476  
FOUS11 KWBC 172101  
QPFHSD  
 
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
401 PM EST MON NOV 17 2025  
 
VALID 00Z TUE NOV 18 2025 - 00Z FRI NOV 21 2025  
 
   
..SOUTHERN MINNESOTA INTO CENTRAL WISCONSIN
 
 
DAY 1...  
 
MID-LEVEL LOW PRESSURE OVER THE NEBRASKA PANHANDLE THIS AFTERNOON  
SHIFTS EAST TO IOWA TONIGHT AND TO NORTHERN INDIANA TUESDAY.  
DYNAMICS WITH THIS SYSTEM ARE SUFFICIENT TO CREATE LOCALLY HEAVY  
DEFORMATION ZONE BANDS WRAPPING AROUND THE NORTH SIDE WITH ENOUGH  
DYNAMIC COOLING TO OVERCOME THE MARGINAL THERMAL ENVIRONMENT AND  
CAUSE SNOW ACCUMULATIONS OVERNIGHT THROUGH TUESDAY MORNING. THIS  
WOULD BE IN A NARROW STRIPE OVER SOUTHERN MN (SOUTH OF THE TWIN  
CITIES) INTO CENTRAL WI. DAY 1 WPC SNOW PROBS FOR >2" ARE 40-70%  
THROUGH THIS ZONE WHICH IS A NOTABLE BUMP UP FROM PREVIOUS  
FORECASTS. WFOS ALONG THIS STRIPE HAVE ISSUED WINTER WEATHER  
ADVISORIES FOR THIS DYNAMIC SNOW BANDING.  
 
   
..CALIFORNIA THROUGH THE SOUTHERN ROCKIES
 
 
DAYS 1-3...  
 
A POTENT LOW PRESSURE SYSTEM CURRENTLY APPROACHING THE SAN  
FRANCISCO BAY AREA WILL CONTINUE SHIFTING DOWN THE CA COAST TONIGHT  
BEFORE STALLING OFF THE SOCAL COAST THROUGH TUESDAY NIGHT. THIS LOW  
DRIFTS INLAND WEDNESDAY AHEAD OF THE NEXT TROUGH THAT APPROACHES  
NORTHERN CA WEDNESDAY NIGHT.  
 
BROAD SOUTHERLY FLOW WRAPPING AROUND THIS LOW WILL PUMP SUBTROPICAL  
PACIFIC MOISTURE NORTHWARD AND SHIFT THE FOCUS OF HEAVY SNOWFALL  
EAST OF THE CREST OF THE SOUTHERN SIERRA NEVADA AND OVER THE WHITE  
MTNS. SNOW LEVELS DROP TO AROUND 7000FT UNDER MODEST HEIGHT FALLS  
WITH MODERATE RATES CONTINUING THROUGH TUESDAY. DAY 1 SNOW PROBS  
FOR >12" ARE 50-90% FOR THE WHITE MTNS AND 40-70% FOR THE HIGHER EASTERN  
SLOPES OF THE SIERRA NEVADA WEST OF OWENS VALLEY.  
 
THE MOISTURE PLUME EXPANDS EAST TUESDAY, SPREADING HIGH LEVEL SNOW  
THROUGH MT CHARLESTON ABOVE LAS VEGAS AND SOUTHERN UTAH RANGES.  
DAY 1.5 SNOW PROBS FOR >8" ARE 50-80% ABOVE THE SNOW LEVELS  
WHICH LINGER AROUND 8000FT INTO WEDNESDAY BEFORE RATES TAPER OFF.  
 
THE SLOW PROGRESSION EAST OF THE MOISTURE PLUME CONTINUES  
WEDNESDAY NIGHT WHEN THE MOGOLLON RIM, WHITE MTNS OF AZ GET HEAVY  
SNOW AS SNOW LEVELS DROP TO AROUND 7000FT AS DO THE SAN JUANS OF CO  
WHERE SNOW LEVELS DROP TO AROUND 8000FT. DAY 3 SNOW PROBS FOR >8"  
ARE 40-80% IN THIS TERRAIN.  
 
   
..NORTHEAST/GREAT LAKES
 
 
DAY 1...  
 
WEST-NORTHWESTERLY FLOW LINGERS OVER THE EASTERN GREAT LAKES AND  
DRIVES CONTINUED LES BANDING INTO TUESDAY. THIS WILL CONTINUE TO BE  
SOUTHEAST OF LAKE ERIE (WHERE THERE IS ALSO LAKE HURON FETCH) FROM  
THE CHAUTAUQUA RIDGE INTO NORTH-CENTRAL PA AND GENERALLY JUST SOUTH  
OF SYRACUSE WHERE A WINTER WEATHER ADVISORY LINGERS TO MID-TUESDAY  
MORNING. DAY 1 SNOW PROBS FOR >4" ARE LIMITED TO AROUND/SOUTH OF  
SYRACUSE, THOUGH THE LOW RESOLUTION ENSEMBLE MEMBER HEAVY PWPF  
OFTEN UNDER DOES THE RISK FOR LES BANDING.  
 
JACKSON  
 

 
 
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