FOUS11 KWBC 221931

QPFHSD



Probabilistic Heavy Snow and Icing Discussion

NWS Weather Prediction Center College Park MD

331 PM EDT Sun Mar 22 2026



Valid 00Z Mon Mar 23 2026 - 00Z Thu Mar 26 2026



...Northern New England... 

Day 1...



While the primary precipitation shield associated with a clipper

system crossing the Northeast is forecast to begin moving offshore

this evening, a secondary period of accumulating snow is expected

on Monday. An inverted trough, extending back from the departing

low, is forecast to develop and linger across eastern New England.

This feature will likely act to focus a north-south oriented band

of snow showers that could intensify late Monday as an 

intensifying shortwave and associated cold pool aloft pivot into 

the region from the west.



Given the added lift and some modest instability, localized heavier

bursts are possible, especially in northern New Hampshire and

western Maine where the inverted trough may align with favorable 

upslope flow. WPC probabilities indicate that an additional 2-4 

inches are possible with this band, with the highest probabilities 

(50-70+ percent) focused over the northern New Hampshire and 

western Maine mountains.



...Washington Cascades & Olympics...

Days 2-3...



A deepening storm lifting from the northeastern Pacific into

British Columbia will bring widespread moderate to heavy

precipitation into the region on Tuesday. However, the heaviest

precipitation rates are expected to coincide with relatively high

snow levels through Tuesday afternoon. Consequently, the bulk of

the significant accumulating snow (greater than 8 inches) will

remain above the major passes and confined to the higher peaks of

the Olympics and the northern Cascades.



As the front crosses the region late Tuesday and early Wednesday,

snow levels will begin to plunge toward 3,000 ft, but this cooling

will occur as the deepest moisture begins to shift east. However,

some of passes may see a period of rain changing to snow, impacting

travel. 





The chances for significant ice across the CONUS is less than 

10 percent. 



Pereira



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