067
FXUS21 KWNC 111752
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT SEPTEMBER 11 2025
SYNOPSIS: MID-LEVEL HIGH PRESSURE ACROSS MUCH OF NORTH AMERICA DURING WEEK-2 IS
ANTICIPATED TO RESULT IN WIDESPREAD ABOVE-NORMAL TEMPERATURES. EXTREME HEAT
CONDITIONS ARE POSSIBLE ACROSS THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS,
SOUTHEAST, AND EASTERN SOUTHERN PLAINS AT THE BEGINNING OF THE PERIOD. THE
ABNORMALLY WARM TEMPERATURES, COMBINED WITH ANTECEDENT DRYNESS AND BELOW NORMAL
PRECIPITATION FAVORED DURING THE NEXT TWO WEEKS SUPPORT A RAPID ONSET DROUGHT
(ROD) RISK FOR MISSISSIPPI, ALABAMA, AND GEORGIA. LINGERING MID-LEVEL LOW
PRESSURE FORECAST OVER THE WESTERN THIRD OF THE CONUS FROM THE END OF WEEK-1
INTO THE BEGINNING OF WEEK-2 FAVORS INCREASED CHANCES FOR EPISODES OF HIGH
WINDS OVER CENTRAL PARTS OF THE WEST COAST. A STALLED FRONTAL BOUNDARY REMAINS
FORECAST ACROSS THE SOUTHEASTERN U.S. BRINGING AN INCREASED LIKELIHOOD FOR
ENHANCED PRECIPITATION TO THE REGION. EARLY IN WEEK-2, TROPICAL MOISTURE
ASSOCIATED WITH AN EASTERN PACIFIC TROPICAL CYCLONE ENHANCES THE RISK FOR HEAVY
PRECIPITATION ACROSS PORTIONS OF THE SOUTHWEST. SURFACE LOW PRESSURE IS
FORECAST TO BRING INCREASED CHANCES OF HEAVY PRECIPITATION TO COASTAL PORTIONS
OF SOUTHEASTERN ALASKA.
HAZARDS
SLIGHT RISK OF HIGH WINDS OVER PARTS OF COASTAL PORTIONS OF NORTHERN CALIFORNIA
AND SOUTHERN OREGON, FRI-SAT, SEP 19-20.
SLIGHT RISK OF EXTREME HEAT ACROSS LOWER MISSISSIPPI AND TENNESSEE VALLEYS,
SOUTHEAST, AND EASTERN SOUTHERN PLAINS, FRI-SUN, SEP 19-21.
SLIGHT RISK OF HEAVY PRECIPITATION OVER THE SOUTHWEST, FRI-SUN, SEP 19-21.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS MOST OF FLORIDA AND THE COASTAL
SOUTHEAST, FRI-TUE, SEP 19-23.
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS COASTAL PORTIONS OF THE KENAI
PENINSULA AND THE NORTHERN PORTION OF SOUTHEAST ALASKA, FRI-SAT, SEP 19-20.
RAPID ONSET DROUGHT (ROD) RISK ACROSS MISSISSIPPI, ALABAMA, AND GEORGIA
DETAILED SUMMARY
FOR SUNDAY SEPTEMBER 14 - THURSDAY SEPTEMBER 18:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY SEPTEMBER 19 - THURSDAY SEPTEMBER 25: MEAN 500-HPA HEIGHT ANOMALY
FORECASTS FROM THE 0Z GEFS, ECENS, AND CMCE ENSEMBLES SHOW THE WEEK-2 PERIOD
STARTING OFF WITH AN AMPLIFIED RIDGE CENTER OVER CANADA WHICH EXTENDS
SOUTHEASTWARD INTO MUCH OF THE NORTHERN TIER OF THE CONUS AND SOUTHEAST ALASKA.
A MID-LEVEL TROUGH CONTINUES TO BE ANTICIPATED OVER THE EASTERN BERING SEA AND
WESTERN ALASKA FROM THE END OF WEEK-2 INTO WEEK-2, WITH SEVERAL SHALLOW,
SHORTWAVE TROUGHS OVER THE NORTHWESTERN AND NORTH-CENTRAL CONUS, AND OFF THE
EAST COAST.
IN RESPONSE TO THE MID-LEVEL RIDGE AXIS EXTENDING FROM CENTRAL CANADA INTO THE
GREAT LAKES REGION LATE NEXT WEEK, BOTH RAW AND CALIBRATED TEMPERATURE TOOLS
CONTINUE TO HIGHLIGHT ELEVATED CHANCES FOR WIDESPREAD COVERAGE OF ABOVE-NORMAL
TEMPERATURES OVER MOST OF THE CENTRAL AND EASTERN CONUS. A SLIGHT RISK OF
EXTREME HEAT IS MAINTAINED OVER FAR EASTERN PARTS OF THE SOUTHERN PLAINS, MOST
OF THE LOWER HALF OF THE MISSISSIPPI VALLEY, MOST OF TENNESSEE AND ALABAMA, AND
NORTHWESTERN GEORGIA, SEP 19-21. THE GEFS/ECENS PROBABILISTIC EXTREME TOOLS
(PETS) INDICATE AT LEAST A 20% CHANCE OF MAXIMUM TEMPERATURES EXCEEDING THE
90TH PERCENTILE CLIMATOLOGICALLY, REACHING THE MIDDLE TO UPPER 90S DEG F. THE
GREATEST DEW POINT TEMPERATURES (AT LEAST 70 DEG F) CONFINED TO NEAR THE GULF
COAST, WHICH WOULD SUPPORT HIGHER HEAT INDEX VALUES. THE ECENS PET HAS
INCREASED ITS HEAT SIGNAL, WHEREAS THE GEFS COUNTERPART SLIGHTLY DECREASES IT,
RESULTING IN CONTINUED UNCERTAINTY AND RESULTANT SLIGHT RISK. ADDITIONALLY,
THE WEEK-2 MEAN TEMPERATURE SKILL WEIGHTED TOOL FAVORS THE GEFS TEMPERATURE
SOLUTION IN THE HEAT RISK AREA, PRECLUDING FAVORING THE HIGHER PROBABILITIES
FOR EXTREME HEAT IN THE ECENS.
