468
FXUS21 KWNC 231808
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 23 2025
SYNOPSIS: PRIOR TO THE START OF WEEK-2, SURFACE LOW DEVELOPMENT IS FORECAST
OFFSHORE OF THE MID-ATLANTIC. THIS LOW PRESSURE SYSTEM IS THEN EXPECTED TO
TRACK NORTHWARD TO NEAR EASTERN NEW ENGLAND BY HALLOWEEN. THE FUTURE TRACK OF
TROPICAL STORM MELISSA, CURRENTLY LOCATED SOUTH OF JAMAICA, AND ITS
INTERACTION, IF ANY, WITH THIS COASTAL LOW REMAINS HIGHLY UNCERTAIN. FOLLOWING
THIS WEEK'S HEAVY PRECIPITATION FORECAST FOR THE PACIFIC NORTHWEST, ADDITIONAL
HEAVY PRECIPITATION IS LIKELY TO RETURN TO NORTHWESTERN OREGON AND WESTERN
WASHINGTON ON HALLOWEEN. SOUTHEASTERN ALASKA ALSO HAS AN ELEVATED RISK OF
HAZARDOUS PRECIPITATION AND WINDS DUE TO MID-LEVEL LOW PRESSURE FORECAST OVER
THE GULF OF ALASKA.
HAZARDS
MODERATE RISK OF HEAVY PRECIPITATION ACROSS EASTERN NEW ENGLAND, FRI, OCT 31.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE NORTHEAST, FRI-SAT, OCT
31-NOV 1.
SLIGHT RISK OF HIGH WINDS FOR THE NORTHEAST, MID-ATLANTIC, CENTRAL
APPALACHIANS, AND EASTERN GREAT LAKES, FRI-SAT, OCT 31-NOV 1.
MODERATE RISK OF HEAVY PRECIPITATION ACROSS PORTIONS OF THE PACIFIC NORTHWEST,
FRI-SAT, OCT 31-NOV 1.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS NORTHERN CALIFORNIA AND THE PACIFIC
NORTHWEST, FRI-MON, OCT 31-NOV 3.
MODERATE RISK OF HEAVY SNOW ACROSS THE NORTHERN CASCADES, FRI-SAT, OCT 31-NOV 1.
SLIGHT RISK OF HEAVY SNOW ACROSS THE NORTHERN CASCADES AND NORTHERN ROCKIES,
FRI-MON, OCT 31-NOV 3.
MODERATE RISK OF HIGH WINDS ACROSS PORTIONS OF THE PACIFIC NORTHWEST, FRI-SAT,
OCT 31-NOV 1.
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE PACIFIC NORTHWEST, FRI-MON,
OCT 31-NOV 3.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR PARTS OF THE SOUTHEAST,
FRI-SAT, OCT 31-NOV 1.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS SOUTHEAST ALASKA, FRI-THU, OCT 31-NOV
6.
SLIGHT RISK OF HEAVY SNOW ACROSS HIGH ELEVATIONS OF SOUTHEAST ALASKA, THE
ALASKA RANGE, KENAI MOUNTAINS, AND THE WRANGELL MOUNTAINS, FRI-THU, OCT 31-NOV
6.
SLIGHT RISK OF HIGH WINDS ACROSS COASTAL SOUTHEASTERN ALASKA, FRI-SAT, OCT
31-NOV 1.
DETAILED SUMMARY
FOR SUNDAY OCTOBER 26 - THURSDAY OCTOBER 30:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY OCTOBER 31 - THURSDAY NOVEMBER 06: THE ECENS, GEFS, AND CMCE REMAIN
CONSISTENT AND IN GOOD AGREEMENT THAT A 500-HPA TROUGH AMPLIFIES OVER THE EAST
DURING THE MIDDLE PART OF NEXT WEEK. THIS AMPLIFYING MID-LEVEL TROUGH IS LIKELY
TO SPAWN A STRENGTHENING LOW PRESSURE SYSTEM OFFSHORE OF THE DELMARVA PRIOR TO
THE START OF WEEK-2. ON HALLOWEEN, THE ENSEMBLE MEAN CONSENSUS FROM THE ECENS
AND GEFS FAVORS A NORTHEASTWARD TRACK NEAR OR OFFSHORE OF THE NORTHEAST. IT IS
NOTABLE THAT THE ECENS HAS TRENDED AWAY FROM ITS CLOSED 500-HPA LOW OVER THE
EASTERN GREAT LAKES FROM TWO DAYS AGO AND NOW HAS A MORE PROGRESSIVE MID-LEVEL
TROUGH. THIS MODEL TREND WOULD MAKE AN OFFSHORE TRACK MORE LIKELY. REGARDLESS
OF THE EXACT TRACK, THERE IS AN ELEVATED RISK OF HEAVY PRECIPITATION, HIGH
WINDS, AND COASTAL FLOODING FROM THE NEW JERSEY NORTHWARD ON OCTOBER 31ST.
