166
FXUS21 KWNC 242045
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST DECEMBER 24 2025
SYNOPSIS: CONTINUED MID-LEVEL HIGH PRESSURE OVER EASTERN SIBERIA AND MID-LEVEL
LOW PRESSURE OVER THE GULF OF ALASKA IS FAVORED TO KEEP VERY COLD AIR IN PLACE
OVER MUCH OF ALASKA, WHILE STRONG PRESSURE CONTRASTS AT THE SURFACE BETWEEN THE
WARMER OCEAN AND THE FRIGID INTERIOR PROMOTE STRONG WINDS ALONG THE SOUTHERN
AND SOUTHEASTERN COAST OF ALASKA. MOIST ONSHORE FLOW PERSISTS OVER THE WEST
COAST, BRINGING POTENTIALLY HEAVY RAIN AND SNOW AND HIGH WINDS TO MUCH OF THE
WESTERN CONTIGUOUS U.S. (CONUS). EARLY IN WEEK-2 A SURFACE LOW PRESSURE SYSTEM
IS FAVORED TO MOVE OVER NEW ENGLAND, USHERING IN POTENTIALLY HAZARDOUS COLD AND
WINDY CONDITIONS.
HAZARDS
MODERATE RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR SOUTHERN ALASKA, THE
CENTRAL AND EASTERN INTERIOR, THE ALASKAN PENINSULA, AND THE NORTHERN
PANHANDLE, FRI-WED, JAN 2-7.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR ALL OF ALASKA WITH THE
EXCEPTION OF THE NORTH SLOPE, THU-WED, JAN 1-7.
SLIGHT RISK OF HIGH WINDS FOR THE ALASKA PENINSULA, SOUTHERN MAINLAND ALASKA,
AND SOUTHEASTERN ALASKA, THU-WED, JAN 1-7.
SLIGHT RISK OF HEAVY SNOW FOR THE SOUTHERN AND CENTRAL SIERRA NEVADAS, THU-SAT,
JAN 1-3.
SLIGHT RISK OF HEAVY SNOW FOR THE WASATCH, AND MOUNTAINS OF WESTERN COLORADO
AND SOUTHERN WYOMING, THU-MON, JAN 1-5.
SLIGHT RISK OF HEAVY SNOW FOR THE CASCADES, KLAMATH, AND NORTHERN SIERRA
NEVADAS, SAT-WED, JAN 3-7.
SLIGHT RISK OF HEAVY SNOW FOR THE NORTHERN ROCKIES, SAT-WED, JAN 3-7.
SLIGHT RISK OF HEAVY PRECIPITATION FOR CALIFORNIA SOUTH OF SAN FRANCISCO BAY
AND MUCH OF THE DESERT SOUTHWEST, WED-FRI, JAN 1-3.
SLIGHT RISK OF HEAVY PRECIPITATION FOR NORTHERN CALIFORNIA, AND WESTERN OREGON
AND WASHINGTON, FRI-WED,JAN 3-7.
SLIGHT RISK OF HIGH WINDS ALONG THE WEST COAST, THU-SUN, JAN 1-4.
SLIGHT RISK OF HIGH WINDS FOR WESTERN PORTIONS OF THE SOUTHERN AND CENTRAL
PLAINS, THU-SAT, JAN 1-3.
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE NORTHEAST,
THU-SAT, JAN 1-3.
SLIGHT RISK OF HIGH WINDS FOR PARTS OF THE GREAT LAKES AND NORTHEAST, THU-FRI,
JAN 1-2.
DETAILED SUMMARY
FOR SATURDAY DECEMBER 27 - WEDNESDAY DECEMBER 31:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY JANUARY 01 - WEDNESDAY JANUARY 07: TODAY’S MODEL SOLUTIONS ARE IN
FAIR AGREEMENT REGARDING AN ACTIVE SYNOPTIC PATTERN AS DEPICTED BY 500-HPA
HEIGHT ANOMALIES OVER THE NORTH PACIFIC AND NORTH AMERICA, HOWEVER THERE IS
QUITE A BIT OF MODEL SPREAD WITH REGARD TO THE PLACEMENT OF KEY SYNOPTIC
FEATURES THROUGHOUT THE FORECAST PERIOD. EARLY IN WEEK-2 ENSEMBLE SOLUTIONS
DEPICT AMPLIFIED RIDGING OVER EASTERN SIBERIA, WEAK TROUGHING OVER THE CANADIAN
PACIFIC COAST, MODERATE RIDGING OVER THE CENTRAL CONUS, AND AMPLIFIED TROUGHING
OVER THE NORTHEAST U.S. OF THESE FEATURES, ONLY THE SIBERIAN RIDGE AND THE
DOWNSTREAM TROUGH ARE WELL-AGREED UPON. BOTH FEATURES PERSIST THROUGHOUT THE
FORECAST PERIOD, WHILE MODEL SOLUTIONS DIVERGE SIGNIFICANTLY DOWNSTREAM BEYOND
THE OUTSET OF WEEK-2, LEADING TO LOWER FORECAST CONFIDENCE, PARTICULARLY EAST
OF THE ROCKIES.