THE COMBINATION OF 30 TO 60-DAY PRECIPITATION DEFICITS, ABOVE-NORMAL
TEMPERATURES AND BELOW-NORMAL PRECIPITATION FORECAST DURING THE NEXT TWO WEEKS
SUPPORTS A RAPID ONSET DROUGHT (ROD) RISK ACROSS MISSISSIPPI, ALABAMA, AND
GEORGIA. THE NORTHERN EXTENT OF THE ROD AREA IN PREVIOUS OUTLOOKS HAS BEEN
DECREASED DUE TO THE UPDATED DROUGHT MONITOR ALREADY HAVING MUCH OF THIS AREA
IN DROUGHT (D1). SPATIAL COVERAGE OF ROD IS EXPANDED SLIGHTLY EASTWARD AND
SOUTHWARD TODAY FOR ALABAMA AND GEORGIA WHERE 30-DAY PRECIPITATION HAS
AVERAGED BELOW NORMAL AND DRY, HOT CONDITIONS ARE ANTICIPATED. DRY VEGETATIVE
FUELS IN THIS AREA TYPICALLY MEANS INCREASED RISK OF WILDFIRES.
THERE ARE ENHANCED CHANCES FOR HEAVY PRECIPITATION OVER THREE AREAS OF THE
UNITED STATES DURING THIS HAZARDS PERIOD. THE FIRST AREA IS ALONG THE SOUTHEAST
COAST INCLUDING MOST OF FLORIDA, SEP 19-21. THIS IS RELATED TO A PREDICTED
STALLED FRONTAL BOUNDARY OVER THIS REGION, AND A WEAK MID-LEVEL TROUGH. THE
ECENS AND GEFS PETS INDICATE AT LEAST A 20% CHANCE OF 3-DAY ACCUMULATED
PRECIPITATION AMOUNTS IN EXCESS OF THE 85TH HISTORICAL PERCENTILE AND 1-INCH.
THE SECOND AREA OF FAVORED HEAVY PRECIPITATION IS CONTINUED OVER THE SOUTHWEST,
SEP 19-21, WHERE TROPICAL MOISTURE MAY STREAM INTO THIS REGION FROM THE GULF OF
CALIFORNIA, IN RELATION TO A PASSING TROPICAL CYCLONE OVER THE EASTERN PACIFIC.
AREAS OF HEAVY PRECIPITATION MAY BE LOCALIZED, AND THERE REMAINS SIGNIFICANT
UNCERTAINTY REGARDING THE SPECIFIC LOCATIONS WITH THE GREATEST AMOUNTS.
REGARDLESS OF UNCERTAINTY, THE INFLUX OF TROPICAL MOISTURE FROM PASSING
TROPICAL CYCLONES OVER THE EASTERN PACIFIC ALONG WITH TRIGGERED GULF SURGES,
ARE COMMONLY ACCOMPANIED BY FLASH AND/OR URBAN FLOODING, AND THIS POSSIBILITY
SHOULD BE MONITORED CLOSELY. THE THIRD AREA OF FAVORED HEAVY PRECIPITATION IS
ALONG THE SOUTHERN COAST OF ALASKA, FROM ABOUT THE EASTERN KENAI PENINSULA
EASTWARD TO INCLUDE APPROXIMATELY THE NORTHERN HALF OF THE ALASKA PANHANDLE,
SEP 19-20. WITH A MID-LEVEL TROUGH PREDICTED UPSTREAM OVER THE EASTERN BERING
SEA AND WESTERN ALASKA, AND SURFACE LOW PRESSURE NEAR THE ALASKA PENINSULA,
SOUTHERLY ONSHORE FLOW IS EXPECTED TO PREVAIL ACROSS THE AFOREMENTIONED PORTION
OF THE ALASKA COAST. THE GEFS AND ECENS PETS SUPPORT 3-DAY PRECIPITATION
AMOUNTS EXCEEDING THE 85TH HISTORICAL PERCENTILE, AND AT LEAST 2 INCHES (3
INCHES LOCALLY), ALBEIT WITH A DECREASE IN SPATIAL COVERAGE OF REACHING HIGHER
PRECIPITATION AMOUNTS COMPARED TO YESTERDAY.
A SLIGHT RISK OF HIGH WINDS (WIND SPEEDS IN EXCESS OF THE 85TH CLIMATOLOGICAL
PERCENTILE AND 20-25 MPH) REMAINS HIGHLIGHTED ALONG THE PACIFIC COAST OF OREGON
AND NORTHERN CALIFORNIA, SEP 19-20, ASSOCIATED WITH A MID-LEVEL TROUGH PASSING
THROUGH THE AREA AND AN ENHANCED SURFACE PRESSURE GRADIENT BETWEEN HIGH
PRESSURE OVER THE EASTERN PACIFIC AND LOW PRESSURE OVER THE INTERIOR OF THE
WEST COAST STATES.
FORECASTER: MELISSA OU
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