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FXUS21 KWNC 102046
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 10 2025
SYNOPSIS: A PROGRESSIVE PATTERN LEADING TO MORE MID-LEVEL LOW PRESSURE OVER THE
WESTERN CONTIGUOUS U.S (CONUS) IS EXPECTED TO BRING INCREASED CHANCES FOR HIGH
ELEVATION HEAVY SNOWFALL AND HIGH WINDS OVER THE INTERIOR WEST, WITH HEAVY
PRECIPITATION POSSIBLE FOR PORTIONS OF THE GREAT PLAINS AND MISSISSIPPI VALLEY
DURING WEEK-2. RISING MID-LEVEL PRESSURE OVER THE EASTERN CONUS IS EXPECTED TO
QUELL ANY UNSEASONABLE COLD AIR, HOWEVER PERIODS OF HIGH WINDS REMAIN POSSIBLE
OVER THE NORTHEAST EARLY IN WEEK-2. A RAPID ONSET DROUGHT RISK REMAINS FOR
PARTS OF THE SOUTHERN PLAINS AND THE LOWER MISSISSIPPI VALLEY WHERE
ABOVE-NORMAL TEMPERATURES AND LIMITED PRECIPITATION REMAIN FORECAST DURING THE
NEXT TWO WEEKS. A STORMY PATTERN REEMERGING OVER ALASKA IS EXPECTED TO BRING
POTENTIALLY HEAVY PRECIPITATION AND HIGH WINDS FOR MOST SOUTHERN PARTS OF THE
STATE.
HAZARDS
SLIGHT RISK OF HIGH WINDS FOR THE MID-ATLANTIC AND NORTHEAST, SAT-SUN, OCT
18-19.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE NORTHERN AND CENTRAL
PLAINS, AND UPPER AND MIDDLE MISSISSIPPI VALLEY, SAT-MON, OCT 18-20.
SLIGHT RISK OF HEAVY SNOW ACROSS THE HIGHER ELEVATIONS OF THE CENTRAL AND
NORTHERN ROCKIES, AND ADJACENT PARTS OF THE GREAT BASIN AND GREAT PLAINS,
SAT-MON, OCT 18-21.
SLIGHT RISK OF HIGH WINDS FOR MANY PARTS OF THE INTERIOR WEST AND HIGH PLAINS,
SAT-MON, OCT 18-21.
SLIGHT RISK OF HIGH WINDS FOR ALEUTIANS, SOUTHERN MAINLAND, AND PARTS OF
SOUTHEAST ALASKA, SAT-WED, OCT 18-22.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE SOUTHERN MAINLAND, AND PARTS OF
SOUTHEAST ALASKA, SAT-WED, OCT 18-22.
RAPID ONSET DROUGHT (ROD) RISK FOR PORTIONS OF THE SOUTHERN PLAINS AND THE
LOWER MISSISSIPPI VALLEY.
DETAILED SUMMARY
FOR MONDAY OCTOBER 13 - FRIDAY OCTOBER 17:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY OCTOBER 18 - FRIDAY OCTOBER 24: AT THE START OF WEEK-2 (OCT 18),
THERE IS FAIR AGREEMENT IN THE 500-HPA HEIGHT ANOMALY FORECASTS FROM THE GEFS
AND ECMWF ENSEMBLES FEATURING ANOMALOUS RIDGING ACROSS THE CENTRAL CONUS,
BOOKENDED BY A PAIR OF TROUGHS OVER THE WESTERN AND EASTERN CONUS. WHILE
MULTIPLE MODELS CONTINUE TO FAVOR THE DEVELOPMENT OF A BLOCKING RIDGE FURTHER
NORTH OVER GREENLAND AND THE DAVIS STRAIT, CONSISTENT WITH A NEGATIVE NORTH
ATLANTIC OSCILLATION (-NAO) PATTERN TAKING SHAPE, THE LATEST ENSEMBLE RUNS
DEPICT A CONSIDERABLY MORE PROGRESSIVE PATTERN UNDERNEATH THIS HIGHER LATITUDE
MID-LEVEL FEATURE COMPARED TO PREVIOUS GUIDANCE. AFTER THE OUTSET OF THE
PERIOD, MUCH OF ANOMALOUS TROUGHING INITIALLY FAVORED UPSTREAM SHIFTS EASTWARD
INTO THE INTERIOR WEST, INCREASING CHANCES FOR LEE CYCLOGENESIS AND WETTER
CONDITIONS ACROSS THE GREAT PLAINS AND MISSISSIPPI VALLEY DURING THE PERIOD. IN
THE SAME VEIN, THE ANOMALOUS RIDGING IS NOW FAVORED TO SLIDE EASTWARD TO
PROMOTE GENERALLY DRIER AND WARMER CONDITIONS EAST OF THE MISSISISIPPI, THOUGH
THE 0Z GEFS AND 0Z ECMWF ARE AT ODDS WITH THE EVOLUTION OF THIS FEATURE, WITH
THE FORMER FAVORING MORE TROUGHING TO LINGER OVER THE NORTHEAST LATER IN WEEK-2.
