb surface
ridge positioned off Cape Cod will lead to a shift in the low-level
flow by morning to a more easterly orientation with a nosing low-
level jet around 850mb allowing a warm air protrusion into the
boundary layer as we push through D1. Cold air will slowly retreat
northward with snow/ice across the Northeast changing to rain, even
as far north as Southern New England. Areas north of I-90 will hold
on to cold air the longest with snow/ice the primary p-types
through the event. Best ascent will be fixed to the southeast,
however, so totals for freezing rain and snow will be relatively
modest, at best leading to some minor to bordering moderate impacts
where ice accretion approaches 0.1" or greater. Low pressure will
eventually carry the system off the coast by early Wednesday
leading to an end of the impact from this disturbance.

Snow amounts will generally be light, especially in the Northern Mid-
Atlantic. From around I-90 northward, WPC probabilities for at
least 4 inches of snow are low (10-40%) as most amounts should be
in the 1-3" range. Higher elevations of the Green and White
mountains show the highest chance for at least 4 inches of snow.
The freezing rain footprint will extend from the WV Panhandle into
the Allegheny front, northward along the I-81 corridor and as far
west as the I-79 corridor northward to about I-90 and eastward to
about I-95. Freezing rain accumulations will be highest where the
cold air holds on longest near the highest QPF, which is forecast
to be over the central Appalachians and highlands of west-central
PA. WPC probabilities for at least 0.10" icing are between 30-60% over west-central PA up towards the NY state line with lower probs <20%
for parts of the Catskills and Berkshires.

By D3, a potent mid-level shortwave will eject east-northeast out
of the Midwest, aiming sights at Upstate NY through New England by
the end of the period. A trailing axis of confluence over Atlantic
Canada with a strong 1038+ mb surface ridge migrating east out of
Central Canada will set the stage for a stout low-level CAD
signature within the valley's of New England leading to a
heightened threat for freezing rain as the boundary layer between
925-700mb will be too warm, promoting liquid hydrometeors. Shallow
but impressive CAD will lead to a transient light to moderate
freezing rain between 00-12z Friday with WPC probabilities for

0.1" already signaling 10-40% potential across the

Hudson/Champlain Valley's along the NY/VT border, as well as
through the southern Green mountains and neighboring Berkshires.

...Central Rockies... Day 1...

Current WV satellite and UA analysis shows a very distinct closed
upper reflection located over the southern reaches of the Tetons
with snowfall occurring over the Wasatch over into the WY ranges
and the northwestern portion of CO. This threat will carry through
the morning with snowfall likely to breach 4" across portions of
the Central Rockies including the Medicine Bow range located over
northern CO and southern WY. Probs continue to come in between
40-70% for those areas of additional snowfall >4" leading to totals
likely to push 10+" through the storms life cycle. System will
exit the second half of the forecast leading to an end to the
threat as we move into the evening hours.

...Pacific Northwest, Great Basin, and Northern Rockies... Days 2-3...

A deepening system in the Gulf of Alaska will move southeastward
through today, bringing a surge of moisture into the Pacific
Northwest ahead of a cold front. Moisture levels and IVT anomalies
will be modest, and snow levels will start around 5000-6000ft
before falling post- FROPA to around 4000ft Wednesday then to near
3000ft Thursday as precipitation becomes much lighter. Snow will
spread eastward to the Northern Rockies (northern ID to
northwestern MT) early Wednesday then to the Great Basin late
Wednesday into Thursday as the upper trough moves into southwestern
OR. Snow could be heavy at times near/above pass level as snow
levels fall across the Cascades tomorrow night. By the end of the
forecast period, the upper trough may deepen into a closed low over southwestern UT with snow spreading into the Uintas and Wasatch as
well as western WY ranges, continuing into the medium range.

WPC probabilities for at least 8 inches of snow are highest over
the WA/OR Cascades for D2, generally above 4000-5000ft. Plowable
snow (at least a couple inches) is likely (>80% chance) around
Snoqualmie Pass. To the east, WPC probabilities for at least 8
inches of snow are >50% above 5000-6000ft or so over the Blue
Mountains, central ID ranges, western MT, UT mountains, and
northern NV.

Fracasso/Kleebauer

$$
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FOUS11 KWBC 040749
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
249 AM EST Wed Mar 4 2026

Valid 12Z Wed Mar 04 2026 - 12Z Sat Mar 07 2026

...Northeast... Day 2...

A potent mid-level shortwave (currently over the Rockies) will
eject east-northeast out of the Midwest and weaken as it rides the
quasi-zonal flow into the Northeast. A trailing axis of confluence
over Atlantic Canada with a strong 1038+ mb surface ridge migrating
east out of Central Canada will set the stage for a mixed ptype
event as cold air remains entrenched over areas along and north of
I-90. Cold air damming, aided by a cold front from the Great Lakes
to Nova Scotia, will favor freezing rain as the precipitation mode
though some light snow is possible over New Hampshire into
southwestern Maine, which will be fully into the colder airmass.
Precipitation starting Thursday evening will continue through
Friday as the shortwave and associated weak area of surface low
pressure races eastward into the Atlantic. WPC probabilities for
at least 0.10 inch icing are moderate (40-70%) over the southern
Green Mountains and Berkshires as well as across southern New
Hampshire (Monadnocks) into the Worcester Hills. Probabilities for
at least 0.25 inch icing is highest (20-40%) over the southern
Greens and Berkshires. Lighter icing (>0.01") is probable for much
of the Adirondacks and Catskills across Vermont and New Hampshire
into northern CT/RI.

...Pacific Northwest, Great Basin, and Rockies... Days 1-3...

A mature system in the Gulf of Alaska weakening early this morning
will shunt a southern mid- level trough into the Pac NW today,
carrying a potent cold front ashore. A surge of modest moisture
and IVT, coupled with snow levels initially around 5000-6000ft,
will limit impacts. However, post- FROPA, snow levels will fall to
around 4000ft today then to near 3000ft Thursday as precipitation
becomes much lighter. Snow will spread eastward to the Northern
Rockies (northern ID to northwestern MT) early this morning then
to the Great Basin late this afternoon into Thursday as the upper
trough moves into southwestern OR. Snow could be heavy at times
near/above pass level as snow levels fall across the Cascades
today and then again tomorrow evening as the upper trough moves
through WA/OR. On Thursday, the trough will dig into Utah which
will enhance snowfall into the Uintas, WY ranges, and into the CO
Rockies, favoring upslope regions with ranges oriented
perpendicular to the northwesterly flow. Snow levels will continue
to fall across the region, initially around 7000ft in WY/CO late
Thursday but dropping to below 5000ft early Friday. This may
bring some lighter snow to areas east of the Front Range and High
Plains, including from eastern CO and southeast WY to western NE
and central SD.

WPC days 1-2 probabilities for at least 8 inches of snow are >50%
over the WA/OR Cascades, generally above 4000-5000ft. Plowable snow
(at least a few inches) is likely (>95% chance) around Snoqualmie
Pass. To the east, WPC probabilities through day 3 for at least 8
inches of snow are >50% above 5000-6000ft or so over the Blue
Mountains, central ID ranges, western/southwestern MT, northern NV
ranges, Uintas/Wasatch, and into the Wind River, Laramie, Park
Range, and Medicine Bow ranges. Maximum snowfall amounts of 1 to 2
feet can be expected in the highest peaks of these mountain ranges.

...Central/Northern Plains and Upper Midwest... Day 3...

More uncertainty regarding QPF and ptype exists throughout
the central/northern Plains and Upper Midwest on day 3 (12z Fri.
to 12z Sat.) as this system ejects eastward. Although less likely
at the moment, should a stronger shortwave eject northeastward
across the Plains on Friday and spawn a deeper surface low along
the advancing cold front, a band of heavy snow is possible.
However, the GFS remains alone in this higher end scenario.
Current WPC probabilities for at least 2 inches of snow are low
(20-40%) from western NE to northern MN.

