Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
421 AM EDT Sat Nov 04 2023

Valid 12Z Sat Nov 04 2023 - 12Z Tue Nov 07 2023

...Northwest to Northern Rockies...
Days 1-3...
Upper troughing, onshore flow, and lowering snow levels can be
expected over the Northwest and northern Rockies through Tuesday
as a series of shortwave troughs cross the region within strong a
strong zonal jet. Snow levels begin today around 10,000ft, but
drop to 5000-6000ft from west to east tonight through Sunday. Only
the highest peaks get snow today, with moderate Day 2 snow probs
for >6" over the Absaroka and Wind River Ranges. The final pair of
shortwave troughs for the series reach the PacNW coast Monday and
Monday night with positively-tilted troughing over the Northwest
by 12Z Tuesday. Left-exit jet dynamics and strong onshore flow
yield 30 to 60% Day 3 probabilities of mountain snowfall >6"
through the Cascades, the Sawtooth and Salmon River Mtns in ID and
again in western WY.


...Northern North Dakota into far Northwestern Minnesota...
Days 1/2...
Low-level isentropic ascent atop a shallow subfreezing airmass
should allow some freezing rain along the North Dakota-Canadian
border Saturday night into Sunday. Day 2 ice probabilities are
10-30% for >0.10" along the NC/Manitoba border west of the Red
River of the North.


Jackson