753
FXUS21 KWNC 231811
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT SEPTEMBER 23 2026
SYNOPSIS: A SERIES OF SURFACE LOWS AND ACCOMPANYING FRONTS MAY BRING PERIODS OF
UNSETTLED WEATHER TO PARTS OF THE EASTERN U.S. DURING WEEK-2. THERE MAY BE
EPISODES OF ENHANCED MOIST FLOW TO PARTS OF THE SOUTHEASTERN U.S., WITH THE
GREATEST LIKELIHOOD OF HEAVY RAIN ACROSS THE GULF COAST AND FLORIDA PENINSULA.
SURFACE LOW PRESSURE ALONG THE WEST COAST MAY BRING EPISODIC HIGH WINDS TO
COASTAL CALIFORNIA AND SOUTHWEST OREGON. SURFACE LOW PRESSURE IN THE GULF OF
ALASKA SUPPORTS A SLIGHT RISK OF HIGH WINDS TO COASTAL PORTIONS OF
SOUTH-CENTRAL AND SOUTHEASTERN ALASKA AT THE BEGINNING OF WEEK-2, WITH ENHANCED
PRECIPITATION POSSIBLE ACROSS SOME AREAS.
HAZARDS
SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION FOR PARTS OF THE GULF COAST AND
FLORIDA PENINSULA, THU-MON, OCT 1-OCT 5.
SLIGHT RISK OF HIGH WINDS FOR PARTS OF THE CALIFORNIA AND SOUTHWESTERN OREGON
COAST, THU-SAT, OCT 1-3.
SLIGHT RISK OF EPISODIC HIGH WINDS ACROSS COASTAL PORTIONS OF SOUTH-CENTRAL AND
SOUTHEASTERN ALASKA, FRI-SUN, OCT 2-4.
DETAILED SUMMARY
FOR SATURDAY SEPTEMBER 26 - WEDNESDAY SEPTEMBER 30:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY OCTOBER 01 - WEDNESDAY OCTOBER 07: A MORE AMPLIFIED PATTERN IS
FAVORED BY MULTIPLE MODEL ENSEMBLE MEANS COMPARED TO YESTERDAY. OVERALL,
MID-LEVEL TROUGHS ARE ANTICIPATED ACROSS THE WEST COAST AND EASTERN CONUS AT
THE ONSET OF WEEK-2, RETROGRADING AT THE BEGINNING OF THE PERIOD BEFORE
PROPAGATING EASTWARD BY MID WEEK-2. THERE IS A FAIR AMOUNT OF DISAGREEMENT
REGARDING THE AMPLITUDE AND EVOLUTION OF THE TROUGH OVER THE EAST, TRANSLATING
TO DIFFERENCES IN THE SURFACE PATTERN AND HOW SURFACE LOWS AND FRONTS WILL
IMPACT THE EASTERN CONUS. THE ECENS AND CMCE ARE MORE AMPLIFIED THAN THE GEFS,
SUPPORTING A WETTER SOLUTION ACROSS THE EAST AT THE START OF THE PERIOD.