Snell/Fracasso

$$
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FOUS11 KWBC 050857
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
357 AM EST Thu Mar 5 2026

Valid 12Z Thu Mar 05 2026 - 12Z Sun Mar 08 2026

...Northeast... Days 1/2...

Shortwave low over IA early this morning will further weaken into a
trough as it shifts to the eastern Great Lakes today and over
central New England tonight. A 1040mb high over Quebec retains a
wedge of cold air over New England through the Hudson Valley. Warm
air advection ahead of the low overruns the cold setting up mixed
precip and some all snow well into the cold sector. Snow probs are
quite limited, generally around 20% for >2" over southern NH and
far southern Maine which depends on how far precip can shift into
the dry high. Otherwise, it's ice glaze potential from the
Catskills, Berkshires into the Litchfield Hills and over the
Worcester Hills where Day 1 probs for >0.25" are 20-60%. Plenty of
precip occurs with this system, so it will come down to surface
temperatures and efficiency of freezing rain with rate and wind
factoring in. As of now the potential for 0.5" ice is limited to
the Berkshires where the PWPF is around 10%.

...Cascades through the Rockies... Days 1-2...

A trough over Nevada this morning will dig down to AZ today and
promote lee-side sfc cyclogenesis over eastern CO tonight. In the
meantime, broad upper troughing over the northeast Pacific with low
pressure over central AK will direct a plume of Pacific moisture
across the NW on northwesterly flow.

Areas east of the trough axis will see moderate precip rates today with
lower snow levels around 4000ft over the UT/eastern ID ranges up
through western MT and western WY ranges. Onshore flow and snow
levels around 3500ft brings snow to the WA Cascades today. Day 1
PWPF >6" are 50-90% in southwest MT ranges and 40-80% from
northwest MT through the UT Ranges and up through the Bighorns in WY.

The central Rockies get the focus late tonight through Friday with
the lee-side low bringing some Pacific and west Gulf moisture back
over the CO Rockies. Day 2 PWPF for >6" are 40-80% over most of the
CO and southern WY Rockies which will be quite welcome. The snow
focus shifts to the Plains by late Friday night.

...Central/Northern Plains and Upper Midwest... Days 2/3...

A trough over Nevada this morning will dig down to AZ today,
promote lee-side sfc cyclogenesis over eastern CO tonight that
tracks over Iowa and Wisconsin Friday and northern Michigan early
Saturday. The strength of this low is the main point of uncertainty
with deeper solutions from the GFS and AiGFS (and now somewhat the
00Z CMC) develop a TROWAL band from western Nebraska through MN
while weaker solutions like the EC have only minor fgen banding on
the back side. WPC QPF favors decent fgen banding which would set
up some overrunning and a swath of wintry mix along with snow
banding. Day 2 PWPF for >4" are limited by the model variance with 20%
in western Neb and 5% in central SD. However, probs for >2" are 10%
or higher from western Neb through northern MN. Given the banding
potential and motion along banding orientation, some heavy snow is
possible in narrow swaths west of the low track.


Jackson


$$
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FOUS11 KWBC 060905
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
405 AM EST Fri Mar 6 2026

Valid 12Z Fri Mar 06 2026 - 12Z Mon Mar 09 2026


...Rockies, Central/Northern Plains and Upper Midwest...
Days 1-2...

Full-latitude trough with the axis approaching the Four Corners
early this morning will continue to promote lee-side cyclogenesis
from the southern High Plains up through western/central KS and
eastern Neb/western Iowa today. Pacific and western Gulf moisture
wrapping around the lee-side low will continue across the CO
Rockies which are under the trough today with snow levels dropping
to around 5000ft. Day 1 snow probs for >6" additional snow after
12Z are 40-90% across the CO Rockies and the higher ranges through
central WY.

Those low snow levels will allow snow accumulation on the central
High Plains this afternoon west of the low track. Decent TROWAL
development from the strengthening low will allow fgen bands of
snow to form, first over the Denver metro, then extending northeast
from there across western Neb up into SD today. 00Z HREF mean snow
rate reaches 1"/hr over the Palmer Divide this afternoon and over
the eastern edge of the Neb Panhandle this evening.
Filling/weakening of the low then brings down the banded snow
threat for eastern SD and southern MN overnight. However,
redevelopment as the low approaches Lake Superior brings about
renewed banded snow threats to the northern WI/MN border, far
northern WI, and the western U.P. late tonight into Saturday. Day 2
snow probs for >2" are limited to around the Porcupine Mtns into
the Keweenaw Peninsula.

Mixed precip is expected near the low track today with Day 1 PWPF
for >0.1" ice 20-40% over southwestern to central MN.


...Northeast...
Days 1/2...

Shortwave trough over lower Upstate NY early this morning shifts
off Cape Cod by midday with ongoing freezing rain NW of Boston
lingering this morning. WAA ahead of the low crossing northern MI
tonight brings light precip to northern New England late tonight
into Saturday. Residual cold surface air brings a freezing rain
threat to the White Mtns of NH through western/northern Maine. Day
1.5 PWPF for >0.1" is 40-70% through this region.


...WA Cascades...
Day 3...

Powerful shortwave trough rounding a southern AK low directs
elevated Pacific moisture through WA on Sunday. Snow levels rise on
the WA Cascades to around 5000ft Saturday night before dropping to
around 4000ft Sunday under height falls. Day 3 PWPF for >6" snow is
40-80% above Snoqualmie Pass level on the northern WA Cascades.


Jackson



$$
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FOUS11 KWBC 070853
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
353 AM EST Sat Mar 7 2026

Valid 12Z Sat Mar 07 2026 - 12Z Tue Mar 10 2026

...Upper Midwest... Day 1...

Surface low center tracks northeast from WI early this morning
across northern MI through midday. Strung out comma head fgen
banding over southern MN lifts northeast across northern WI and the
western U.P. this morning. Right entrance jet dynamics aid lift and
allow snow rates around 0.5"/hr per 00Z HREF around 12Z in the
Bayfield area of WI and along the western U.P. shore/Porcupine
Mtns. Snow lifts northeast of the Keweenaw Peninsula by noon.

...New Hampshire and Maine... Day 1...

Warm air advection rain ahead of a trough is currently entering
western NY. This shifts to the White Mtns of NH and Maine later
this morning where subfreezing temps persist inland from the coast
as high pressure continues to retreat over Atlantic Canada. Day 1
PWPF for >0.1" are 20-30% in the interior terrain of Maine and the
White Mtns of NH.

...Washington to Northern Rockies... Days 2-3...

A trough shifts over the Gulf of Alaska today before digging south
down the BC coast through Monday. A tight baroclinic zone
accompanies this trough with a powerful onshore jet and enhanced
moisture that pushes into Washington early Sunday. Snow levels
around 6000ft in the moisture surge Sunday morning steadily
decrease through Sunday night, reaching around 500ft by 12Z
Monday. Will need to monitor precip likelihood for the Seattle
metro given Olympic shadowing in the westerly flow, but there is a
chance for snow down near sea level particularly (from a thermal
perspective) Monday night.

Otherwise it's terrain based snowfall late Sunday night through
most if not all of next week. This streams east across NW MT where
snow levels will be 1000ft or less starting Monday. Day 2 snow
probs for >6" are 50-90% for the WA Cascades and the Lewis Range in
Glacier NP. These probs expand down to Mt Hood for Day 3 and well
below pass level on the WA Cascades. The axis shifts south a bit
inland with Day 3 snow probs for >6" over the Bitterroots and
northern Absarokas in the 30-60% range.

Jackson

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

FOUS11 KWBC 080849
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
449 AM EDT Sun Mar 8 2026

Valid 12Z Sun Mar 08 2026 - 12Z Wed Mar 11 2026

...Pacific Northwest Through The Northern Rockies...

Days 1-3...

