980  
FOUS11 KWBC 150848  
QPFHSD  
 
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
348 AM EST MON DEC 15 2025  
 
VALID 12Z MON DEC 15 2025 - 12Z THU DEC 18 2025  
 
   
..GREAT LAKES
 
 
DAY 1...  
 
SOME LAKE ENHANCED SNOW FOR MICHIGAN THIS MORNING AHEAD OF A  
SHORTWAVE TROUGH CURRENTLY OVER THE ARROWHEAD OF MN. THE GREATER  
IMPACTS ARE ON THE EASTERN GREAT LAKES WHERE FLOW IS ALREADY  
BACKING WESTERLY. BRIEF SINGLE-BANDING LES OCCURS THIS AFTERNOON  
OFF LAKE ERIE INTO THE SOUTH TOWNS OF BUFFALO WHERE DAY 1 PWPF FOR  
>4" ARE AROUND 60%. THE GREATER LES FORMATION IS THIS EVENING WITH  
SINGLE-BANDING INTO THE TUG HILL PLATEAU THROUGH THE NIGHT BEFORE  
TAPERING OFF TUESDAY MORNING IN NOTABLE WARM AIR ADVECTION. THE  
SATURATED LAYER GETS INTO THE DGZ AND THE FLOW IS FAIRLY STEADY  
STATE, SO DECENT SNOWS ARE FORECAST. DAY 1 PWPF FOR >8" ARE AROUND  
80% FOR THE TUG HILL.  
 
   
..CASCADES AND NORTHERN ROCKIES
 
 
DAYS 1-3...  
 
A LEAD WARM ATMOSPHERIC RIVER (AR) WILL BRING MOSTLY RAIN TO THE  
PACNW THROUGH EARLY AFTERNOON WITH VERY HIGH SNOW LEVELS AROUND  
9000FT. A SHORTWAVE TROUGH BRINGS A COLD FRONT THROUGH BY THIS  
EVENING WHICH WILL LOWER SNOW LEVELS THIS EVENING AMID LIGHTER QPF  
TO AROUND 4000FT IN WA 5000FT IN NORTHERN OR. DAY 1 PWPF FOR >8"  
ARE LIMITED TO THE HIGHER WA CASCADES.  
 
SNOW LEVELS RISE BACK TO 5000FT IN WA AND 6000FT IN OR TUESDAY AS  
THE NEXT MOISTURE SURGE PUSHES INLAND. HOWEVER, A SHARPER SHORTWAVE  
TROUGH AXIS PUSHES ACROSS THE CASCADES BY 12Z WEDNESDAY. THIS  
POTENT COLD FRONT BRINGS A SHARP DROP IN SNOW LEVELS AFTER 06Z  
WEDNESDAY TO AROUND 2000FT IN WA AND 4000FT IN OR. AGAIN, THE  
PRECIP RATES RAPIDLY DROP WITH THE SNOW LEVELS, BUT THERE SHOULD BE  
IMPACTFUL SNOW AT PASS LEVELS INCLUDING SNOQUALMIE. DAY 2.5 PWPF  
FOR >8" ARE OVER 80% FOR MOST OF THE WA CASCADES. LOW SNOW LEVELS  
AND PRECIP RATES PERSIST THEN THROUGH WEDNESDAY NIGHT.  
 
MOISTURE AND WINDY CONDITIONS WILL PROGRESS EASTWARD OVER THE  
NORTHERN ROCKIES THIS AFTERNOON AND MUCH MORE SO TUESDAY NIGHT.  
DAY 1.5 SNOW PROBS FOR >8" ARE 30-60% OVER THE NORTHWESTERN MT  
RANGES. DAY 2.5 SNOW PROBS FOR >8" ARE 50-80% OVER THE WESTERN MT,  
CENTRAL ID, AND NORTHWEST WY RANGES WITH RAPID DROPS IN SNOW  
LEVELS.  
 
THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.  
 
JACKSON  
 

 
 
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