AT THE SURFACE, HIGH PRESSURE PERSISTS ACROSS MUCH OF ALASKA AND THE YUKON
THROUGHOUT WEEK-2. CONVERSELY, MEAN LOW PRESSURE IS FAVORED IN THE GULF OF
ALASKA. THE PRESSURE GRADIENT BETWEEN THESE FEATURES BRINGS INCREASED CHANCES
FOR EPISODES OF HIGH WINDS ACROSS MUCH OF SOUTHERN ALASKA FROM THE CENTRAL
ALEUTIAN ISLANDS THROUGH SOUTHEAST ALASKA. HIGH WINDS WOULD BE PARTICULARLY
FAVORED IN GAPS AND INLETS. PROBABILISTIC EXTREMES TOOLS (PETS) SHOW ENHANCED
CHANCES OF WIND SPEEDS EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE. THEREFORE,
A SLIGHT RISK OF HIGH WINDS IS POSTED FOR MOST OF SOUTHERN AND SOUTHEASTERN
ALASKA FOR ALL OF WEEK-2.
PETS CONTINUE TO HIGHLIGHT ENHANCED CHANCES FOR TEMPERATURES TO FALL TO NEAR
HAZARDOUS THRESHOLDS ACROSS MUCH OF SOUTHERN, INTERIOR, AND SOUTHEAST ALASKA,
DRIVEN IN PART BY THE PRESSURE GRADIENT DISCUSSED ABOVE. A MODERATE RISK IS
POSTED FOR SOUTHERN ALASKA, THE CENTRAL AND EASTERN INTERIOR, THE ALASKAN
PENINSULA, AND THE NORTHERN PANHANDLE VALID JAN 2-7, WHILE A BROADER SLIGHT
RISK IS POSTED FOR ALL OF ALASKA WITH THE EXCEPTION OF THE NORTH SLOPE FOR ALL
OF WEEK-2. TEMPERATURES BETWEEN -20 DEG F AND -35 DEG F ARE PREDICTED TO BE
WIDESPREAD ACROSS MUCH OF INLAND ALASKA, WITH -40 DEG F TEMPERATURES INDICATED
BY THE PETS OVER THE EASTERN INTERIOR TO THE NORTH OF FAIRBANKS. CLOSER TO THE
COAST, TEMPERATURES ARE EXPECTED TO RANGE BETWEEN 0 AND -15 DEG F (ANCHORAGE
NEAR -10 DEG F), WHILE THE SOUTHERN HALF OF SOUTHEAST ALASKA IS PREDICTED TO BE
SOMEWHAT MILDER, WITH HIGH TEMPERATURES ABOUT +10 DEG F. THE COMBINATION OF
VERY COLD WEATHER AND HIGH WINDS ALONG THE SOUTHERN TIER OF THE STATE INCREASES
THE THREAT FOR HEAVY FREEZING SPRAY AT TIMES NEAR LARGER BODIES OF WATER.
THE 0Z ECENS, 0Z GEFS, AND 0Z CMCE MODEL SOLUTIONS DEPICT PERSISTENT MID-LEVEL
TROUGHING OVER THE NORTH PACIFIC THROUGHOUT THE FORECAST PERIOD. THE INTEGRATED
VAPOR TRANSPORT (IVT) TOOL ALSO INDICATES MODERATE LOW-LEVEL MOISTURE STREAMING
INTO THE WEST COAST THROUGHOUT THE FORECAST PERIOD, WITH BOTH THE ECMWF AND
GEFS SHOWING PROBABILITIES ABOVE 40% FOR MUCH OF THE WEEK FOR IVT TO EXCEED 150
KG/M/S. TODAY’S FORECAST SOLUTIONS INITIALLY PLACE THE HEAVIEST PRECIPITATION
OVER THE SOUTHWESTERN CONUS, THEN GRADUALLY SHIFT BACK NORTH OVER THE PACIFIC
NORTHWEST. THE PETS AND UNCALIBRATED PRECIPITATION GUIDANCE SUPPORTS A SLIGHT
RISK OF HEAVY PRECIPITATION FOR CALIFORNIA SOUTH OF THE GOLDEN GATE AS WELL AS
MUCH OF THE DESERT SOUTHWEST FOR JAN 1-3, AS WELL AS A SLIGHT RISK FOR NORTHERN
CALIFORNIA, AND WESTERN OREGON AND WASHINGTON FOR JAN 3-7.