Deep mid-level low drifts southeast over the Gulf of Alaska today
through Monday with the trough south of it digging across
Washington with a strengthening zonal jet before stalling/lifting
north through midweek. Snow levels over the WA Cascades drop
through Monday morning from the current 6000ft to near sea level
Monday/Monday night. The first slug of moisture from this system is
currently pushing down the south end of Vancouver Island with
higher elevation 1"/hr snow rates over the north WA Cascades per
the 00Z HREF. Then renewed precip arrives this evening when snow
levels dip below 3000ft/Snoqualmie Pass level and reach 1000ft or
less by 12Z Mon. Onshore flow and precip persist pretty much
through the rest of this week in western WA. Will need to continue
to monitor Puget Sound convergence banding Monday night when snow
levels approach sea level for accumulating snow potential in the
greater Seattle metro. Otherwise, it's upslope based snow for the
WA Cascades with and inland axis shifting south down the MT Rockies
this afternoon through Monday with snow levels in the moderate
precip rates generally 4000-6000ft. Day 1 snow probs for >6" are
around 50% near Snoqualmie Pass and 50-80% in the higher NW MT
Ranges including the Lewis and Bitterroots. Day 2 snow probs for

8" are 60% near Snoqualmie Pass and 30-50% in the northern/Red

Lodge Absarokas. Day 3 snow probs for >8" are 85% near Snoqualmie
Pass and 30-60% in the Bighorns of northern WY.

The prolonged duration of moderate to heavy snow for the WA
Cascades at low snow levels through midweek will be quite remarkable.


...Northern Great Lakes...

Day 3...

A reinforcing trough rounding the Gulf of Alaska low today digs
across WA late Monday where it begins to draw the cutoff low
currently off the northern Baja Peninsula toward Texas. The sheared
southern stream remnant trough and the northern stream trough from
WA approach each other Tuesday night over the south-central Plains,
promoting strong inverted troughing downstream across the Midwest.
North of this trough axis will be overrunning precip with a
transition from a wintry mix to snow. These defined ptype changes
will need to be closely monitored as accumulating ice and snow are
likely. Day 3 snow probs for >4" are 40% in the MN Arrowhead and
30% in the western coastal U.P. South of this swath is the risk for
freezing rain with probs for >0.1" currently 10-30% over the
eastern U.P. and northern L.P. Since the low will track along/near
the axis of the inverted trough, duration of wintry precip over the
northern Great Lakes will persist into/through Wednesday, so stay
tuned for updated location and magnitude forecasts for snow and ice.


Jackson


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

FOUS11 KWBC 090910
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
510 AM EDT Mon Mar 9 2026

Valid 12Z Mon Mar 09 2026 - 12Z Thu Mar 12 2026

...Pacific Northwest Through The Northern Rockies...

Days 1-3...

Active winter weather continues across the WA Cascades and northern
Rockies through this weekend with particularly low snow levels
(especially for March) persisting into Wednesday.

A powerful zonal jet south of a Gulf of Alaska low will continue to
push across the WA/OR border as it continues to intensify to
150kt+ through tonight. A tight baroclinic zone has established
over central OR to southern MT with a moisture axis pushing across
western WA with showery activity through this evening under a
passing trough axis before tapering off under brief ridging
overnight. This is the coldest portion of this storm, but precip
should be pretty localized which may limit the snow coverage around
the greater Seattle metro tonight as snow levels dip below 500ft
MSL. Day 1 snow probs for >8" are over 50% above about 2000ft on
the WA Cascades and around 30% in the Bitterroots and just south
of Glacier NP.

Snow levels then rise to 1500ft on the Cascades Tuesday as
moisture content in the onshore flow increases along with snow
rates. Day 2 snow probs for >8" are over 50% above about 2500ft on
the WA Cascades and 40% for the Red Lodge/northern Absarokas and
higher Bighorns.

The next jet streak and onshore moisture surge increase is
Wednesday, again right into western WA. Snow levels quickly rise
above 3000ft Wednesday afternoon with high precip rates. Day 3 snow
probs for >12" are over 50% above 3500ft and around 60% in the
Bitterroots and Lewis Range. At least two more days of heavy
mountain snow, so stay tuned for further details on that forecast.

...Northern Plains through the Northern Great Lakes...

Days 2-3...

A southern stream cutoff low off Baja will eject east and open into
a trough before reaching TX Tuesday night. Considerable
sub-tropical Pacific moisture will stream across Mexico and be
joined by west Gulf moisture that surges up the Plains. Meanwhile a
northern stream trough crosses the northern Rockies Tuesday with
an inverted trough developing from the southern Plains to Chicago
Tuesday night with surface low development over southeast MI early
Wednesday. The surging moisture will wrap around the surface
trough/developing low, forming a comma head and connecting fgen
band over SD to southern MN Tuesday night. North of the low track
expect swaths of wintry mix before being all snow over far northern
WI and the U.P. Confidence is rising on a dry slot extending
through this wintry mix zone which complicates the QPF in this
case. There is decent storm track and QPF coverage from the 00Z
AIGFS/EC-AIFS and GFS on heavy banded snow over the U.P. and
sufficient QPF over the wintry mix zone for concerning freezing
rain accumulations. Day 2.5 snow probs for >6" are 40% in the Huron
Mtns and 30% along the central U.P. northern shore though these do
seem a bit suppressed. Ice probs have risen despite the risk for
dry slotting with the northeast L.P. having Day 2.5 probs for

0.25" peak around 40%. Interestingly the WSSI-P moderate impact

ice has a peak around 50% in a similar area. Overall this is a
fairly progressive storm, much more so than the prolonged ice storm
last March in this area.

...Northern New England...
Days 2/3...

Surface low pressure downstream of a northern stream trough
over the Upper Midwest tracks across New York on Wednesday before
crossing northern New England Wednesday night. A warm front
downstream of the low will extend ENE into New England, and then
lift through northern Maine with strong moisture advection driving
a warm nose over residual cold air from high pressure tracking
north of Maine Tuesday night. A wintry mix of sleet and freezing
rain spreads generally north of NY/VT and across north-central
Maine where Day 3 ice probs for >0.1" are 40-60%. Thermals likely
remain cold enough for the northern tip of Maine where Day 3 snow
probs for >6" are 40-60% in northern Aroostook Co.

Jackson

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

FOUS11 KWBC 100908
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
508 AM EDT Tue Mar 10 2026

Valid 12Z Tue Mar 10 2026 - 12Z Fri Mar 13 2026

...Cascades Through The Northern Rockies... Days 1-3...

...Washington Cascades Blizzard into Thursday...

Active winter weather continues across the WA Cascades and northern
Rockies through Friday night with particularly low snow levels
(especially for March) persisting through tonight.

A reinforcing shortwave trough rides a 150kt zonal jet positioned
south of a Gulf of Alaska low across the WA/OR border today. Low
snow levels (500ft or below) persist this morning over western WA
under the trough with snow levels rising to 1500ft this afternoon
as heights rise after the trough axis passage. Onshore flow
persists today with the next atmospheric river approaching tonight
with rates becoming moderate overnight with increasing winds. Day
1 PWPF for >8" is around 60% at Snoqualmie Pass and over 40% above
about 2000ft on the WA and northern OR Cascades as well as the Olympics.

A focused axis of 0.75 to 1" PW shifts across the western WA/OR
border Wednesday through Friday with a trough axis crossing early
Thursday. Powerful winds accompany the leadup to the trough axis
with 850mb winds of 40-60kt expected across the WA and northern OR
Cascades Wednesday night before easing into the 25kt range on
Thursday. Snow levels rise to 4000ft through Wednesday in the WAA
of the AR axis before dropping over WA into the 2000-3000ft range
late Wednesday night. Days 2/3 snow probs for >12" are quite
impressive, generally 50-80% above about 2500ft on Day 2 and 2000ft
on Day 3. Blizzard warnings are up for the WA Cascades through
Wednesday with the watch extending into Friday for this prolonged event.

