Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
301 PM EDT Fri Oct 31 2025

Valid 00Z Sat Nov 01 2025 - 00Z Tue Nov 04 2025

...Northeast Terrain...
Day 1...

Low pressure over northern New England lifts north to the Gulf of
St. Lawrence tonight. Wrap around/northwesterly flow on the back
side will support moist upslope flow through the Adirondacks,
Greens, and Whites. Snow levels drop from around 2000ft to 1000ft
this evening allowing increasing coverage of elevation based snow
accumulation through early Saturday morning. Day 1 snow
probabilities for >4" are 20-60% above 1500ft over those ranges.


...Washington Cascades...
Days 1-2...

A longwave trough extending from a low over the Gulf of Alaska
directs is directing highly anomalous IVT topping 1,000 kg/m/s (and
PW up to 1.25") at the Pacific Northwest through Saturday
morning. Snow levels remain high in this atmospheric river, around
9000ft over the northern Cascades, until a shortwave trough passage
Saturday afternoon brings heights down. A rapid drop in snow level
to 3000-4000ft before snow tapers off Saturday night allows some
impactful snow. Day 1.5 WPC snow probabilities for >6" are 30-60%
above at least 5000ft.


The probability of significant ice across the CONUS is less than
10 percent.

Jackson