THE INCOMING MOISTURE ASSOCIATED WITH THIS ATMOSPHERIC RIVER IS LIKELY TO PUSH
WELL INLAND, RESULTING IN POTENTIALLY HEAVY SNOW FOR MANY MOUNTAIN RANGES
ACROSS THE WEST. UNCALIBRATED PROBABILITIES FROM BOTH THE ECENS AND GEFS FOR
DAILY ACCUMULATIONS OF OVER 6 INCHES EXCEED 40% IN SOME LOCATIONS THROUGHOUT
THE WEEK, AND THE GEFS PET FOR SNOW WATER EQUIVALENT (SWE) INDICATES AT LEAST A
20% CHANCE OF 3-DAY SWE TO EXCEED THE 85TH CLIMATOLOGICAL PERCENTILE AND AT
LEAST 1 INCH FOR MUCH OF THE SOUTHERN CASCADES, SIERRAS, AND NORTHERN AND
CENTRAL ROCKIES DURING VARIOUS PORTIONS OF WEEK-2. BASED ON THE GEFS PET AND
UNCALIBRATED DAILY SNOWFALL TOTALS, A SLIGHT RISK OF HEAVY SNOW IS POSTED FOR
JAN 1-3 COVERING THE SOUTHERN AND CENTRAL SIERRA NEVADAS, AND JAN 3-7 FOR THE
CASCADES, KLAMATH, AND NORTHERN SIERRAS. FURTHER EAST, A SLIGHT RISK OF HEAVY
SNOW FOR THE WASATCH, AND MOUNTAINS OF WESTERN COLORADO AND SOUTHERN WYOMING IS
INDICATED FOR JAN 1-5. ADDITIONALLY, A SLIGHT RISK IS POSTED FOR MUCH OF THE
NORTHERN ROCKIES VALID JAN 3-7.
ALONG WITH HEAVY PRECIPITATION AND SNOW, HIGH WINDS REACHING HAZARDOUS CRITERIA
ARE ALSO POSSIBLE ASSOCIATED WITH THIS ATMOSPHERIC RIVER (AR) EVENT. MODEL
ENSEMBLE MAXIMUM WIND SPEEDS FROM THE ECMWF AND GEFS EXCEED 20MPH ALONG THE
ENTIRE WEST COAST DURING THE FIRST HALF OF WEEK-2, WARRANTING A SLIGHT RISK OF
HIGH WIND ALONG THE COAST COVERING THE PERIOD JAN 1-4. FURTHER INLAND, SURFACE
LOW PRESSURE IN THE LEE OF THE ROCKIES EARLY IN THE FORECAST PERIOD IS FAVORED
TO ENHANCE WINDS OVER PORTIONS OF THE GREAT PLAINS. BASED ON ENSEMBLE MEAN WIND
SPEEDS FROM THE GEFS AND ECMWF, A SLIGHT RISK OF HIGH WINDS IS POSTED FOR
WESTERN PORTIONS OF THE SOUTHERN AND CENTRAL PLAINS FOR JAN 1-3. GIVEN A LACK
OF ANTECEDENT RAIN AND/OR SNOW, FUELS ARE UNUSUALLY DRY, ELEVATING THE
POTENTIAL FOR PRAIRIE FIRES.
EARLY IN WEEK-2 A DEEP TROUGH IS DEPICTED OVER THE NORTHEAST U.S., RESULTING IN
STRONG NORTHWESTERLY FLOW AND COLDER TEMPERATURES ACROSS THE REGION. ENSEMBLE
MEAN WIND SPEEDS APPROACH 20MPH OVER MUCH OF THE GREAT LAKES, WARRANTING A
SLIGHT RISK OF HIGH WINDS FOR JAN 1-2. PETS FOR MINIMUM TEMPERATURES ALSO
INDICATE AT LEAST A 20% CHANCE OF TEMPERATURES FALLING BELOW -10F ACROSS
NORTHERN NEW ENGLAND DURING THE FIRST HALF OF WEEK-2. WHEN PAIRED WITH ENHANCED
WINDS, APPARENT TEMPERATURES MAY FALL BELOW HAZARDOUS THRESHOLDS WHERE THESE
TWO FACTORS COMBINE, THEREFORE A SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES
IS POSTED FOR NON-COASTAL PORTIONS OF NORTHERN NEW ENGLAND FOR JAN 1-3.
FORECASTER: DANNY BARANDIARAN
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