This moisture axis extends inland over the northern Rockies through
this event. Snow levels rise there into the 4000-5000ft range
through Wednesday night before the moisture axis shifts south a bit
Thursday. Day 2 snow probs for >8" are 50-80% for the Bitterroots
through the Lewis Range before focusing on the Bitterroots,
Anaconda Range and southern Lewis Range on Day 3.

...Northern Plains through the Northern Great Lakes... Days 1-2..

Broad troughing over the northern tier of the CONUS focuses onto a
more defined northern stream trough over the northern Rockies today
which sweeps across the northern Plains tonight, the Upper Midwest
Wednesday, and the Great Lakes Wednesday night. A sinewy band of
moderate snow over north-central MN, northern WI, and the western
U.P. is from fgen on the leading edge of a developing inverted
trough developing downstream of the forming trough axis. An
additional factor in the developing storm is a cutoff low currently
over the Sea of Cortez that ejects to TX through tonight. This
reinforces the downstream inverted trough and promotes surface low
pressure development over IL tonight. Broad cyclonic flow develops
tonight with fgen snow banding over the north-central Plains
through central MN up through northern WI and the western U.P.
pivoting down to eastern Neb. Dry slotting is well defined now in
guidance south of the snow and north of the surface low. Mixed
precip will develop through this zone over central WI and
especially northern L.P. of MI. Day 1.5 snow probs for >4" are over
40% from northern WI through the north shore of the eastern U.P.
with embedded 60% probs for >8" in the Huron Mtns. Day 1.5 probs
for >0.25" are 40-60% in the northern U.P. east of I-75.

...Far Northeast... Days 2-3...

Potent northern stream shortwave lifting steadily eastward from the
Central Plains will cross into the Great Lakes/Ohio Valley Thursday
while amplifying. Downstream of this trough amplification, a
meridionally arcing jet streak will favorably influence ascent
through the right entrance region to help strengthen a surface low
tracking from lower Michigan through Ontario, before tracking north
of Maine late Wednesday night. Downstream of this system, moisture
advection will intensify from the Gulf, driven by potent 850mb
WAA, which will additionally surge the surface warm front
northward. The combination of the deep layer ascent with the
resulting fgen (as a result of the WAA) will create heavy
precipitation along the international border with Canada and then
into northern Maine. Precipitation will likely start as snow across
northern Maine, but everywhere else, and then later in the period
across northern Maine, a mix of sleet and freezing rain, eventually
becoming rain, is expected, as the warm nose surges northward. Day
2 ice probs for >0.25" are 30-50% in interior north-central Maine
with Day 2 snow probs for >6" limited to northern Aroostook Co.

Some LES can be expected in the wake of this low off Lake Ontario
late Thursday.

...Northern Plains to Northern Great Lakes... Day 3...

The potent shortwave trough axis crossing northern WA early
Thursday really amplifies over the northern Plains Thursday before
rapidly developing into a major low pressure system over the Upper
Midwest Thursday night. This progressive system will be on the
leading edge of a 150kt WNWly jet. A strong wind field and heavy
snow bands will develop with this low. Day 3 snow probs for >6" are
30-60% over northeast ND and across northern WI, much of the U.P.,
and the North Shore of MN. This coming on the heels of the
low tonight into Wednesday will make for a notable late-season
impact to the Upper Midwest/northern Great Lakes.

Jackson

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

FOUS11 KWBC 110909
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
509 AM EDT Wed Mar 11 2026

Valid 12Z Wed Mar 11 2026 - 12Z Sat Mar 14 2026

...Cascades Through The Northern Rockies... Days 1-3...

...Washington Cascades Blizzard into Thursday...

Active winter weather continues across the WA Cascades and northern
Rockies through Friday night with heavy precip and high winds
especially tonight.

A focused axis of 0.75 to 1" PW shifts across the western WA/OR
border through Friday night with a trough axis crossing tonight.
Powerful winds accompany the leadup to the trough axis with 850mb
winds of 40-60kt expected across the WA and northern OR Cascades
tonight before easing into the 25kt range on Thursday. Snow levels
currently in the 2000-3000ft range rise to around 5000ft this
afternoon in the WAA of the AR axis before dropping over WA into
the 2000-3000ft range late tonight as noted within the negative
temperature advection regime focused between 850-700mb. This will
be quite the snow event for the higher elevations of the WA
Cascades and the higher northern ID/northwestern MT ranges. Days
1-3 each have snow probs for >24" above 40% in the Cascades and 30%
in those ID/MT ranges (with only a little wobble in the axis south
on Day 2 before returning north for Day 3). Snow probs for >12" at
Snoqualmie Pass are 70% on Day 1, 95% on Day 2, and 70% again for
Day 3. Major impacts are expected across the WA Cascades, the
Bitterroots, western MT ranges and on Day 2 for northwestern WY ranges.

...Northern Great Lakes and Far Northeast... Day 1..

Northern stream trough over the Upper Midwest with southern stream
low over west Texas shift east to the Great Lakes/Southeast through
tonight. The surface low over northern IL rapidly develops as it
shifts across southern MI this morning and Quebec tonight. Banding
around the elongated 850mb low over WI/MI is continuing over the
U.P. with a separate area of light to moderate snow in central Neb.
This axis pivots more N-S through this morning before lifting into
Canada. Day 1 snow probs for >6" additional after 12Z are 50% in
the Huron Mtns and 20-40% in the eastern U.P. and far northern
Aroostook Co Maine.

Meanwhile WAA ahead of the low shifts across the eastern U.S. with
sufficient lingering cold over interior north- central Maine into
Coos Co NH where Day 1 ice probs for >0.1" are 40-80%. Ongoing ice
over the northern L.P. lingers this morning with 20% probs for an
additional 0.1" after 12Z in a swath of the northeastern part of the state.

...Northern Plains through Northern Great Lakes into Northeast... Days 2/3...

The potent shortwave trough axis crossing northern WA Wednesday
night on a 150kt potent WNWly jet really amplifies over the
northern Plains Thursday afternoon, producing a mature surface low
that crosses the northern Great Lakes Thursday night and pushes up
the St. Lawrence on Friday before reaching northern Maine Friday
night. A strong wind field and heavy snow bands will develop with
this low, though there remains some uncertainty with the track. The
EC-AIFS and CMC are farther south with a Day 2 QPF axis focused
just south of Duluth, while the GFS and NAM have the axis north
from Duluth. A compromised solution in between (WPC QPF actually
favors the south solution) is pretty close to the AIGEFS axis with
more magnitude. Day 2 snow probs for >6" are 40% over northern MN
with Day 2.5 probs 40-80% from the North Shore of MN, far northern
WI, and all of the U.P. and the northern L.P. This track then
continues east with Day 3 probs for >6" 40-60% over the Tug Hill
and southern Adirondacks. Unlike the previous system, this one is
much more simple with rain/snow and not a wintry mix. However, the
deep low will create quite a wind field with localized blizzard
conditions possible in spite of the North Woods' friction.


Jackson


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

FOUS11 KWBC 170624
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
224 AM EDT Tue Mar 17 2026

Valid 12Z Tue Mar 17 2026 - 12Z Fri Mar 20 2026

...Great Lakes southeast through the Mid-Atlantic... Day 1...

Strong low pressure which produced the blizzard over the Upper
Midwest/Western Great Lakes will be well northeast into Canada this
morning, while its trailing arctic cold front will be positioned
just off the Atlantic Seaboard to start the period. Behind this low
and the associated front, strong CAA on NW winds will be widespread
across the Great Lakes, Central Appalachians, and Mid-Atlantic
States, while a lagging but potent upper trough swings through the
Ohio Valley. The overlap of this upper trough and the post-frontal
NW flow will result in 3 areas of moderate to heavy snowfall today.