DUE TO THIS MODEL DISAGREEMENT IN THE MID-LEVEL PATTERN OVER THE EAST,
DIFFERENCES EXIST IN BOTH THE RAW AND CALIBRATED TEMPERATURE TOOLS BETWEEN THE
GEFS AND THE ECMWF, REDUCING OUTLOOK CONFIDENCE IN REGARDS TO THE POTENTIAL FOR
ANOTHER ROUND OF ANOMALOUS COLD AIR AFFECTING THE NORTHEASTERN CONUS FOLLOWING
WEEK-1. THEREFORE, THE SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES IS
DISCONTINUED IN THE UPDATED OUTLOOK GIVEN THE NEAR TO ABOVE-NORMAL TEMPERATURES
FAVORED OVER THE GREAT LAKES, APPALACHIANS, MID-ATLANTIC, AND NORTHEAST IN THE
ECMWF EARLY IN WEEK-2. HOWEVER, A SLIGHT RISK OF HIGH WINDS REMAINS POSTED,
AND IS NOW VALID THROUGH OCT 19 BASED ON BETTER MODEL AGREEMENT WITH THE
POSITION OF THE MEAN SURFACE LOW OFFSHORE OFFSHORE OF THE CANADIAN MARITIMES
AND CONTINUED SIGNALS FOR WINDS EXCEEDING THE 85TH PERCENTILE IN THE ECMWF
PROBABILISTIC EXTREMES TOOL (PET).
WITH MID-LEVEL TROUGHING FAVORED OVER THE INTERIOR WEST, ONE OR MORE PULSES OF
SHORTWAVE ENERGY ARE POSSIBLE ALONG THE MEAN TROUGH AXIS, HELPING TO INDUCE
SURFACE LOW DEVELOPMENT ACROSS THE GREAT PLAINS DURING THE PERIOD. THIS IS
REFLECTED IN THE GEFS AND ECMWF ENSEMBLES, WHICH DEPICT AN INCREASED NUMBER OF
ENSEMBLE MEMBER LOW CENTERS ACROSS THE CENTRAL AND NORTHERN HIGH PLAINS EARLY
IN WEEK-2 SINCE YESTERDAY. WHILE THERE IS SOME QUESTION AS TO HOW WELL RETURN
FLOW FROM THE GULF WILL BE ESTABLISHED TO PUMP MOISTURE INTO THE CENTRAL CONUS,
BOTH THE GEFS AND ECMWF ENSEMBLES AGREE IN THEIR DEPICTION OF WETTER CONDITIONS
OVER THE MIDWEST EARLY IN THE PERIOD. BASED ON SOME AREAS BEING POTENTIALLY
HEAVY (20% CHANCES FOR 3-DAY AMOUNTS EXCEEDING AN INCH) IN THE RAW TOOLS, AND
SUPPORT IN THE PETS DEPICTING 20-30% FOR AMOUNTS EXCEEDING THE 85TH PERCENTILE,
A SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED MAINLY OVER THE LOWER MISSOURI
RIVER BASIN FOR OCT 18-20.
