969
FXUS21 KWNC 031940
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST NOVEMBER 03 2025
SYNOPSIS: MID-LEVEL LOW PRESSURE FORECAST OVER THE NORTHEASTERN PACIFIC FAVORS
AN INCREASED RISK OF HEAVY PRECIPITATION, HIGH ELEVATION SNOWFALL, AND HIGH
WINDS OVER PORTIONS OF THE WESTERN CONTIGUOUS U.S. (CONUS) DURING WEEK-2. AN
EARLY TASTE OF WINTER IS PREDICTED ACROSS THE EAST AROUND THE START OF THE
PERIOD AS A DEPARTING MID-LEVEL LOW BRINGS IN SOME OF THE COLDEST AIR OF THE
SEASON THUS FAR, WITH A LIKELY END OF THE GROWING SEASON ACROSS THE
MID-ATLANTIC COASTAL PLAIN. HAZARDOUS TEMPERATURES COULD EXTEND INTO PARTS OF
THE SOUTHEAST. LAKE EFFECT SNOW IS POSSIBLE DOWNWIND OF LAKES ERIE AND ONTARIO.
HAZARDS
MODERATE RISK OF MUCH BELOW NORMAL TEMPERATURES ACROSS MUCH OF THE MID-ATLANTIC
COASTAL PLAIN INTO THE SOUTHEAST, TUE, NOV 11.
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE OHIO AND
TENNESSEE VALLEYS, NORTHEAST, MID-ATLANTIC, APPALACHIANS, AND SOUTHEAST,
TUE-WED, NOV 11-12.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA, TUE-MON, NOV 11-17.
SLIGHT RISK OF HEAVY SNOW ACROSS PORTIONS OF THE CASCADES, SIERRA NEVADA, AND
KLAMATH MOUNTAINS, TUE-MON, NOV 11-17.
SLIGHT RISK OF HEAVY SNOW ACROSS PORTIONS OF THE NORTHERN ROCKIES, TUE-MON, NOV
11-17.
SLIGHT RISK OF HEAVY SNOW ACROSS PORTIONS OF THE INTERIOR NORTHEAST AND INTO
THE ALLEGHENY FRONT, TUE-THU, NOV 11-13.
SLIGHT RISK OF HIGH WINDS ACROSS ALONG THE WEST COAST OF THE CONUS, TUE-MON,
NOV 11-17.
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE NORTHERN MID-ATLANTIC AND
NORTHEAST, TUE-THU, NOV 11-13.
DETAILED SUMMARY
FOR THURSDAY NOVEMBER 06 - MONDAY NOVEMBER 10:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY NOVEMBER 11 - MONDAY NOVEMBER 17: A PROGRESSIVE MID-LEVEL PATTERN
IS FORECAST ACROSS NORTH AMERICA DURING WEEK-2, WITH THE 0Z ECENS, GEFS, AND
CMCE MODELS DEPICTING SEVERAL SHORTWAVE TROUGHS TRAVERSING THE FORECAST DOMAIN.
INTERMITTENT PERIODS OF UNSETTLED WEATHER ARE LIKELY TO CONTINUE ACROSS THE
WEST TIED TO EACH TROUGH PASSAGE. THE GEFS AND ECENS PROBABILISTIC EXTREMES
TOOLS (PETS) DEPICT AT LEAST A 20 PERCENT CHANCE OF 3-DAY PRECIPITATION TOTALS
EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE AND 1.5-INCHES ACROSS MUCH OF THE
PACIFIC NORTHWEST AND NORTHERN CALIFORNIA THROUGHOUT THE PERIOD. COMPARED TO
YESTERDAY, THERE IS ALSO A GREATER EXTENSION OF ONSHORE FLOW FARTHER SOUTH,
WITH AN ASSOCIATED INCREASE IN PRECIPITATION TOTALS OVER SOUTHERN CALIFORNIA.
THE LOW CLIMATOLOGY IS DRIVING THE PERCENTILE PROBABILITIES HIGHER IN THE PETS,
WITH ACTUAL PRECIPITATION VALUES LOWER RELATIVE TO NORTHERN AREAS. THEREFORE,
THE SLIGHT RISK OF HEAVY PRECIPITATION INCLUDES THE PACIFIC NORTHWEST TO ABOUT
SAN FRANCISCO, CA, AND IS NOW VALID FOR ALL OF WEEK-2. MODELS INDICATE THE
HIGHEST 24-HOUR PRECIPITATION TOTALS ALONG THE WEST COAST ON DAYS 9 AND 10 (NOV
12-13) AS TROUGHING AMPLIFIES OVER THE EASTERN PACIFIC. THIS PERIOD WILL
CONTINUE TO BE MONITORED AND A MODERATE RISK MAY BE CONSIDERED TOMORROW. AN
ACCOMPANYING SLIGHT RISK OF HIGH WINDS IS EXTENDED ALONG THE ENTIRE WEST COAST
FOR ALL OF WEEK-2, CONSISTENT WITH THE ECENS PET DEPICTING AT LEAST A 20
PERCENT CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 25-MPH
CORRESPONDING TO THE PREDICTED SOUTHERLY EXTENSION OF ONSHORE FLOW. SLIGHT
RISKS OF HEAVY SNOW ARE HIGHLIGHTED ACROSS THE CASCADES, KLAMATH, AND SIERRA
NEVADA MOUNTAINS, AS WELL AS THE NORTHERN ROCKIES. SOME OF THE UNCALIBRATED
MODEL GUIDANCE WOULD SUPPORT BRINGING THE SNOW HAZARD INTO PARTS OF THE CENTRAL
ROCKIES. HOWEVER, THE ANOMALOUS RIDGE DOWNSTREAM REDUCES THE CHANCES OF THIS
OCCURRING BUT THIS AREA WILL CONTINUE TO BE MONITORED.