1) Great Lakes: CAA on the NW cyclonic flow will drop 850mb temps
to as low as -20C (or slightly colder). This cold air moving across
the lakes will lead to very steep lapse rates and rising inversion
depths despite lake surface temperatures that are generally +5C or
less according to GLERL. This will support efficient lake effect
snow (LES) in the favored W/NW snow belts, and although the
duration of any single bands may be modest due to the movement of
the mid- level trough, heavy snow rates in excess of 1"/hr are
possible (30-50%) within any LES bands. The heaviest accumulations
are likely across the Tug Hill Plateau and then down towards
Syracuse, where WPC probabilities are high (>70%) for at least 4
inches of snow, with locally more than 8 inches possible.

2) Central Appalachians: The persistent NW flow will generally
result in a drying column across the area. However, as the mid-
level trough swings overhead, it will briefly provide some
additional synoptic ascent through height falls/PVA, overlapping
favorable upslope flow into the terrain to produce periods of
moderate to heavy snow. The nature of this snow may be more snow
"showery" that continuous, limiting accumulations overall. However,
snowfall rates may at times reach 1"/hr (10-30% chance) leading to
locally as much as 4 inches of snow (10-30% chance) in the higher
terrain of WV and into the Laurel Highlands of PA.

3) Ohio Valley to the Mid-Atlantic: As the mid-level trough swings
overhead this aftn/eve, it will likely encourage some bubbling of
convective snow showers and isolated snow squalls across the
region. Lapse rates become impressively steep beneath this trough,
and there will be just enough moisture to generate numerous
convective snow showers which will move rapidly east through the
evening. The SnSq parameter is high for OH/WV/PA, and lesser due to
drier air farther east. While snow squalls can't be ruled out,
this is more likely to manifest as scattered to numerous convective snow showers across the area. Accumulation from these will be minimal,
but brief heavy snow rates and gusty winds could cause rapid
changes in visibility and hazardous driving later today.

The probability for significant icing across the country is less than 10%.

Weiss

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

FOUS11 KWBC 180619
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
219 AM EDT Wed Mar 18 2026

Valid 12Z Wed Mar 18 2026 - 12Z Sat Mar 21 2026

...Upper Midwest to the Northeast... Days 1-2...

Generally quiet winter weather encompasses the CONUS the next
several days as flat and fast flow keep systems progressive and
weak. Within this regime, multiple weak shortwaves traversing WNW
to ESE from the Northern Plains into the Mid-Atlantic and New
England will bring brief periods of light snow and mixed
sleet/freezing rain. In general, this will produce only minor
impacts and no significant snowfall. However, even light freezing
rain can be problematic to travel, so although WPC probabilities
for even 0.1" of ice are less than 5%, some light freezing rain
above 0.01" is likely (>70%) D1 for Wisconsin and lower Michigan,
and again D2 for far southern Michigan into Indiana/Ohio, which
could create travel difficulties due to icy roads.

Weiss


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

FOUS11 KWBC 190611
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
211 AM EDT Thu Mar 19 2026

Valid 12Z Thu Mar 19 2026 - 12Z Sun Mar 22 2026

...Upper Great Lakes to the Northeast... Days 1-3...

Thanks to a dome of upper-level ridging firmly entrenched over
the West and northerly low-level winds over the Mid-South all but
cutting off Gulf moisture, a quiet pattern with respect to heavy
snow and icing will continue. The lone cases where light snow
accumulations are anticipated are across the Upper Great Lakes and
Northeast as Canadian clipper systems race across the southern
tier of the country and occasional pass through. A clipper over
Ontario will direct a warm front through the Northeast with minor
snowfall totals (generally a coating-2", with local 2-3" in the
Adirondacks and White Mountains) through Thursday. As that system
exits over Atlantic Canada, a more organized clipper will be
tracking towards Lake Superior. Light snow will ensue along the
warm front over the U.P. of MI, Thursday night and into Friday AM,
then race over northern NY and northern New England Friday
afternoon and evening.

There are some hints in AI guidance (EC-AIFS most notably) that the
clipper could strengthen by the time it reaches Downeast Maine
early Saturday morning. This could lead to locally heavier snowfall
in the Greens, Whites, and northern ME on Saturday. At the moment,
WPC probabilities shows low chances (10-30%) chances for snowfall

4" in northern ME with most snowfall generally under 3". But this

will be closely monitored given the generally good performance of
the EC-AIFS for much of the cold season.

The chances for significant icing across the CONUS is less than 10 percent.

Mullinax

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

FOUS11 KWBC 200701
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
301 AM EDT Fri Mar 20 2026

Valid 12Z Fri Mar 20 2026 - 12Z Mon Mar 23 2026

...Upper Great Lakes to the Northeast... Days 1-3...

The first in a series of clipper systems will produce periods of
snow across northern New York and northern New England today. Low-
level WAA ahead of the clipper will support periods of snow, even
down to the valley floors in northern New England. However,
snowfall rates and elevation will play critical roles in snowfall accumulations. Most notably, the Adirondacks, Green, and White
Mountains are most favored for >1"/hr snowfall rates. WPC
probabilities depict localized moderate probabilities (40-60%) for
snowfall totals >4" with the peaks of these mountain ranges
(including Mt. Washington) sporting low chances (10-30%) for
snowfall accumulations as high as 6". Otherwise, most elevations
below 1,000ft are likely to see anywhere from a coating to as much
as 3". The WSSI does depict some Minor Impact potential,
particularly in the Adirondacks and bordering the St. Lawrence
River in NY's North Country. Snow will taper off across northern
New England by Friday night.

As this clipper exits to the east Saturday morning, the next
clipper system is already making its way towards the Upper Great
Lakes. There remains a decent amount of model spread in the
amplitude and progression of this clipper, largely because it is
essentially an unorganized cluster of sheared 500mb vort maxima
tracking over the northern Great Lakes and Northeast. There will be
sufficient upper-level ascent thanks to the left-exit region of a
500mb jet streak will accompany the clipper. There is also
agreement on model guidance on healthy 850-700mb WAA via WSWrly
flow that collides with sufficiently cold boundary layer
temperatures over northern NY and the rest of northern New
England. However, guidance is not yet in agreement on where the
strongest 850-700mb FGEN takes shape, and as a result, disagree on
the placement of the QPF axis to the north of the storm track. WPC
Day 3 cluster analysis shows the departing trough over Nova Scotia
and the depth of the primary 500mb shortwave trough over the Upper
Midwest are the most sensitive factors in determining what this
clipper ultimately produces, and because of the notably shorter
wavelengths, confidence in where the heaviest snowfall will occur
is not clear out to Day 3.

So what we do know-- It is late March and elevation matters a ton.
However you slice it across deterministic guidance or
probabilistic guidance, the Adirondacks, Green, Whites, and
Berkshires are most favored for accumulating snowfall. Even as far
west as the MI U.P. and MN Arrowhead, snowfall totals approaching
4" are possible. WPC probabilities show low-to-moderate chances
(30-50%) for snowfall totals >4" in the Hurons of the MI U.P.
between Saturday night and through Sunday. Farther east, the

2,000ft elevations in the Adirondacks, Greens, and Whites sport

moderate chances (40-60%) for snowfall totals >8" on Sunday. Below
1,000ft, probabilities for snowfall amounts >4" are low (10-30%)
with most accumulations less than 4" expected at this time. WPC's
WSSI-P depicts moderate chances (40-60%) for Minor Impacts in the
MN Arrowhead to much of northern MI due to a combination of snow
and ice (WPC probabilities show low-to-moderate chances, or 30-50%,
for ice accumulations of at least one-hundreth of an inch) late
Saturday into early Sunday. Minor probabilities are highest in
northern New England where moderate probabilities (40-60%) are
present throughout the northern Appalachians. In fact, some
localized 40-50% probabilities for Moderate Impacts are shown
across south-central and Downeast Maine.


The chances for significant icing across the CONUS is less than 10
percent.