MULTIPLE MODELS INDICATE SURFACE HIGH PRESSURE BUILDING ACROSS MUCH OF THE EAST
AS AN INITIAL FRONT AHEAD OF THE MID-LEVEL TROUGH MOVES OFF THE COAST, WHICH
WOULD LEAD TO DRIER CONDITIONS ACROSS THE REGION. PERIODS OF SOUTHERLY MOIST
FLOW FROM THE GULF MAY STILL BRING EPISODES OF LOCALIZED HEAVY RAINFALL TO
PARTS OF THE GULF COAST AND FLORIDA, THEREFORE A SLIGHT RISK OF HEAVY
PRECIPITATION IS DESIGNATED FOR THESE AREAS OCT 1-5. THE REDUCTION IN COVERAGE
COMPARED TO YESTERDAY IS DUE TO MUCH OF THE RAINFALL TIMING OUT BY WEEK-2 WITH
THE GREATEST RISK OCCURRING AT THE END OF WEEK-1. THE PROBABILISTIC EXTREMES
TOOLS (PETS) CONTINUE TO SHOW BROAD COVERAGE ACROSS THE SOUTHEASTERN U.S. WITH
POSSIBLE 3-DAY ACCUMULATIONS EXCEEDING THE 85TH PERCENTILE AND ONE INCH, BUT
UNCALIBRATED GUIDANCE GENERALLY FAVORS LESS WIDESPREAD HEAVY RAINFALL. RAINFALL
WOULD BE BENEFICIAL IN AREAS WHERE ANTECEDENT CONDITIONS HAVE BEEN DRY. SOME
AREAS OF HEAVY RAIN INCLUDING POTENTIAL THUNDERSTORMS ARE POSSIBLE IN THESE
AREAS, POTENTIALLY TRIGGERING ISOLATED FLASH FLOODING, ALTHOUGH NO PARTICULAR
AREA APPEARS VULNERABLE TO WIDESPREAD AND PERSISTENT FLOOD CONDITIONS.
POTENTIAL SURFACE LOW FORMATION OVER BAJA CALIFORNIA AND ALONG THE WEST COAST
(WHICH MAY BE ENHANCED BY TROPICAL CYCLONES NEARING BAJA CALIFORNIA) COMBINED
WITH ADJACENT SURFACE HIGH PRESSURE NEAR OR JUST OFFSHORE THE WEST COAST, MAY
RESULT IN A TIGHT PRESSURE GRADIENT ACROSS PORTIONS OF THE WEST COAST. THIS
PATTERN MAY BRING IN PERIODS OF ENHANCED WIND SPEEDS ACROSS COASTAL PORTIONS OF
CALIFORNIA AND SOUTHWEST OREGON, THUS A SLIGHT RISK OF EPISODIC HIGH WINDS IS
DESIGNATED FOR THESE AREAS, OCT 1-3 WHEN THE PATTERN LOOKS MOST FAVORABLE
SUPPORTING GUSTY CONDITIONS. THIS IS SUPPORTED BY THE PETS INDICATING AT LEAST
A 20% CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 25 MPH (35 MPH
LOCALLY) AND MODEL ENSEMBLES SHOWING INCREASED CHANCES OF WIND GUSTS EXCEEDING
34 KNOTS (ABOUT 40 MPH) IN THE REGION.
MID-LEVEL TROUGHING IS EXPECTED TO BE CENTERED OVER ALASKA AND THE GULF OF
ALASKA THROUGHOUT WEEK-2, SUPPORTING SURFACE LOW FORMATION IN THE GULF OF
ALASKA. THIS SURFACE LOW MAY BRING GUSTY CONDITIONS TO SOUTHERN PORTIONS OF THE
STATE. DUE TO GOOD DAY TO DAY MODEL CONSISTENCY AND AGREEMENT AMONG MODELS, BUT
WITH SOME UNCERTAINTY AS TO WHETHER WIND SPEEDS WILL EXCEED HAZARD THRESHOLDS,
A SLIGHT RISK OF EPISODIC HIGH WINDS IS POSTED FOR COASTAL PORTIONS OF
SOUTH-CENTRAL AND SOUTHEASTERN ALASKA, OCT 2-4. THE PETS INDICATE AT LEAST A
20% CHANCE OF WIND SPEEDS REACHING THE 85TH PERCENTILE AND 40 MPH, FURTHER
SUPPORTED BY RECENT DETERMINISTIC GUIDANCE SHOWING THESE GUSTY CONDITIONS.
LOCALIZED ENHANCED HEAVY PRECIPITATION IS ALSO POSSIBLE ACROSS SOME OF THESE
AREAS ALTHOUGH TOTALS DO NOT REACH HAZARDOUS CRITERIA AT THIS TIME.
FORECASTER: MELISSA OU
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