FOUS11 KWBC 240800
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Tue Feb 24 2026

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

...Northern and Central Rockies... Days 1-2...

Positively tilted trough off the WA/OR coast spins off a cutoff low
halfway to Hawaii tonight. South of the trough axis is an
atmospheric river flowing into northern CA and OR. Snow levels over
the OR Cascades exceed 7000ft, which is not really impactful.
However, this ample moisture overspreads central ID/western MY
where snow levels are 5000-6000ft and over western WY where snow
levels rise from 6000 to 7000ft which is impactful. Day 1 snow
probs for >8" across this terrain is over 50% and is 50-80% for
>24" over the Tetons and Wind Rivers.

The snow focus shifts south down the Rockies into northern CO
Wednesday, but it's transient in a powerful westerly jet and
ridging off the coast (but east of the cutoff low) redirects
Pacific moisture to keep it offshore, cutting drastically on the
precip rates (which is unfortunate for CO and their snow drought).
Day 2 snow probs for >8" are 30-50% for the Wind Rivers/Tetons, and
40-70% in the Park Range, western slopes of the Front Range, and
down through ranges in central CO. Precip cuts off entirely over CO
Wednesday night.

...Washington Cascades... Days 2/3...

Ridging offshore from the low halfway to Hawaii allows the next
wave to shift south into the Gulf of Alaska Wednesday night. Broad
cyclonic flow brings north Pacific moisture into WA Wednesday night
through THursday night. Snow levels around 2500ft allow moderate
snowfall at pass level. Day 2/2 snow probs for >6" are both 30-60%
in the northern WA Cascades.

...Great Lakes and Northeast... Days 1/2...

An Alberta Clipper will shift ESE from northern MN through the U.P.
of MI today, the L.P. tonight, before crossing the Northeast
Wednesday. Warm air advection ahead of the surface low will be
into an Arctic airmass with plenty of DGZ available for snow
crystal growth. Moderate to heavy snow rates of 1-2"/hr from Lake
Michigan enhancement can be expected in the east-central U.P.
where Day 1 snow probs for >6" are 50-70%. Brief LES trails the
clipper tonight off Lake Superior, then spreading across the Great
Lakes Wednesday. Day 1.5 snow probs for >6" are 30-50% in the
Keweenaw Peninsula and eastern U.P. north shore, around 80% in the
Tug Hill, and 30-60% off Lake Erie across the hills in southwest
NY state. Elsewhere in the Northeast, expect 1-2" of synoptic snow.

...Northern Plains through Midwest and Mid-Atlantic... Days 2/3...

The next clipper crosses the northern Plains Wednesday, pushing
across the Midwest Wednesday night, and the northern Mid-Atlantic.
The GFS still remains the farthest north/strongest physical
deterministic guidance with this clipper, though the 00Z EC-AIFS is
in somewhat agreement with the GFS Day 3 over the central
Appalachians and Mid-Atlantic. Overall the trend has been south and
less wintry. As of now the only snow probs >4" with this clipper
are over the Northeast where 00Z guidance is generally less keen on
having any precip.

Only light icing potential is present with either of the two clippers.

Jackson

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