Mullinax

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

FOUS11 KWBC 210715
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
315 AM EDT Sat Mar 21 2026

Valid 12Z Sat Mar 21 2026 - 12Z Tue Mar 24 2026

...Northeast...
Days 1-2...

A clipper system will move southeast out of central Canada and into
the Northeast this weekend. Snow on the leading edge of the
precipitation shield will move into upstate New York this evening,
then spread across New England tonight. The snow will be
characterized by warm advection. With a high sun angle and
plentiful warm air over much of the eastern half of the country,
the warm air will move into New York and southern New England,
resulting in a changeover to rain on Sunday over much of upstate
New York and into southern New England. Meanwhile, over most of
northern New England, the predominant precipitation type remains as
snow as the back edge of the precipitation quickly pushes east
across New England.

The southwesterly flow of warm air will be uplifted by the terrain
of the Adirondacks, Green, and White Mountains. Here, the
combination of upslope and cooler temperatures at higher
elevations will support multiple inches of snow. The heaviest snow
will fall between early Sunday morning and Sunday evening. In the
valleys, warmer temperatures, high sun angle, and snow mostly
falling during the day should all work to keep snow totals much
lower than the adjacent mountains, though still reaching into
advisory criteria. Where snow rates remain lighter, accumulations
during the day should be greatly tempered, and largely confined to
grassy areas.

WPC snowfall probabilities for the storm total snow over 4 inches
are high (over 70%) from the northern Adirondacks east across the
northern Greens of Vermont, northern Whites of New Hampshire, and
much of southern Maine. For much of northern New Hampshire and
western Maine, those probabilities are above 90% for 4 inches and
over 70% for 8 inches. As typical with compact storms, the exact
longevity and intensity of any internal heavy snow bands will
dictate where the highest snowfall totals are observed.

By D3/Monday, a secondary coastal low is expected to form south of
Long Island. The precipitation shield will be narrow and focus
across southern New England, where temperatures will be warm enough
for mostly (or entirely) rain. Thus, the chances for impactful
snow on Monday anywhere in the Northeast continue to decrease.

The chances for significant icing across the CONUS is less than 10
percent.


Wegman



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

FOUS11 KWBC 220714
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
314 AM EDT Sun Mar 22 2026

Valid 12Z Sun Mar 22 2026 - 12Z Wed Mar 25 2026

...Northeast... Days 1-2...

Snow has begun falling across the northern Appalachians and
northern New England this morning as 850-700mb WAA aloft overruns a
boundary layer sufficiently cold enough to support snow. Snowfall
rates around 1"/hr are likely over the Green and White Mountains
this morning, where the combination of heavy rates and elevation
will support accumulating snowfall. Given the snow is unfolding
during the day, and boundary layer temperatures are more marginal
in the valleys, snowfall will be tougher to accumulate but still
cause some minor accumulations in the Champlain Valley and along
coastal Maine today. Snowfall will gradually taper off by Sunday
evening with light snowfall over Downeast Maine still unfolding.
There will still be cases where light snow ensues over northern New
England Sunday night and into Monday morning as a strengthening
500mb trough approaches from the west and low-level easterly flow
directs some Atlantic moisture into the region. Additional light
snow accumulations of a coating to 3 inches are possible through Monday.

48-hour WPC probabilities show high chances (>70%) for >4" of
snowfall throughout southern Maine, the White and Green Mountains,
and the peaks of the Adirondacks. In the Green and White Mountains,
elevations above 2,000ft are likely to see snowfall totals range
between 8-12", with some localized peaks (such as Mount Washington)
potentially receiving over a foot of snow. The WSSI primarily shows
Minor Impacts (winter driving conditions; use caution) with locally
some Moderate Impacts (hazardous travel conditions) possible,
particularly in passes and complex terrain.

...Washington Cascades & Olympics... Day 3...

A Pacific storm system will direct a plume of moisture at the
Pacific Northwest Monday night and into Tuesday that leads to
higher elevation snowfall. Snow levels initially starting out
between 4,000-5,000ft Monday night and early Tuesday will drop to
as low as 2,500ft in the Olympics and 3,000ft in the northern WA
Cascades. WPC probabilities show moderate-to-high chances (50-80%)
for snowfall totals >4" above 3,000ft in the Olympics and above
4,000ft in the WA Cascades north of I-90. At this moment,
Snoqualmie and Stevens Passes show low chances (<20%) for
accumulating snowfall >4", but some minor accumulations late
Tuesday into Tuesday night are possible.


The chances for significant ice across the CONUS is less than
10 percent.


Mullinax

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

FOUS11 KWBC 230726
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
326 AM EDT Mon Mar 23 2026

Valid 12Z Mon Mar 23 2026 - 12Z Thu Mar 26 2026

...Northern New England... Day 1...

An inverted trough, extending back from the departing storm system
responsible for rounds of snow yesterday, will linger across
northern New England today. With sufficient low-level moisture off
the Atlantic and vertical ascent supplied by an approaching
shortwave trough to the west, periods of snow will continue over
the White Mountains. Some light snow is possible below 1,000ft, but
given the snow is occurring during daytime hours, snow will
struggle to accumulate on paved surfaces. WPC probabilities depict moderate-to-high chances (50-70%) for additional snowfall
accumulations >4" in the White Mountains, which included Mount
Washington. Otherwise, any additional snowfall accumulations below
2,000ft are likely to range between a coating-3".

...Washington Cascades & Olympics... Days 1-3...

A strong and meandering closed upper low in the Gulf of Alaska will
direct a storm system forming on its southern flank at British
Columbia the first half of the week. With the Gulf of Alaska low
slow to move east and low level ridging in place off the southern
CA coast, low-level SWrly flow will supply a narrow corridor of
Pacific moisture into the Pacific Northwest Monday night and
through both Tuesday and into Wednesday. Snow levels will generally
reside above 3,000ft through Tuesday, but a cold frontal passage
and falling 700-500mb heights Tuesday night will cause snow levels
to dip to as low as 2,000ft by Wednesday. Still, the cold air in
wake of the cold frontal passage is not particularly cold, and the
best moisture advection will have already concluded by Wednesday.
This is likely to cause periods of mountain snow on Wednesday in
the Olympics and Cascades to as low as 2,000ft, but rates will not
be overly heavy even through Wednesday night.

WPC probabilities for >4" of snow are moderate-to-high (50-80%) for
elevations above 4,000ft north of I-90. Stevens Pass sports
moderate-to-high chances (50-80%) for snowfall totals >4" through
Wednesday night, while Snoqualmie Pass has moderate chances
(40-60%). Both passes sport low-to-moderate chances (20-40%) for
snowfall totals >8", so some locally hazardous travel conditions
are possible at pass level, but the heavier totals surpassing 8"
will likely be found at higher elevations for this event.

The chances for significant ice across the CONUS is less than 10 percent.

Mullinax

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

FOUS11 KWBC 240711
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
311 AM EDT Tue Mar 24 2026

Valid 12Z Tue Mar 24 2026 - 12Z Fri Mar 27 2026

...Washington Cascades & Olympics... Days 1-2...

A strong and meandering closed upper low in the Gulf of Alaska
will direct a storm system forming on its southern flank at British
Columbia the first half of the week. With the Gulf of Alaska low
slow to move east and low level ridging in place off the southern
CA coast, low- level SWrly flow will supply a narrow corridor of
Pacific moisture into the Pacific Northwest today and into Wednesday.
Snow levels will generally reside above 3,000ft today, but a cold
frontal passage and falling 700-500mb heights Tuesday night will
cause snow levels to dip to as low as 2,000ft by Wednesday. Still,
the cold air in wake of the cold frontal passage is not
particularly cold, and the best moisture advection will have
already concluded by Wednesday. This is likely to cause periods of
mountain snow on Wednesday in the Olympics and Cascades to as low
as 2,000ft, but rates will not be overly heavy even through
Wednesday night.

