424
FXUS21 KWNC 081752
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 08 2026
SYNOPSIS: MID-LEVEL LOW PRESSURE IS LIKELY TO PROMOTE CHILLY NORTHEASTERLY
FLOW, SUPPORTING AN INCREASED RISK OF MUCH BELOW TEMPERATURES AND FIRST FALL
FREEZES OVER THE NORTHEASTERN CONTIGUOUS U.S. (CONUS). SURFACE LOW DEVELOPMENT
OVER THE UPPER MIDWEST AND AN ACCOMPANYING FRONTAL BOUNDARY EXTENDING SOUTHWARD
INCREASES THE RISK OF HEAVY PRECIPITATION ACROSS THE SOUTHERN PLAINS AND LOWER
MISSISSIPPI VALLEY. FAVORED LOW PRESSURE AT THE SURFACE AND MID-LEVELS OVER
ALASKA SUPPORTS AN INCREASED RISK OF HIGH WINDS AND HEAVY PRECIPITATION EARLY
IN THE PERIOD EARLY IN WEEK-2.
HAZARDS
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF THE NORTHEAST, FRI,
OCT 16.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE SOUTHERN PLAINS, AND LOWER
MISSISSIPPI VALLEY, FRI-SAT, OCT 16-17.
SLIGHT RISK OF HIGH WINDS ACROSS THE ALEUTIANS, ALASKA PENINSULA, AND COASTAL
PORTIONS OF SOUTHWESTERN, SOUTH-CENTRAL, AND SOUTHEASTERN ALASKA, FRI-SAT, OCT
16-17.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF SOUTH-CENTRAL AND SOUTHEASTERN
ALASKA, FRI-SAT, OCT 16-17.
DETAILED SUMMARY
FOR SUNDAY OCTOBER 11 - THURSDAY OCTOBER 15:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY OCTOBER 16 - THURSDAY OCTOBER 22: LATE IN WEEK-1, ENSEMBLE MEAN
SOLUTIONS FROM THE ECENS AND THE GEFS HAVE COME INTO BETTER AGREEMENT IN
REGARDS TO THE STRENGTH AND SHAPE OF A 500-HPA TROUGH LIFTING OUT OVER THE
NORTHEASTERN CONUS. BY THE START OF WEEK-2, ANOTHER 500-HPA TROUGH REMAINS
FAVORED UPSTREAM IN THE LEE OF THE ROCKIES, WHERE MODELS ARE UNANIMOUS IN
FEATURING A DEVELOPING MEAN SURFACE LOW TRAVERSING THE UPPER MIDWEST, WITH AN
ELONGATED MEAN FRONTAL BOUNDARY EXTENDING WELL INTO THE SOUTHERN PLAINS AND
MISSISSIPPI VALLEY LATE NEXT WEEK. AS THE SHORTWAVE DISTURBANCE PROPAGATES
EASTWARD INTO THE FOLLOWING WEEKEND, RESIDUAL CYCLONIC FLOW IS EXPECTED TO
REMAIN ESTABLISHED ACROSS SOUTHWESTERN CONUS UNDERNEATH AN AMPLIFIED RIDGE
CENTER TO THE NORTH. THE PLACEMENT AND TIMING OF THESE MID-LEVEL FEATURES LOOKS
TO CONTRIBUTE TO A FAVORABLE ENVIRONMENT FOR ENHANCED AND POSSIBLY HEAVY
PRECIPITATION ALONG THE MEAN FRONTAL BOUNDARY, BEFORE AN ANOMALOUSLY COOLER AND
DRIER AIR MASS DESCENDS FROM THE CANADIAN PRAIRIES AND OVERSPREADS MUCH OF THE
CONUS EAST OF THE ROCKIES LATER IN WEEK-2. MEANWHILE OVER ALASKA, AMPLIFIED
MID-LEVEL TROUGHING REMAINS FAVORED OVER THE BERING STRAIT AND THE WESTERN
MAINLAND LATE IN WEEK-1, WHERE BETTER AGREEMENT EXISTS BETWEEN THE GEFS AND
ECENS FAVORING MORE ZONAL FLOW BY THE MIDDLE OF THE PERIOD TO QUELL ANY WIND
AND PRECIPITATION RELATED HAZARDS.
WHILE TEMPERATURES ARE EXPECTED TO MODERATE WITH 500-HPA TROUGHING FAVORED TO
LIFT OUT OVER THE CANADIAN MARITIMES AND NORTHEAST LATER NEXT WEEK, A SLIGHT
RISK OF MUCH BELOW NORMAL TEMPERATURES REMAINS POSTED FOR OCT 16 BASED ON BOTH
RAW AND CALIBRATED TEMPERATURES TOOLS DEPICTING INCREASED CHANCES FOR MINIMUM
TEMPERATURES FALLING BELOW THE 15TH PERCENTILE AND BELOW FREEZING.
