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FXUS21 KWNC 251808
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT SEPTEMBER 25 2026
SYNOPSIS: A COLD FRONT IS FORECAST TO SHIFT SOUTHWARD ACROSS THE SOUTHEAST AND
GULF COAST ON OCT 3 AND 4 WITH AN ELEVATED RISK OF HEAVY PRECIPITATION. BEHIND
THIS COLD FRONT, AT LEAST A BRIEF PERIOD OF COOLER-THAN-NORMAL TEMPERATURES ARE
EXPECTED TO OVERSPREAD THE CENTRAL U.S. THERE IS AN INCREASING CHANCE OF THE
FIRST WIDESPREAD FROST OR FREEZE OF THE SEASON FOR THE NORTHERN TO CENTRAL
GREAT PLAINS, WESTERN CORN BELT, AND UPPER MIDWEST. A SERIES OF LOW PRESSURE
SYSTEMS WITH ENHANCED ONSHORE FLOW RESULTS IN A SLIGHT RISK OF HEAVY
PRECIPITATION AND HIGH WINDS FOR SOUTH-CENTRAL AND SOUTHEASTERN ALASKA.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE SOUTHEAST AND GULF COAST,
SAT-SUN, OCT 3-4.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE FLORIDA PENINSULA, SAT-FRI, OCT 3-9.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR THE NORTHERN TO CENTRAL GREAT
PLAINS, WESTERN CORN BELT, AND UPPER MIDWEST, SUN-TUE, OCT 4-6.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF SOUTH-CENTRAL AND SOUTHEASTERN
ALASKA, SAT-FRI, OCT 3-9.
SLIGHT RISK OF HIGH WINDS FOR COASTAL PARTS OF SOUTH-CENTRAL AND SOUTHEASTERN
ALASKA, SAT-FRI, OCT 3-9.
DETAILED SUMMARY
FOR MONDAY SEPTEMBER 28 - FRIDAY OCTOBER 02:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY OCTOBER 03 - FRIDAY OCTOBER 09: THE GEFS AND ECENS ARE IN BETTER
AGREEMENT TODAY WITH AN AMPLIFYING 500-HPA RIDGE OVER WESTERN NORTH AMERICA
DURING EARLY OCTOBER, WHICH RESULTS IN A COLD FRONT ADVANCING SOUTHWARD ACROSS
THE SOUTHEAST AND LIKELY SOUTH OF THE GULF COAST BY OCT 5. AHEAD OF THE COLD
FRONT, THERE IS A SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE SOUTHEAST
AND GULF COAST ON OCT 3 AND 4. THIS IS SUPPORTED BY 24-HOUR PRECIPITATION
AMOUNTS FROM THE GEFS AND ECENS ALONG WITH GOOD MODEL CONTINUITY. THE SLIGHT
RISK OF HEAVY PRECIPITATION CONTINUES THROUGH THE END OF WEEK-2, OCT 9, ACROSS
THE FLORIDA PENINSULA AS A STATIONARY FRONT MAY BE A FOCUS FOR ENHANCED
RAINFALL ACROSS THE REGION. THE BAY OF CAMPECHE WILL HAVE TO BE CLOSELY
MONITORED FOR TROPICAL CYCLONE (TC) DEVELOPMENT THROUGH EARLY TO MID-OCTOBER.
FOLLOWING HURRICANE POLO IN THE EAST PACIFIC, THE NATIONAL HURRICANE CENTER
(NHC) STATES THAT THERE IS A 90% CHANCE OF ANOTHER TROPICAL CYCLONE (TC)
FORMING OFFSHORE OF SOUTHWESTERN MEXICO WITHIN THE NEXT WEEK. BY WEEK-2, THERE
IS A LARGE SPREAD AMONG THE GEFS AND ECENS ENSEMBLE MEMBERS ON THE EVENTUAL
TRACK OF THIS LIKELY TC. THEREFORE, UNCERTAINTY IS HIGH ON HOW MUCH IF ANY
RAINFALL SHIFTS NORTH INTO THE DESERT SOUTHWEST FROM OCT 3-9.
IN THE WAKE OF A STRONG COLD FRONT FOR EARLY OCTOBER, MULTI-MODEL ENSEMBLE MEAN
SOLUTIONS ARE IN GOOD AGREEMENT INDICATING A SURFACE HIGH SHIFTING SOUTH FROM
CANADA INTO THE NORTH-CENTRAL U.S. A SLIGHT RISK OF MUCH BELOW-NORMAL
TEMPERATURES, VALID OCT 4-6, IS POSTED FOR THE NORTHERN TO CENTRAL GREAT
PLAINS, WESTERN CORN BELT, AND UPPER MISSISSIPPI VALLEY WHERE THE ECENS
PROBABILISTIC EXTREMES TOOL (PET) DEPICTS >20% CHANCE OF MINIMUM TEMPERATURES
FALLING BELOW FREEZING AND THE 15TH PERCENTILE CLIMATOLOGICALLY. THIS WOULD BE
THE FIRST WIDESPREAD FROST AND FREEZE OF THE SEASON FOR THESE AREAS. TYPICALLY,
THE FIRST FREEZE OF THE FALL OCCURS EITHER IN LATE SEPTEMBER (NORTHERN PLAINS)
OR EARLY OCTOBER (CENTRAL PLAINS AND WESTERN CORN BELT).
A HIGHLY AMPLIFIED 500-HPA TROUGH OVER THE NORTHEAST PACIFIC IS LIKELY TO
PROMOTE A SERIES OF LOW PRESSURE SYSTEMS TO TRACK FROM THE ALASKA PENINSULA
EASTWARD TO THE GULF OF ALASKA. BASED ON THE ENHANCED ONSHORE FLOW, ASSOCIATED
WITH THESE LOW PRESSURE SYSTEMS, AND SUPPORT FROM THE ECMWF AND GEFS PETS (20%
CHANCE OF 3-DAY PRECIPITATION AMOUNTS > 85TH PERCENTILE AND 3 INCHES), A SLIGHT
RISK OF HEAVY PRECIPITATION IS DESIGNATED FROM THE KENAI PENINSULA TO
SOUTHEASTERN ALASKA. SINCE THE GEFS, ECENS, AND CMCE PERSIST THE DEEP 500-HPA
TROUGH OVER THE NORTH PACIFIC THROUGH EARLY OCTOBER, THE HEAVY PRECIPITATION
HAZARD IS MAINTAINED FOR THE ENTIRETY OF WEEK-2. ALTHOUGH MOST OF THE MODEL
ENSEMBLE MEMBERS ONLY DEPICT SURFACE LOWS OF MODERATE STRENGTH, A SLIGHT RISK
OF HIGH WINDS IS MAINTAINED BASED ON PATTERN RECOGNITION AND SUPPORT FROM THE
ECENS PET WIND TOOL. THE HIGH WIND HAZARD IS ALSO VALID FROM OCT 3-9.
FORECASTER: BRAD PUGH
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