WPC probabilities for >4" of snow are high (>70%) for elevations
above 4,000ft north of I-90. Stevens Pass sports high chances

70%) for snowfall totals >4" through Wednesday night, while

Snoqualmie Pass has moderate chances (50-70%). Stevens Pass poses
the slightly better odds for snowfall totals >8", ranging between
30-50%. Some locally hazardous travel conditions are possible at
pass level, but the heavier totals surpassing 8" will likely be
found at higher and more remote elevations.

...Northern Maine... Days 2-3...

Starting Wednesday night, sheared lobes of 500mb vorticity racing
over the northern Great Lakes will generate PVA over northern New
England at the same time that low-level SWrly flow results in low-
level WAA and increased moisture content. Weak high pressure over
Quebec and sufficiently cold enough air over Maine will support
periods of snow over northern Maine with some minor icing possible
in central ME. As the first disturbance races east, a second 500mb
shortwave trough will spawn a second low over the northern Mid-
Atlantic Thursday evening. Periods of snow may envelope northern
Maine Thursday night as a cold front races south and forces
boundary layer temperatures to crash below freezing. There remains
some model spread in solutions regarding this second round of snow
Thursday night, so confidence in the snowfall placement and amounts
for the second round of snow is lower. At the moment, 48-hour WPC
probabilities show low chances (10-30%) for snowfall totals >4"
along the ME/Quebec border.


The chances for significant ice across the CONUS is less than
10 percent.


Mullinax

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

FOUS11 KWBC 280647
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
247 AM EDT Sat Mar 28 2026

Valid 12Z Sat Mar 28 2026 - 12Z Tue Mar 31 2026

...Pacific Northwest/Northern Rockies... Days 2-3...

A closed low south of the Gulf of Alaska will continue
southeastward today and slowly weaken into a positively-tilted
upper trough as its cold front moves through WA/OR on Sunday.
Despite some injection of mid-latitude Pacific moisture, the system
will be progressive and QPF will be limited. Snow levels will be
on the lower side -- 2500-4000ft in the Cascades before lowering
further behind the front to 1500-3000ft. This will bring some snow
to the passes and probabilities for at least 6 inches are at least
50% above about 3000ft or so for the northern Cascades.

Farther east, moisture will stream into the northern Rockies and
eventually into northern/northwestern Wyoming Sunday evening
through Monday and overnight into very early Tuesday, ending from west/northwest to east/southeast. Amounts will again be generally
light, with probabilities of at least 6 inches at least 50% above
about 5000ft in ID/MT but above 9000-10,000ft in WY.

Front end of the precip shield advancing across the Northern
Plains could support some light icing over northern ND early Monday
with generally a few hundredths of an inch possible.

The probability of significant icing across the CONUS for days 1-3
is less than 10%.

Fracasso


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

FOUS11 KWBC 290701
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
301 AM EDT Sun Mar 29 2026

Valid 12Z Sun Mar 29 2026 - 12Z Wed Apr 01 2026

...Pacific Northwest/Northern Rockies... Days 1-2...

A sharp positively-tilted upper trough just west of Vancouver this
morning will continue to push eastward as its cold front moves
through WA/OR today. Despite some infusion of mid-latitude Pacific
moisture, the system will weaken a bit and remain progressive,
limiting QPF amounts. Lower snow levels around 2500-4000ft in the
Cascades this morning will lower behind the cold front to
1500-3000ft. This will bring some snow to the passes and
probabilities for at least 6 inches are at least 50% above about
3000-3500ft or so for the Washington Cascades.

Farther east, moisture will stream into the northern Rockies late
this afternoon/tonight and eventually into Wyoming late Monday into
Tuesday, ending from west/northwest to east/southeast as the cold
front moves to the east quicker than it sinks to the south. Amounts
will again be generally light, but northwestern Montana may see
totals in excess of a foot around Glacier NP (50-80% chance). In
general, probabilities of at least 6 inches of snow are at least
50% above about 5000ft in ID/MT but above 9000-10,000ft in WY. The
Absarokas in southern MT into northwest WY may also see slightly
higher totals due to some local surface convergence.

Front end of the precip shield advancing across the Northern
Plains could support some light icing (generally a few hundredths
of an inch) over northern ND early Monday then into northeastern MN
and perhaps the U.P. of Michigan as the system redevelops over the
Plains/Corn Belt.

...Northern New England... Day 3...

The system over the Great Lakes on Monday (above) will move into
the Northeast on Tuesday. Marginally cold temperatures will be
limited to northern NY/VT/NH and much of interior Maine as
precipitation advances into the region Tuesday morning along and
ahead of a surface warm front. With the main area of low pressure
quite far to the west early Tuesday (WI or into Lower MI), cold air
may hang on longer in sheltered areas over northern New England
which would support some light snow to start but then more likely a
period of freezing rain. AI guidance suggests colder temperatures
than the dynamical models Tuesday night into Wednesday morning,
hinting at at least non-trivial amounts of freezing rain (though
the better signal lies across Canada near/northeast of Ottawa). For
now, kept amounts to around a tenth of an inch but with the
potential to trend higher in the next couple of days. WPC
probabilities for at least 0.10" icing are >30% over northwestern Maine.

...Sierra Nevada to the CO Rockies... Day 3...

Combination of the tail-end of the Pacific Northwest/northern
Rockies system today/Monday and an incoming weak shortwave out of
the Pacific Tuesday afternoon will bring some light to perhaps
modest snow to the Sierra and CO Rockies and dotted across the
Great Basin in between. Snow levels will be high -- 8000-9000ft --
with WPC probabilities for at least 6 inches of snow between about
40-80% above 9000-10,000ft.

The probability of significant icing across the CONUS for days 1-3
is less than 10%.

Fracasso

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

FOUS11 KWBC 300742
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
342 AM EDT Mon Mar 30 2026

Valid 12Z Mon Mar 30 2026 - 12Z Thu Apr 02 2026

...Northern Rockies... Day 1...

Cold front moving eastward through the Northern Rockies will
continue to bring generally light snow to the central ID ranges
into the Absarokas and Bighorns today. The snow associated with
this system will be supplanted by incoming moisture from a Pacific
system. Through 12Z Tue, WPC probabilities of an additional 6
inches of snow are >50% over the Absarokas.

...Sierra Nevada to the CO Rockies... Days 2-3...

An incoming shortwave out of the Pacific Tuesday afternoon will
bring some light to perhaps modest snow to the Sierra, Wasatch,
Uintas, and CO Rockies as it zips eastward. Snow levels will be
high (8000-9000ft though falling ~1000ft as the trough moves
through) with WPC probabilities for at least 8 inches of snow are
at least 50% above 7500ft (Sierra) to 10,000ft (CO). Totals in the
CO Rockies may eclipses a foot above 11,000ft.

...Pacific Northwest... Day 3...

Next system out of the Gulf of Alaska will barrel toward the
Pacific Northwest on Wednesday, bringing a more substantial influx
of moisture ahead of its rather robust cold front. Trailing mid-
level low will sustain modest snowfall totals into the Cascades and
points eastward to the northern Rockies yet again. The focus may
be the southern WA Cascades, OR Cascades, central ID ranges, and
NorCal ranges including the northern Sierra as the cold front
reaches there by the end of this forecast period. Snow levels will
range from 4000-7000ft (north to south) ahead of the front, then
fall to 2500-6000ft post-FROPA. WPC probabilities for at least 8
inches of snow are >50% above 5000ft or so in the OR Cascades and
7000ft in NorCal and across the northern Great Basin.

...Northern New England... Day 2...

