FOUS11 KWBC 271855

QPFHSD



Probabilistic Heavy Snow and Icing Discussion

NWS Weather Prediction Center College Park MD

255 PM EDT Mon Oct 27 2025



Valid 00Z Tue Oct 28 2025 - 00Z Fri Oct 31 2025





...Northern/Central Rockies... 

Day 1...



Remaining moisture on the backside of a departing trough will 

wring out a few more inches of snow tonight over northwestern 

Montana where WPC probabilities for at least another 4 inches of 

snow after 00Z/28 are low (<40%). 





...Washington Cascades... 

Day 2...



A rapidly-deepening and strong closed low over the northeastern 

Pacific tonight/Tuesday will start to weaken as it moves ashore 

British Columbia tomorrow night. Mild temperatures will flood the 

Pacific Northwest ahead of the cold front with snow levels as high 

as 8000-9000ft 06Z Wednesday. However, snow levels will crash quite

smartly by 12Z as precipitation starts to decrease and end by the 

conclusion of day 2 (00Z/30). There will be a brief but impressive 

period of heavy snow invading lower elevations (down to about 

4500ft) which will impact the higher Washington Pass/SR-20. WPC 

probabilities for at least six inches of snow are >50% above about 

5000ft depending on how quickly snow levels fall coincident with 

moderate QPF. 





The probability of significant ice across the CONUS is less than 

10 percent.



Fracasso







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