633
FXUS21 KWNC 121800
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 12 2025
SYNOPSIS: A STRONG AREA OF MID-LEVEL LOW PRESSURE IS EXPECTED TO MOVE INTO THE
BERING SEA AND EVENTUALLY THE GULF OF ALASKA, CONTINUING A STORMY TREND ACROSS
SOUTHWESTERN ALASKA. THIS WILL BRING INCREASED CHANCES FOR HIGH WINDS AND HEAVY
PRECIPITATION TO PARTS OF THE STATE. AN AREA OF MID-LEVEL LOW PRESSURE OVER THE
WESTERN AND CENTRAL CONTIGUOUS U.S (CONUS) IS EXPECTED TO BRING INCREASED
CHANCES OF HIGH ELEVATION HEAVY SNOWFALL AND HIGH WINDS OVER THE INTERIOR WEST
AND INTO THE HIGH PLAINS. RISING MID-LEVEL PRESSURE OVER THE NORTHEASTERN CONUS
IS EXPECTED TO QUELL ANY REMAINING HIGH WIND AND HEAVY PRECIPITATION RISKS. 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 WEEK.
HAZARDS
MODERATE RISK OF HIGH WINDS FOR THE ALEUTIANS, ALASKA PENINSULA, AND BERING SEA
COAST OF MAINLAND ALASKA, MON-WED, OCT 20-22.
SLIGHT RISK OF HIGH WINDS FOR ALEUTIANS, SOUTHERN MAINLAND, AND PARTS OF
SOUTHEAST ALASKA, MON-FRI, OCT 20-24.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE SOUTHERN MAINLAND AND SOUTHEAST
ALASKA, MON-FRI, OCT 20-24.
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,
MON-WED, OCT 20-22.
SLIGHT RISK OF HIGH WINDS FOR MANY PARTS OF THE INTERIOR WEST AND PLAINS,
MON-WED, OCT 20-22.
RAPID ONSET DROUGHT (ROD) RISK FOR PORTIONS OF THE SOUTHERN PLAINS AND THE
LOWER MISSISSIPPI VALLEY.
DETAILED SUMMARY
FOR WEDNESDAY OCTOBER 15 - SUNDAY OCTOBER 19:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR MONDAY OCTOBER 20 - SUNDAY OCTOBER 26: THE MEAN WEEK-2 500-HPA HEIGHT
ANOMALIES ACROSS THE CONTIGUOUS U.S. (CONUS) ARE FORECAST TO BE RELATIVELY
ZONAL BY MOST OF THE GUIDANCE. AN ANOMALOUS TROUGH IS FORECAST OVER THE BERING
SEA, BRINGING ENHANCED ONSHORE FLOW INTO SOUTHERN ALASKA AND BRITISH COLUMBIA,
WITH SOME TOOLS BRINGING THIS ENHANCED FLOW INTO THE PACIFIC NORTHWEST AS WELL.
A WEAK NEGATIVE NORTH ATLANTIC OSCILLATION (-NAO) IS FAVORED BY THE FORECAST
GUIDANCE, BUT TOOLS HAVE SUBSTANTIALLY BACKED OFF ON THE -NAO SIGNAL RELATIVE
TO YESTERDAY.
HOWEVER, THE DAILY PROGRESSION OF THIS PATTERN IS MORE AMPLIFIED RELATIVE TO
THE WEEK-2 MEAN. A ROBUST WAVE TRAIN IS FORECAST IN THE TOOLS FOR THE PERIOD,
WITH WEEK-2 STARTING OUT WITH POSITIVE ANOMALIES ACROSS THE NORTHEASTERN
PACIFIC, EAST COAST OF THE CONUS AND GREENLAND, WITH NEGATIVE ANOMALIES OVER
THE BERING SEA, MUCH OF THE NORTHWESTERN AND CENTRAL CONUS, AND OFF THE EAST
COAST. THE PATTERN GENERALLY FLATTENS AND THEN BECOMES MORE AMPLIFIED AGAIN BY
THE SECOND HALF OF WEEK-2, BUT WITH POSITIVE ANOMALIES ACROSS THE WEST AND
NEGATIVE ANOMALIES OVER THE GREAT LAKES AND NORTHEAST. NEGATIVE 500-HPA HEIGHT
ANOMALIES REMAIN ROBUST OVER THE BERING SEA, BUT DO EXPAND INTO THE GULF OF
ALASKA OVER TIME.