BASED ON CONTINUITY FROM PREVIOUS OUTLOOKS AND 24-HOUR PRECIPITATION AMOUNTS
FROM THE ECENS AND GEFS, A MODERATE RISK OF HEAVY PRECIPITATION IS POSTED FOR
PARTS OF EASTERN NEW ENGLAND ON OCTOBER 31. A SLIGHT RISK OF HEAVY
PRECIPITATION EXTENDS SOUTH TO NEW JERSEY AND IS VALID THROUGH NOVEMBER 1ST IN
DEFERENCE TO THE SLOWER MOVING ENSEMBLE MEMBERS. HEAVY PRECIPITATION MAY
TRIGGER SMALL STREAM AND URBAN FLOODING ACROSS THE NORTHEAST. A SLIGHT RISK OF
HIGH WINDS IS ALSO ASSOCIATED WITH THE COASTAL LOW AND COVERS INLAND AREAS OF
THE NORTHEAST (VALID OCT 31-NOV 1). HOWEVER, LARGE ENSEMBLE SPREAD ON THE
INTENSITY OF THE SURFACE LOW PRECLUDES A MODERATE RISK OF HIGH WINDS.
TROPICAL STORM MELISSA IS CURRENTLY LOCATED TO THE SOUTHEAST OF JAMAICA. THE
NATIONAL HURRICANE CENTER (NHC) PREDICTS THAT MELISSA IS LIKELY TO RAPIDLY
INTENSIFY AND BECOME A MAJOR HURRICANE BY EARLY NEXT WEEK AS IT REMAINS OVER
THE CARIBBEAN SEA. PLEASE REFER TO NHC FOR THE LATEST STATEMENTS AND FORECASTS
ON MELISSA. THE INTERACTION BETWEEN THE AMPLIFYING MID-LEVEL TROUGH AND THE
RESULTING LOW PRESSURE SYSTEM NEAR THE EAST COAST AND TROPICAL CYCLONE MELISSA
IS HIGHLY UNCERTAIN AT THIS TIME. HOWEVER, ENSEMBLE MEANS DEPICT ENHANCED LOW
TO MID-LEVEL MOISTURE SPREADING NORTHWEST TO THE NORTHEAST BY WEEK-2. THIS WAS
ONE FACTOR IN MAINTAINING A MODERATE RISK OF HEAVY PRECIPITATION FOR PORTIONS
OF THE NORTHEAST THROUGH OCTOBER 31ST.
SURFACE HIGH PRESSURE, ACCOMPANIED BY COOLER-THAN-NORMAL TEMPERATURES, IS
FORECAST TO SHIFT SOUTHWARD TO THE SOUTHEAST WHICH FAVORS A CHILLY HALLOWEEN
FOR THIS REGION. ON OCT 31 AND NOV 1, A SLIGHT RISK OF MUCH BELOW-NORMAL
TEMPERATURES IS POSTED WHERE THE GEFS AND ECENS PROBABILISTIC EXTREMES TOOLS
(PETS) DEPICT MORE THAN A 20 PERCENT CHANCE OF MINIMUM TEMPERATURES FALLING
BELOW THE 15TH PERCENTILE AND 40 DEGREES. ALSO, THE SLIGHT RISK AREA IS ONLY
DESIGNATED FOR AREAS WITHOUT A FIRST FROST OF THE FALL SEASON.