OVER THE PAST FEW DAYS, THERE HAVE BEEN SIGNIFICANT MODEL TRENDS TOWARD THE
DEVELOPMENT OF A NEGATIVE NORTH ATLANTIC OSCILLATION (-NAO) AND ASSOCIATED
AMPLIFIED TROUGHING ACROSS THE NORTHEASTERN U.S. EARLY IN WEEK-2. THIS PATTERN
SUPPORTS A COLDER TEMPERATURE FORECAST ACROSS THE EAST. THE 0Z ECENS IS QUITE
ROBUST WITH THIS FEATURE, WITH ITS CORRESPONDING PET DEPICTING AT LEAST A 40
PERCENT CHANCE OF MINIMUM TEMPERATURES FALLING BELOW THE 15TH CLIMATOLOGICAL
PERCENTILE OVER MANY AREAS ON DAY-8 (NOV 11), WITH THE ELEVATED POTENTIAL FOR A
HARD FREEZE (BELOW 28 DEG F) OVER THE INTERIOR EAST. THE 0Z GEFS, ON THE OTHER
HAND, IS MORE PROGRESSIVE AND INDICATES MORE PACIFIC FLOW AND WEAK RIDGING
DEVELOPING OVER THE SOUTHEAST, LIKELY REDUCING THE EXTENT OF THE COLD. HOWEVER,
THE 6Z, AND TO A GREATER EXTENT, THE 12Z GEFS HAVE BOTH TRENDED TOWARD A MORE
AMPLIFIED TROUGH AND A COLDER SOLUTION. RECENT DETERMINISTIC SOLUTIONS FROM THE
ECMWF AND GFS ALSO LEAN ON THE COLDER SIDE OF THE ENSEMBLE ENVELOPE. GIVEN
THESE TRENDS, A MODERATE RISK FOR MUCH BELOW NORMAL TEMPERATURES IS POSTED
ACROSS MUCH OF THE MID-ATLANTIC COASTAL PLAIN INTO THE SOUTHEAST ON DAY-8 (NOV
11). FOR THE MORE NORTHERN AREAS OF THE REGION, THERE IS INCREASED POTENTIAL
FOR SUBFREEZING OVERNIGHT TEMPERATURES, LIKELY RESULTING IN AN END TO THE
GROWING SEASON ACROSS AREAS THAT HAVE YET TO SEE A FIRST FREEZE. ACROSS THE
SOUTHEAST, TEMPERATURES POSSIBLY FALLING BELOW 40 DEG F MAY RESULT IN FROST
FORMATION AND DAMAGE TO SENSITIVE VEGETATION. A SLIGHT RISK OF MUCH BELOW
NORMAL TEMPERATURES CONTINUES THROUGH NOV 12, WITH A QUICK MODERATION
THEREAFTER. THE SLIGHT RISK EXTENDS FARTHER WEST ACROSS THE OHIO AND TENNESSEE
VALLEYS WHERE COLDER BUT LESS IMPACTFUL TEMPERATURES ARE LIKELY.
A TIGHT PRESSURE GRADIENT BETWEEN SURFACE LOW PRESSURE OVER EASTERN CANADA AND
SURFACE HIGH PRESSURE OVER THE SOUTHEAST FAVORS ENHANCED WINDS ACROSS THE
NORTHEAST, WITH THE ECENS PET SUPPORTING A SLIGHT RISK FOR HIGH WINDS, NOV
11-13, WHERE WIND SPEEDS MAY EXCEED 20-MPH. WHILE NEW ENGLAND HAS ALREADY
EXPERIENCED A FIRST FREEZE PRECLUDING A TEMPERATURE HAZARD, THE INCREASED WIND
SPEEDS WILL LIKELY LEAD TO A NOTABLE DECREASE IN WIND CHILL VALUES. THE
CYCLONIC FLOW PATTERN COMBINED WITH THE ANOMALOUSLY COLD AIR ALSO INCREASES THE
POTENTIAL FOR OCCASIONAL EPISODES OF SNOW ACROSS THE INTERIOR NORTHEAST AND
EXTENDING ALONG THE ALLEGHENY FRONT, WITH LAKE EFFECT SNOW ALSO POSSIBLE
DOWNWIND OF LAKES ONTARIO AND ERIE. THEREFORE, A SLIGHT RISK FOR HEAVY SNOW IS
POSTED ACROSS THESE AREAS, NOV 11-13. SNOWFALL AMOUNTS IN THE MODELS ARE NOT
ALL THAT IMPRESSIVE, BUT THIS WOULD BE NOTEWORTHY GIVEN THAT IT IS EARLY IN THE
SEASON.
ACROSS ALASKA, RELATIVELY DRIER CONDITIONS ARE FORECAST ACROSS SOUTHEAST ALASKA
AS THE STRONGEST ONSHORE FLOW SHIFTS SOUTHWARD TO THE WESTERN CONUS. THE
MID-LEVEL PATTERN IS MORE VARIABLE THROUGHOUT WEEK-2, ALTHOUGH MORE TROUGHING
IS NOTED ACROSS THE BERING SEA TOWARD THE END OF THE PERIOD. FOR THE PERIOD AS
A WHOLE, NEAR- TO ABOVE-NORMAL TEMPERATURES AND PRECIPITATION ARE FORECAST WITH
NO HAZARDS POSTED ACROSS THE STATE.
FORECASTER: THOMAS COLLOW
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