CLIMATOLOGICALLY, FIRST FALL FREEZES GENERALLY OCCUR BETWEEN LATE SEPTEMBER
THROUGH MID-OCTOBER FOR THIS PART OF THE COUNTRY, THOUGH ANY TEMPERATURES
DIPPING TO NEAR FREEZING LEVELS MAY STILL TRIGGER COLD TEMPERATURE ADVISORIES
FOR AREAS THAT HAVE NOT EXPERIENCED THEIR FIRST FROST AND/OR FREEZES EARLY IN
THE PERIOD. TIED TO THE TROUGHING UPSTREAM OVER THE UPPER MIDWEST, BOTH THE
GEFS AND ECENS FAVOR A STRONGER MEAN SURFACE HIGH BEHIND THE MEAN FRONTAL
BOUNDARY COMPARED TO YESTERDAY. A CORRESPONDING UPTICK IN COLD SIGNALS IS ALSO
EVIDENT IN THE PROBABILISTIC EXTREMES TOOLS (PETS), WHICH DEPICT A LARGER
COVERAGE OF AT LEAST 20% CHANCES FOR MINIMUM TEMPERATURES FALLING BELOW THE
15TH PERCENTILE ALONG THE FRONTAL BOUNDARY FROM THE SOUTHERN PLAINS TO THE
GREAT LAKES EARLY IN THE PERIOD. WITH THE COLDEST TEMPERATURES LIKELY FURTHER
NORTH ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST, ANY RISK OF SUBFREEZING
TEMPERATURES ARE EXPECTED TO BE TRANSIENT, AS MID-LEVEL HEIGHTS BEGIN TO
RAPIDLY RISE ACROSS THE PART OF THE COUNTY. AS A RESULT, NO CORRESPONDING
TEMPERATURE HAZARDS ARE POSTED.
WITH ENHANCED ATMOSPHERIC MOISTURE FAVORED AHEAD OF THE MEAN FRONTAL BOUNDARY,
A SLIGHT RISK OF HEAVY PRECIPITATION REMAINS POSTED BASED ON CONTINUED SUPPORT
IN THE PRECIPITATION GUIDANCE. A DRIER MEAN SOLUTION IS SEEN IN THE GEFS EARLY
IN THE PERIOD COMPARED TO YESTERDAY, WHICH IS NOTABLE AND SOMEWHAT SURPRISING
CONSIDERING THE STRONGER FRONTAL FORCING BEING FAVORED. HOWEVER, THERE IS
BETTER SUPPORT IN THE CANADIAN THAT WELL ALIGNS WITH THE ECMWF AND FOCUSES THIS
HEAVY PRECIPITATION OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. AS
A RESULT, THE SLIGHT RISK COVERAGE IS ADJUSTED TO EXCLUDE PORTIONS OF THE
MIDDLE MISSISSIPPI, OHIO AND TENNESSEE VALLEYS, AND REMAINS VALID THROUGH OCT
17 BEFORE DRIER AIR OVERSPREADS THE HIGHLIGHTED AREA. DUE TO DRIER CONDITIONS
EXPECTED FURTHER EAST, THE FLOOD POSSIBLE HAZARD IS REMOVED OVER THE EASTERN
AND CENTRAL PORTIONS OF THE GULF COAST REGION. HOWEVER, LOCALIZED FLOODING
CANNOT BE RULED OUT AS ANY ADDITIONAL RAINFALL COULD WORSEN SATURATED GROUND
CONDITIONS EXPECTED IN THE WAKE OF HURRICANE ISAIAS THAT IS LIKELY TO IMPACT
THE REGION BASED ON THE LATEST NATIONAL HURRICANE CENTER OFFICIAL TRACK
FORECASTS DURING WEEK-1.
AMPLIFIED 500-HPA TROUGHING IS FAVORED OVER THE BERING SEA LATE IN WEEK-1.
ALTHOUGH THIS MID-LEVEL FEATURE IS EXPECTED TO DEAMPLIFY, THERE CONTINUES TO BE
TOOL SUPPORT FOR AN INCREASED RISK OF EPISODES OF HIGH WINDS AND HEAVY
PRECIPITATION ASSOCIATED WITH MEAN SURFACE LOW SITUATED IN THE GULF OF ALASKA.
HOWEVER, DUE TO MORE ZONAL MID-LEVEL FLOW EXPECTED WITH DIMINISHED SIGNALS IN
BOTH THE WIND AND PRECIPITATION BASED PETS COMPARED TO YESTERDAY, ONLY SLIGHT
RISKS OF HEAVY PRECIPITATION AND HIGH WINDS ARE ISSUED FOR EARLY WEEK-2, AND
THE MODERATE RISK OF HIGH WINDS IS DISCONTINUED IN THE UPDATED OUTLOOK.
FORECASTER: NICK NOVELLA
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