THE MOST CONFIDENT FORECAST AREA IS IN ALASKA, WHERE THERE IS STRONG AGREEMENT
ON A ROBUST MID-LEVEL TROUGH AND ASSOCIATED SURFACE LOW PRESSURE. IN THE LAST
48 HOURS, MODEL GUIDANCE HAS AMPLIFIED THE PATTERN ACROSS THIS REGION BRINGING
A STRONGER AREA OF NEGATIVE 500-HPA HEIGHT ANOMALIES INTO THE BERING SEA.
FORECAST GUIDANCE SUPPORTS INCREASED CHANCES FOR ONE OR MORE SURFACE LOW
PRESSURE SYSTEMS TO TRACK INTO THE BERING SEA AND/OR THE GULF OF ALASKA. THERE
REMAINS SOME DEGREE OF UNCERTAINTY ON THE EXACT TRACK OF ANY SURFACE LOW
PRESSURE BUT CONFIDENCE IS FAIRLY HIGH FOR A POTENTIALLY IMPACTFUL STORM
SYSTEM. THEREFORE, A MODERATE RISK OF HIGH WINDS IS POSTED FOR THE ALEUTIANS,
ALASKA PENINSULA, AND THE BERING SEA COAST AREAS, FOR OCT 20-22. A BROADER
SLIGHT RISK OF HIGH WINDS REMAINS FORECAST ENCOMPASSING THE MODERATE RISK AREA
AND EXTENDING ALONG THE SOUTHERN MAINLAND COASTLINE FOR OCT 20-24. A SLIGHT
RISK OF HEAVY PRECIPITATION IS ALSO FORECAST FOR PARTS OF SOUTHERN MAINLAND
ALASKA, FROM PRINCE WILLIAM SOUND THROUGH SOUTHEAST ALASKA FOR OCT 20-24.
PROBABILISTIC EXTREMES TOOLS (PETS) FROM THE GEFS AND ECENS SUPPORT AN ENHANCED
RISK OF 3-DAY PRECIPITATION AMOUNTS EXCEEDING THE 85TH CLIMATOLOGICAL
PERCENTILE AND 3 INCHES IN PLACES WITHIN THE HIGHLIGHTED AREA.
ACROSS THE WESTERN CONUS, MID-LEVEL TROUGHING MAY BRING MORE UNSETTLED WEATHER
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 20-22. 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. BY THE
END OF WEEK-2, THERE ARE SOME SUGGESTIONS OF A RESURGENCE IN ONSHORE FLOW INTO
THE PACIFIC NORTHWEST AND THIS WILL BE MONITORED.
IN THE CENTRAL AND EASTERN CONUS THE UNCERTAINTY IS RELATIVELY HIGH, FORECAST
GUIDANCE REMAINS INCONSISTENT RELATIVE TO PRIOR FORECASTS. MOST MODEL GUIDANCE
TODAY SUPPORTS SURFACE HIGH PRESSURE BUILDING INTO MUCH OF THE EASTERN CONUS
EARLY IN WEEK-2 FOLLOWING A FRONTAL SYSTEM AT THE END OF WEEK-1. AS SUCH, NO
PRECIPITATION OR WIND HAZARDS ARE POSTED TODAY ACROSS THE REGION.
A RAPID ONSET DROUGHT (ROD) RISK REMAINS IN EFFECT FOR MANY PARTS OF THE
SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY WHERE PRECIPITATION DEFICITS OVER
THE LAST 30 DAYS 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 AT THIS TIME. THE ENSEMBLE
MEANS FOR WEEK-2 INDICATE LESS THAN AN INCH OF PRECIPITATION AT THIS TIME.
SHOULD PRECIPITATION AMOUNTS INCREASE DURING WEEK-2 A DISCONTINUATION OF THE
ROD SHAPE WOULD BE CONSIDERED.
FORECASTER: RYAN BOLT
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