976
FOUS11 KWBC 160835
QPFHSD
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
335 AM EST TUE DEC 16 2025
VALID 12Z TUE DEC 16 2025 - 12Z FRI DEC 19 2025
..CASCADES AND NORTHERN ROCKIES
DAYS 1-3...
SNOW LEVELS ON THE WA CASCADES RISE FROM 4000FT TO 5500FT THROUGH
THIS EVENING UNDER BRIEF RIDGING UNTIL A SHARP SHORTWAVE TROUGH
AXIS PUSHES ACROSS THE CASCADES BY 12Z WEDNESDAY ON THE HEAD OF A
170FT WNWLY JET. THIS POTENT COLD FRONT BRINGS A SHARP DROP IN
SNOW LEVELS TONIGHT, REACHING 2000FT IN WA AND 4000FT IN OR EARLY
WEDNESDAY. THE PRECIP RATES RAPIDLY DROP WITH THE SNOW LEVELS, BUT
THERE SHOULD BE IMPACTFUL SNOW AT PASS LEVELS INCLUDING
SNOQUALMIE. LOW SNOW LEVELS AND MODERATE PRECIP RATES PERSIST INTO
THURSDAY BEFORE AN INTENSE PUSH OF MOISTURE AND HEIGHT RISES MOVE
IN, PARTICULARLY INTO OREGON. THE LATEST WPC PROBABILITIES REMAIN
HIGH FOR SNOWFALL ACCUMULATIONS >8" (PARTICULARLY FOR THE
WASHINGTON CASCADES) EACH OF DAYS 1-3, WITH 72-HOUR PROBABILITIES
THROUGH THURSDAY REMAINING HIGH FOR ACCUMULATIONS >24".
MOISTURE AND WINDY CONDITIONS WILL PROGRESS EASTWARD OVER THE
NORTHERN ROCKIES TODAY, FOLLOWED MORE SURGES TONIGHT AND THURSDAY,
WITH FALLING SNOW LEVELS. THE LATEST WPC PROBABILITIES FOR
SNOWFALL >8" ARE MODERATE TO HIGH (40-80%) FOR THE HIGHEST
ELEVATIONS OF CENTRAL AND NORTHERN ID AND WESTERN MT DAY 1,
EXPANDING SOUTH THROUGH WESTERN WYOMING WITH 40-80% PROBS ON DAY
2, AND THEN AN INCREASE OVER SIMILAR AREAS OF MD/ID/WY ON DAY 3
WITH TO 50-90%.
..NORTHERN PLAINS, UPPER MIDWEST, GREAT LAKES
DAY 3...
STRONG LOW PRESSURE TRACKS EASTWARD ALONG THE U.S./CANADA BORDER
ROUGHLY FROM MONTANA TO LAKE SUPERIOR WEDNESDAY THROUGH THURSDAY. A
WINTRY MIX IS POSSIBLE IN THE WARM AIR ADVECTION AHEAD OF THE
SYSTEM OVER THE UPPER MIDWEST WEDNESDAY NIGHT, BUT THE MAIN CONCERN
IS THE LEADING AXIS OF HEAVY SNOW ON THE COLD CONVEYOR BELT THAT
CONNECTS TO A WRAP AROUND DEFORMATION BAND WITH AN INTENSE PRESSURE
GRADIENT AND HIGH WIND/BLIZZARD THREAT. FAIRLY FAST FORWARD MOTION
AND THE LIKELIHOOD THAT MOST OF THE LEADING BANDS SHOULD BE NORTH
OF THE BORDER LIMITS THE OVERALL SNOWFALL FOR THE U.S. THAT SAID,
DAY 2.5 WPC PROBABILITIES FOR SNOWFALL >4" REMAIN MODERATE
(40-70%) FROM NORTHEAST ND THROUGH FAR NORTHERN MINNESOTA, WITH
10-30% FOR >8" IN THE NORTHERN ARROWHEAD. IN GENERAL, THE WIND
FIELD SHOULD BE WORST SOUTH OF THE NEW SNOW, BUT OVER THE DAKOTAS
AND MINNESOTA WHICH HAS A DECENT SNOWPACK THAT COULD BE DRIVEN INTO
GROUND BLIZZARD CONDITIONS. PLEASE STAY TUNED ON THIS WIND-WHIPPED
FORECAST.
THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.
JACKSON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page