The system exiting the High Plains today will move into the
Northeast on Tuesday. Marginally cold temperatures will be limited
to northern NY/VT/NH and much of interior Maine as precipitation
advances into the region Tuesday morning along and ahead of a
surface warm front. With the main area of low pressure quite far to
the west early Tuesday (WI or into Lower MI), cold air may hang on
longer in sheltered areas over northern New England which would
support some light snow to start but then more likely a period of
freezing rain will materialize as southwesterly flow aloft advects
in some warmer air within the upper portion of the boundary layer
into the mid-levels. With the surface low track potentially no
farther north than the VT-NH/Quebec border, this could prolong the
freezing rain threat for much of the event. WPC probabilities for

0.25" of ice accumulation are 10-30% across northwest ME.

...Upper Midwest/Corn Belt/Western Great Lakes... Day 3...

System exiting the Rockies Wednesday will lift to the northeast
toward the Great Lakes. With a generous fetch of moisture from the
Gulf northward and a marginally but sufficiently cold thermal
profile north of about I-80, an expanding area of
snow/sleet/freezing rain is increasingly likely for much of the
region overnight Wednesday through Thursday (continuing beyond this
forecast period). Uncertainty is high, compounded by the spread in
ptypes from the models/ensembles. For now, through 12Z Thursday,
expect a west-to-east swath of snow farthest to the north (SD
eastward to WI and MI) and sleet/freezing rain just to the south
(Iowa eastward through southern WI into Lower MI). Again, these
areas may shift over the next couple of days depending on how the
storm evolves over/east of the Rockies. Just through 12Z Thursday,
WPC probabilities for at least 4 inches of snow are 10-40% from SD
eastward to about northern WI. For freezing rain, probabilities for
at least 0.10" icing through 12Z Thursday are 10-50% over southern
WI and into central Lower MI. The probabilistic WSSI is already
showing 20-40% chance of moderate impacts day 3, and even higher
beyond. See our extended forecast discussion (PMDEPD) for more
information.

Fracasso

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

FOUS11 KWBC 310749
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
349 AM EDT Tue Mar 31 2026

Valid 12Z Tue Mar 31 2026 - 12Z Fri Apr 03 2026

...Potentially impactful mixed precipitation event increasingly
likely for the Upper Midwest into the Great Lakes Thursday...

...Sierra Nevada to the Rockies... Days 1-2...

An incoming shortwave out of the Pacific this afternoon will bring
some light to perhaps modest snow to the Sierra Nevada, Wasatch,
Uintas, and CO Rockies as it zips eastward. To the north, lingering
moisture along a stationary surface boundary will maintain light
snow over the ID ranges into Wyoming with additional accumulation.
Snow levels will be high (8000-9000ft to the south, though falling
~1000ft as the trough moves through) with WPC probabilities for at
least 8 inches of snow are at least 50% above 7500ft (Sierra) to
10,000ft (CO). Totals in the CO Rockies may eclipses a foot above
11,000ft. Over ID into WY, WPC probabilities for at least 8 inches
of snow are at least 50% above 8000ft.

...Pacific Northwest to the Northern Rockies... Days 2-3...

A powerful closed upper-low diving southward from the Gulf of
Alaska will be the catalyst for renewed mountain snow in the
Olympics, Cascades, the Salmon/Siskiyou of northern CA, and as far
east as the Blue Mountains Wednesday afternoon and continuing
through Thursday. The approaching 850-500mb layer heights
associated with the closed low are below the 10th percentile and
snow levels will be able to drop as low as 2,000ft Wednesday night
in the Olympics, Cascades, and even as far south as the Siskiyou. A
steady stream of Pacific moisture embedded within SWrly mean layer
flow, suitable for upslope enhancement as well, will also favor
locally heavy snowfall rates in these ranges. Drier air should move
in on the backside of the closed low by Thursday afternoon,
although lingering westerly low-level winds should support light-
to-moderate snow in the Cascades for the remainder of the day on
Thursday with all precipitation ending by early Friday morning west
of the Divide.

To the east, snow will start overnight tomorrow night and continue
through this forecast period (12Z Fri) over Montana. With a closed
low track from the WA/OR border ESE across central ID into central
WY, snow will maximize over the Blue Mountains, Bitterroots,
Absarokas, Tetons and into the Bighorns. The western MT ranges will
also see moderate snow totals closer to the 700mb low and old
triple point surface low.

WPC 48-hour probabilities for at least 12 inches of snow are high

70%) in the OR Cascades above 4,000ft with at least moderate

chances (>50%) for snowfall totals >8" at elevations >3,000ft. The
WA Cascades will see lesser snowfall totals than their OR neighbors
given the best Pacific moisture plume will reside farther south,
but several inches of snow at pass level (Snoqualmie and Stevens)
are expected. To the east, WPC probabilities for at least 12 inches
of snow are at least 50% above 7000ft or so.

...Northern New York and New England... Days 1&3...

A lingering front will become the focus for organized
precipitation as a series of low-amplitude southern stream waves
interact with deepening moisture. Light precipitation will spread
across the region today with the first wave, followed by heavier
precipitation tonight as a following wave strengthens ahead of a
more amplified northern stream wave moving across Quebec. While
southwesterly flow aloft advects warmer air into the mid-levels, a
shallow but stubborn layer of sub-freezing air is expected to
remain entrenched across northern New England. Forecast soundings
support mostly snow across far northern Maine, while areas farther
south, including areas as far south as Downeast Maine, may see snow transitioning to accumulating ice. Guidance continues to indicate
that northwestern Maine is the area mostly likely to be impacted
with heavier ice accumulations. WPC probabilities of at least a
tenth of an inch of ice are 30-50% over the Central Highlands and
northern White Mountains. Northern Aroostook County has the highest
chance of staying all snow, with WPC probabilities of at least 4
inches 50-90%.

Following a brief dry period Wednesday night, the threat for
wintry weather is forecast to return to the region on Thursday as
the system detailed below lifts toward the Great Lakes -- bringing
moisture back into the region as cold high pressure remains
anchored to the north. For Day 3, the setup again would favor all
snow over far northern Maine then quickly transitioning to sleet
and freezing rain for the Central Highlands southwestward through
much of northern NH, the Northeast Kingdom of Vermont, and the
northern Adirondacks. WPC probabilities for at least 4 inches of
snow are 30-50% along the northern Maine border with Canada (North
Woods area). For freezing rain, WPC probabilities for at least a
tenth of an inch of ice are at least 30% over the northern CT River Valley/Northeast Kingdom into central/northern NH and northwestern Maine.

...Upper Midwest/Corn Belt/Western Great Lakes... Days 2-3...

An amplified shortwave exiting the Rockies Wednesday night will
lift toward the Great Lakes, directing a deep plume of Gulf
moisture to the north. As precipitation blossoms across the region
on Thursday, a sharp thermal gradient north of the I-80 corridor
will support a broad swath of wintry weather, topped by a west-
east band of heavy snow and bordered to the south by a corridor of
sleet and freezing rain, with significant ice accumulations
possible. Uncertainty remains high overall due to a shifting storm
track in the models (northwest trend since yesterday) and ptype
uncertainty through the storm evolution as many areas will see a
transition from snow or sleet to freezing rain and perhaps just
rain. Though precipitation may be still ongoing at the end of this
forecast period (12Z Fri), the heaviest will likely be on Thursday.

Through 12Z Friday, WPC probabilities for at least 4 inches of
snow are at least 50 percent from portions of the eastern Dakotas
through much of central to northeastern MN (especially the
Arrowhead), northern WI, and into the western U.P. of Michigan. The
highest probabilities of snowfall in excess of 8 inches lies over
the Arrowhead (30-60% chance).

The freezing rain may be significant within a broad region that
may see at least some icing; namely, SD through MN and WI to MI.
WPC probabilities for at least a tenth of an inch of ice are at
least 30% over much of Wisconsin into the U.P. and the northern 1/3
of Lower Michigan. Some areas could see in excess of 0.25" icing,
specifically central WI and northern Lower Michigan, but this is
subject to change with the storm track. The probability of Moderate
impacts per the WSSI-P are at least 40% in these areas.

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