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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