AFTER A BRIEF LULL IN STORMY WEATHER FOR THE PACIFIC NORTHWEST AND NORTHERN
CALIFORNIA DURING THE EARLY TO MIDDLE PART OF NEXT WEEK, A LONGWAVE TROUGH OVER
THE NORTHEASTERN PACIFIC IS FORECAST TO REAMPLIFY AND SHIFT CLOSER TO THE WEST
COAST BY THE END OF OCTOBER. MODEL CONTINUITY IS EXCELLENT ON THE TIMING OF THE
RETURN OF AN INCREASED RISK OF HEAVY PRECIPITATION WITH THE INTEGRATED VAPOR
TRANSPORT TOOL (IVT) TOOLS DERIVED FROM THE ECENS AND GEFS DEPICTING GREATER
THAN A 70 PERCENT CHANCE THAT IVT VALUES EXCEED 250 KG/M/S ACROSS THE PACIFIC
NORTHWEST ON OCT 31 AND NOV 1. BASED ON THE EVOLVING LONGWAVE PATTERN, IVT
TOOL, AND A BLEND OF THE GEFS/ECENS PROBABILISTIC EXTREMES TOOLS (PETS) HAVING
NEAR A 40 PERCENT CHANCE OF 3-DAY PRECIPITATION AMOUNTS EXCEEDING THE 85TH
PERCENTILE, A MODERATE RISK OF HEAVY PRECIPITATION IS MAINTAINED FOR
NORTHWESTERN OREGON AND WESTERN WASHINGTON ON OCT 31 AND NOV 1. A FLOODING
HAZARD IS NOT POSTED AS WIDESPREAD RIVER FLOORING IS NOT ANTICIPATED AT THIS
TIME. THE MODERATE RISK OF HEAVY SNOW WAS DECREASED IN COVERAGE TO ONLY INCLUDE
THE NORTHERN CASCADES BASED ON THE 0Z ECENS PROBABILITIES OF MORE THAN A FOOT
AND GEFS SWE TOOL. ADDITIONALLY, A MODERATE RISK OF HIGH WINDS IS POSTED ACROSS
PORTIONS OF WESTERN WASHINGTON AND OREGON WHERE THE ECENS PET DEPICTS NEAR A 40
PERCENT CHANCE OF WIND SPEEDS EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE AND
25-MPH. A SLIGHT RISK FOR HEAVY PRECIPITATION REMAINS POSTED ACROSS THE PACIFIC
NORTHWEST INTO NORTHERN CALIFORNIA, OCT 31-NOV 3, ALONG WITH A SLIGHT RISK FOR
HEAVY SNOW ACROSS THE NORTHERN CASCADES, AND A SLIGHT RISK OF HIGH WINDS ALONG
THE WEST COAST TO THE CALIFORNIA AND OREGON BORDER. FARTHER INLAND, THE SLIGHT
RISK OF HEAVY SNOW (OCT 31-NOV 3) WAS DECREASED TO THE NORTHERN ROCKIES BASED
ON THE LATEST MODEL GUIDANCE INCLUDING THE GEFS SWE.
STRONG ONSHORE FLOW IS FORECAST ACROSS SOUTHEASTERN ALASKA TIED TO THE
AFOREMENTIONED TROUGHING OVER THE NORTHEAST PACIFIC. BASED ON GOOD AGREEMENT
BETWEEN THE ECENS AND GEFS PET WITH A 20 TO 40 PERCENT CHANCE THAT 3-DAY
PRECIPITATION AMOUNTS EXCEED THE 85TH PERCENTILE, A SLIGHT RISK OF HEAVY
PRECIPITATION IS WARRANTED FOR SOUTHEASTERN ALASKA THROUGH AT LEAST THE EARLY
PART OF WEEK-2. WITH THE ECENS AND GEFS IN GOOD AGREEMENT THAT AN AMPLIFIED
500-HPA TROUGH REMAINS ANCHORED OVER THE ALASKA PENINSULA WELL INTO THE FIRST
WEEK OF NOVEMBER, THE SLIGHT RISK OF HEAVY PRECIPITATION IS VALID THROUGH THE
END OF WEEK-2. MOUNTAIN SNOW IS LIKELY ACROSS THE HIGH ELEVATION AREAS OF
SOUTHERN MAINLAND ALASKA AND SOUTHEAST ALASKA, SUPPORTING A SLIGHT RISK FOR
HEAVY SNOW FOR THE SAME TIME PERIOD. MANY OF THE ECENS ENSEMBLE MEMBERS DEPICT
SURFACE LOW PRESSURE BELOW 968-HPA CENTERED OVER THE GULF OF ALASKA, WHICH
SUPPORTS A SLIGHT RISK OF HIGH WINDS FOR SOUTHEASTERN ALASKA THROUGH NOV 1.
LATER IN WEEK-2, UNCERTAINTY ON THE STRENGTH OF ADDITIONAL LOW PRESSURE SYSTEMS
PRECLUDES EXTENDING THE SLIGHT RISK OF HIGH WINDS BEYOND DAY 9.
FORECASTER: BRAD PUGH
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