IT IS WORTH NOTING THAT THE CALIBRATED TOOLS FAVOR MORE OF A SOUTHERLY SOLUTION
OF THE HEAVY PRECIPITATION POTENTIAL OVER THE SOUTH-CENTRAL CONUS THROUGH MID
WEEK-2, HOWEVER THIS AREA IS OMITTED FOR THE TIME BEING IN DEFERENCE TO THE
DRIER CONDITIONS IN THE RAW PRECIPITATION GUIDANCE WHICH HAS SHOWN MORE SKILL
DURING THE PAST SEVERAL WEEKS. IT IS POSSIBLE THE HEAVY PRECIPITATION THREAT
MAY SHIFT SOUTHWARD ASSOCIATED WITH ANOTHER ROUND OF SURFACE LOW DEVELOPMENT
LATER IN WEEK-2, AND THIS POTENTIAL WILL BE REASSESSED IN SUBSEQUENT HAZARD
OUTLOOKS. AS SUCH, THE RAPID ONSET DROUGHT (ROD) RISK REMAINS IN EFFECT FOR
MANY PARTS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY WHERE
PRECIPITATION DEFICITS RANGE FROM 3 TO 5 INCHES, AND LITTLE PRECIPITATION AND
ABOVE NORMAL TEMPERATURES ARE FAVORED DURING WEEK-1. ANY PRECIPITATION THAT
DOES FALL WITHIN THE HIGHLIGHTED ROD DURING WEEK-2 DOESN'T APPEAR LIKELY TO
OVERCOME THE PRECIPITATION AND SOIL MOISTURE DEFICITS REGISTERED.
THE MID-LEVEL TROUGHING IS ALSO EXPECTED TO BRING MORE UNSETTLED WEATHER
UPSTREAM, ALONG WITH COLDER TEMPERATURES OVERSPREADING THE WESTERN CONUS TIED
TO THE PREVAILING NORTHWESTERLY FLOW. ALTHOUGH THESE TEMPERATURES ARE NOT
EXPECTED TO REACH HAZARDS CRITERIA FOLLOWING FIRST AUTUMN FREEZES, THE
COMBINATION OF ENHANCED TROPOSPHERIC MOISTURE AND ANOMALOUS COLD DOES SUPPORT
THE POTENTIAL FOR ACCUMULATING SNOWFALL ACROSS THE HIGHER ELEVATIONS OF THE
WEST. BASED ON THE SNOW WATER EQUIVALENT (SWE) PET FROM THE GEFS, WHICH DEPICTS
INCREASED CHANCES FOR VALUES EXCEEDING THE 85TH PERCENTILE JUST AHEAD OF THE
MEAN TROUGH AXIS, A SLIGHT RISK OF HEAVY SNOW IS ISSUED FOR PORTIONS OF THE
CENTRAL AND NORTHERN ROCKIES FOR OCT 18-21. ACCOMPANYING THIS SNOW HAZARD, A
SLIGHT RISK OF HIGH WINDS IS ALSO ISSUED COVERING A BROADER AREA WHERE THE
ECMWF PET INDICATES 20-30% CHANCES FOR WIND SPEEDS EXCEEDING THE 85TH
PERCENTILE.
AMPLIFIED TROUGHING REMAINS FAVORED TO SHIFT EASTWARD FROM THE BERING SEA AND
INTO THE GULF OF ALASKA WHICH IS EXPECTED TO SPAWN ONE OR MORE SURFACE LOWS
DURING WEEK-2. BASED ON THE LATEST PETS DEPICTING ELEVATED CHANCES OF WIND
SPEEDS EXCEEDING THE 85TH PERCENTILE AND 40MPH, A SLIGHT RISK OF HIGH WINDS
REMAINS HIGHLIGHTED FROM THE ALEUTIANS TO YAKUTAT, VALID FROM OCT 18-22. IN
ADDITION, A SLIGHT RISK OF HEAVY PRECIPITATION IS INTRODUCED FOR THE SOUTHERN
MAINLAND AND THE SOUTHEAST, ALSO VALID FOR OCT 18-22 WHERE PETS INDICATE
STRONGER CHANCES FOR 3-DAY AMOUNTS EXCEEDING 2 TO 3 INCHES RELATIVE TO
YESTERDAY.
FORECASTER: NICK NOVELLA
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