006  
FOUS11 KWBC 191858  
QPFHSD  
 
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
158 PM EST WED NOV 19 2025  
 
VALID 00Z THU NOV 20 2025 - 00Z SUN NOV 23 2025  
   
..SOUTHERN & CENTRAL ROCKIES  
 
DAYS 1-2...  
 
AN UPPER LOW TRACKING THROUGH THE DESERT SOUTHWEST TODAY WILL  
SHARPEN UP AND TAKE ON AN INCREASINGLY NEGATIVE TILT OVER NORTHERN  
MEXICO TONIGHT AND INTO THURSDAY MORNING. HEALTHY 500MB PVA AND AN  
INFLUX OF MOISTURE (COURTESY OF IVT VALUES TOPPING 400 KG/M/S THAT  
EXCEED THE 97.5 CLIMATOLOGICAL PERCENTILE PER ECMWF SATS) WILL  
BE THE KEY INGREDIENTS IN A BLOSSOMING AREA OF PRECIPITATION OVER  
AZ, NM, SOUTHERN UT, AND SOUTHERN CO. TEMPERATURES ALOFT ARE NOT  
OVERLY COLD AND THE ANTECEDENT AIR-MASS IS GENERALLY MILD, THUS  
FORCING MOST OF THE IMPENDING SNOWFALL TO OCCUR IN THE MORE  
REMOTE/HIGHER TERRAIN OF THE SOUTHERN ROCKIES.  
 
AS THE UPPER TROUGH REACHES THE SOUTHERN PLAINS THURSDAY NIGHT,  
THE 500MB TROUGH WILL BECOME INVERTED WITH A NARROW TONGUE OF  
EASTERLY UPSLOPE FLOW STILL PRODUCING A PERSISTENT LIGHT-TO-  
MODERATE SNOW IN THE FORECAST INTO FRIDAY MORNING. SNOW LEVELS FOR  
THE EVENT MAY DIP AS LOW AS 6,000FT IN PARTS OF THE WASATCH AND AS  
FAR SOUTH AND WEST AS ZION NAT'L PARK, BUT THE BULK OF THE MORE  
IMPACTFUL SNOWFALL TOTALS WILL RESIDE ABOVE 7,000FT IN THE  
MOUNTAINS SURROUNDING LAS VEGAS AND THE SOUTHERN WASATCH, ABOVE  
8,000FT IN THE MOGOLLON RIM AND GILA MOUNTAINS OF AZ, ABOVE  
9,000FT IN THE SAN JUANS AND SANGRE DE CRISTO, AND ABOVE 10,000FT  
ALONG THE CO FRONT RANGE. WPC PROBABILITIES SHOW MOST OF THESE  
RANGES ABOVE THE LISTED ELEVATIONS ARE LIKELY TO SEE AT LEAST 4"  
OF SNOWFALL, BUT IT WILL BE IN THESE MOUNTAINS' MORE  
REMOTE/ELEVATED REACHES THAT SPORT LOW-TO-MODERATE CHANCES  
(30-50%) FOR SNOWFALL TOTALS >8" THROUGH FRIDAY.  
   
..CALIFORNIA  
 
DAYS 1-3...  
 
AS THIS LEAD UPPER-TROUGH TRACKS TOWARDS THE SOUTH-CENTRAL U.S. ON  
THURSDAY, THE NEXT PACIFIC UPPER-LEVEL TROUGH IS HOT ON ITS HEELS  
AS IT DIVES SOUTHWARD ALONG THE CA COAST. A PROGRESSIVE SYSTEM, IT  
WILL PRODUCE A SWATH OF ACCUMULATING SNOWFALL AT/ABOVE 5,000FT  
FROM THE TRINITY/SISKIYOU MOUNTAINS OF NORTHERN CA ON SOUTH ALONG  
THE SIERRA NEVADA AND EVEN THE PEAKS OF THE TRANSVERSE AND  
PENINSULAR RANGES. THE HEAVIEST SNOWFALL FOR THE SIERRA NEVADA IS  
EXPECTED ON THURSDAY WITH SNOWFALL TAPERING OFF BY FRIDAY MORNING.  
WPC PROBABILITIES DEPICT MODERATE-TO-HIGH CHANCES PROBABILITIES  
(50-8%) FOR SNOWFALL TOTALS >6" IN THE CENTRAL AND SOUTHERN SIERRA  
NEVADA WITH LOCALIZED TOTALS APPROACHING 12" IN THE >10,000FT  
PEAKS.  
 
SNOW WILL PICK UP IN INTENSITY OVER THE PEAKS OF THE SAN GABRIEL  
AND SAN BERNADINO MOUNTAINS STARTING THURSDAY AFTERNOON AND LASTING  
THROUGH FRIDAY MORNING. SNOW SHOULD TAPER OFF IN THE PEAKS OF THE  
TRANSVERSE AND PENINSULAR RANGES BY SATURDAY MORNING. SNOW LEVELS  
ARE LIKELY TO BE AS LOW AS 6,000FT WITH MINOR ACCUMULATIONS  
POSSIBLE AROUND THAT ELEVATION, BUT THE HEAVIEST SNOWFALL IS LIKELY  
TO OCCUR ABOVE 7,000FT WHERE WPC PROBABILITIES SHOW MODERATE-TO-  
HIGH CHANCES (50-80%) FOR SNOWFALL TOTALS >6" AND EVEN LOW-TO-  
MODERATE CHANCES (30-50%) FOR LOCALIZED AMOUNTS >12" IN THE PEAKS  
OF THE SAN BERNADINO MOUNTAINS.  
 
THE PROBABILITY OF SIGNIFICANT ICE ACROSS THE CONUS IS LESS THAN  
10 PERCENT.  
 
MULLINAX  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page