836
FXUS01 KWBC 090801
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EST TUE DEC 09 2025
VALID 12Z TUE DEC 09 2025 - 12Z THU DEC 11 2025
...ATMOSPHERIC RIVER TO USHER IN SEVERAL DAYS OF HEAVY RAIN INTO
THE PACIFIC NORTHWEST AND SNOW INTO THE NORTHERN ROCKIES...
...A CLIPPER WILL BRING A PERIOD OF SNOW ACROSS THE UPPER MIDWEST
AND THE GREAT LAKES THROUGH TUESDAY...
...A STRONGER CLIPPER IS EXPECTED TO BRING THE THREAT OF HEAVY
SNOW AND HIGH WINDS ACROSS THE UPPER MIDWEST ON TUESDAY THEN
ACROSS THE GREAT LAKES ON WEDNESDAY...
A WEATHER PATTERN THAT SUPPORTS HEAVY RAIN ACROSS COASTAL PACIFIC
NORTHWEST WILL TRANSITION TO COLD AND SNOWY WEATHER FOR THE
NORTHERN TIER STATES. THIS WILL BE IN STARK CONTRAST WITH DRY AND
MILDER THAN NORMAL CONDITIONS ACROSS THE SOUTHWEST. IN THE
SHORT-TERM, ARCTIC AIR IN THE WAKE OF AN OFFSHORE LOW PRESSURE
CENTER WILL CAUSE TEMPERATURES TO CRASH INTO THE TEENS THIS
MORNING AS FAR SOUTH AS NORTH CAROLINA, WHICH WILL CHALLENGE SOME
LOW TEMPERATURE RECORDS ACROSS THE INTERIOR MID-ATLANTIC TO
SOUTHERN NEW ENGLAND.
MEANWHILE, A PROLONGED ATMOSPHERIC RIVER EVENT CONTINUES OVER THE
PACIFIC NORTHWEST, WITH RADAR AND SURFACE OBSERVATIONS
HIGHLIGHTING STEADY HEAVY RAINFALL IN THE REGION. THE ARRIVAL OF
WIDESPREAD HEAVY RAIN TODAY SIGNALS THE BEGINNING OF SEVERAL DAYS
OF HEAVY RAINFALL EXPECTED TO IMPACT WESTERN WASHINGTON AND
NORTHWESTERN OREGON. THE POTENT TRANS-PACIFIC JET STREAM WILL
CONTINUE TO TRANSPORT SUB-TROPICAL MOISTURE FROM THE PACIFIC AND
DUMP THE MOISTURE AS HEAVY RAIN CLOSER TO THE COAST, AND MORE THAN
A FOOT OF NEW SNOW FOR THE NORTHERN ROCKIES IN NORTHWESTERN
WYOMING. ISOLATED TO SCATTERED INSTANCES OF FLASH FLOODING ARE
POSSIBLE NEAR THE COAST AND INTO THE CASCADES THROUGH MIDWEEK,
WHERE A SLEW OF FLOOD WATCHES ARE IN EFFECT. RAINFALL ASIDE, PARTS
OF THE PACIFIC NORTHWEST, NORTHERN ROCKIES, AND NORTHERN PLAINS
CAN ALSO EXPECT VERY GUSTY WINDS THROUGH THE NEXT COUPLE OF DAYS
AS THE SAME PACIFIC JET DEVELOPS A STRONG CLIPPER SYSTEM IN THE
CANADIAN ROCKIES. AS THIS CLIPPER SYSTEM EJECTS EASTWARD INTO THE
NORTHERN PLAINS AND UPPER MIDWEST LATE TODAY, A SWATH OF MODERATE
TO LOCALLY HEAVY SNOW IS EXPECTED DEVELOP ALONG THE NORTHERN FLANK
OF THE LOW CENTER. SNOWFALL AMOUNTS OF 4 TO 8 INCHES CAN STILL BE
EXPECTED FROM NORTHEASTERN CORNER OF NORTH DAKOTA THROUGH THE
CENTRAL GREAT LAKES. THIS CLIPPER SYSTEM IS FORECAST TO QUICKLY
INTENSIFY, PRODUCING AN EXPANDING AREA OF VERY STRONG AND GUSTY
WINDS TO ACCOMPANY THE SNOW. BY TOMORROW MORNING, THE MATURING
CLIPPER MIGRATES INTO THE LOWER GREAT LAKES, SPREADING WINTRY
WEATHER TOWARDS THE INTERIOR NORTHEAST. THE SNOW WILL BE TAPERING
OFF ACROSS THE NORTHERN PLAINS ON WEDNESDAY BEHIND THE STORM BUT
SNOW WILL BE EXPANDING THROUGH THE LOWER GREAT LAKES AND INTO
INTERIOR NORTHWEST AS THE STORM CENTER APPROACHES. RAIN WILL BE
FALLING FARTHER SOUTH ACROSS THE OHIO VALLEY ON WEDNESDAY, MOVING
INTO THE NORTHERN MID-ATLANTIC LATER THAT DAY.
MEANWHILE, THE CENTRAL AND SOUTHERN PLAINS AS WELL AS THE DEEP
SOUTH WILL ENJOY FINE AND DRY WEATHER WITH A WARMING TREND
ESPECIALLY FOR THE PLAINS. THE SOUTHWEST WILL REMAIN DRY AND
MILDER THAN NORMAL WHILE MUCH MILDER THAN NORMAL CONDITIONS ARE
FORECAST FOR THE NORTHWEST INTO THE NORTHERN HIGH PLAINS ALONG
WITH THE INCLEMENT WEATHER. A GRADUAL DRYING TREND IS FORECAST FOR
THE SUNSHINE STATE AS A COLD FRONT PULLS OUT TO SEA.
ASHERMAN/KONG
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