261
FXUS21 KWNC 252022
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST JANUARY 25 2024
SYNOPSIS: AMPLIFIED MID-LEVEL LOW PRESSURE CENTERED OVER THE WEST COAST FAVORS
A STORMY PERIOD FOR PORTIONS OF THE WEST FROM THE END OF WEEK-1 CONTINUING INTO
SOME OF WEEK-2, WITH THE GREATEST ODDS FOR HIGH WINDS, HEAVY PRECIPITATION, AND
HIGH-ELEVATION SNOW ACROSS THE SOUTHWESTERN QUADRANT OF THE LOWER 48. PERIODS
OF HEAVY PRECIPITATION ARE POSSIBLE ACROSS THE SOUTHEASTERN CONTIGUOUS U.S. AS
THE MID-LEVEL LOW SHIFTS EASTWARD. MUCH BELOW NORMAL TEMPERATURES DURING WEEK-1
OVER CENTRAL AND SOUTHWESTERN ALASKA MAY LINGER INTO THE BEGINNING OF WEEK-2,
WITH HIGH WINDS POSSIBLE AT THE SAME TIME IN FAR SOUTHWESTERN PARTS OF THE
STATE AND THE ALEUTIANS.
HAZARDS
HIGH RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE CENTRAL GREAT BASIN, FOUR
CORNERS, AND SOUTHERN CALIFORNIA, FRI-MON, FEB 2-5.
MODERATE RISK OF HEAVY PRECIPITATION FOR MANY PARTS OF THE SOUTHWESTERN
QUADRANT OF THE CONUS, FRI-TUE, FEB 2-6.
SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION FOR MUCH OF THE WESTERN CONUS,
FRI-TUE, FEB 2-6.
HIGH RISK OF HEAVY SNOW FOR PARTS OF THE CENTRAL GREAT BASIN AND NORTH-CENTRAL
ARIZONA, FRI-SUN, FEB 2-4.
MODERATE RISK OF HEAVY SNOW FOR PARTS OF THE CENTRAL GREAT BASIN, SIERRA
NEVADA, NORTHERN ARIZONA, AND CENTRAL AND SOUTHERN ROCKIES, FRI-MON, FEB 2-5.
SLIGHT RISK OF PERIODS OF HEAVY SNOW ACROSS THE INTERIOR WEST, KLAMATH
MOUNTAINS, AND SIERRA NEVADA, FRI-THU, FEB 2-8.
MODERATE RISK OF HIGH WINDS ALONG THE SOUTHERN COAST OF CALIFORNIA AND PORTIONS
OF ARIZONA AND NEW MEXICO, FRI-SUN, FEB 2-4.
SLIGHT RISK OF HIGH WINDS FOR MUCH OF THE SOUTHWESTERN QUADRANT OF THE CONUS,
INCLUDING THE CENTRAL GREAT BASIN AND CENTRAL AND SOUTHERN PLAINS, FRI-SUN,
FEB 2-4.
MODERATE RISK OF PERIODS OF HEAVY PRECIPITATION FOR THE LOWER MISSISSIPPI AND
TENNESSEE VALLEYS AND ADJACENT SOUTHEAST, FRI-TUE, FEB 2-6.
SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION FOR MANY PARTS OF THE
SOUTHEASTERN QUADRANT OF THE CONUS, FRI-TUE, FEB 2-6.
SLIGHT RISK OF MUCH BELOW NORMAL TEMPERATURES FOR MUCH OF CENTRAL AND
SOUTHWESTERN MAINLAND ALASKA, FRI-SAT, FEB 2-3.
SLIGHT RISK OF HIGH WINDS FOR KODIAK ISLAND, SOUTHWESTERN MAINLAND ALASKA, AND
PARTS OF THE ALEUTIANS, FRI-SAT, FEB 2-3.
POSSIBLE FLOODING FOR MUCH OF ARIZONA AND ADJACENT NEW MEXICO.
POSSIBLE FLOODING FOR PARTS OF WESTERN CALIFORNIA.
POSSIBLE FLOODING FOR THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS AND ALABAMA.
DETAILED SUMMARY
FOR SUNDAY JANUARY 28 - THURSDAY FEBRUARY 01:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY FEBRUARY 02 - THURSDAY FEBRUARY 08: THERE CONTINUES TO BE GOOD
AGREEMENT IN MULTIPLE MODEL ENSEMBLE MEANS INDICATING AMPLIFIED MID-LEVEL
TROUGHING SHIFTING FROM NEAR THE WEST COAST LATE IN WEEK-1 TO BEING CENTERED
OVER THE COAST BY THE BEGINNING OF WEEK-2, GRADUALLY WEAKENING AS IT SHIFTS
EASTWARD. THE GREATEST IMPACTS FROM THE ASSOCIATED STORMY PATTERN ARE
ANTICIPATED FOR THE SOUTHWESTERN QUADRANT OF THE CONUS DAYS 8 TO 12 (FEB 2-6).
IN GENERAL RELATED HAZARDS ACROSS THE WEST HAVE BEEN TRIMMED FURTHER SOUTH
COMPARED TO YESTERDAY’S OUTLOOK.
THE ECENS PROBABILISTIC EXTREMES TOOL (PET) SHOWS SIGNIFICANTLY HIGHER CHANCES
FOR HEAVY PRECIPITATION COMPARED TO THE GEFS AND CANADIAN COUNTERPARTS, WITH
THE GEFS HAVING THE WEAKEST SIGNAL. A HIGH RISK OF HEAVY PRECIPITATION IS
DESIGNATED FOR PORTIONS OF THE CENTRAL GREAT BASIN, FOUR CORNERS, AND SOUTHERN
CALIFORNIA, FEB 2-5, PRIMARILY BASED ON WHERE THE ECENS PET INDICATES AT LEAST
A 60% CHANCE OF 3-DAY LIQUID EQUIVALENT EXCEEDING THE 85TH PERCENTILE
CLIMATOLOGICALLY (GREATER THAN ONE INCH ACROSS CALIFORNIA AND ARIZONA, HALF AN
INCH ELSEWHERE). A MODERATE RISK FOR HEAVY PRECIPITATION IS POSTED FOR MANY
PARTS OF THE SOUTHWESTERN QUADRANT OF THE CONUS, FEB 2-6, WHERE AT LEAST THE
GEFS, ECENS, AND CANADIAN PETS INDICATE AT LEAST A 40% CHANCE OF EXCEEDING
THESE THRESHOLDS. A BROADER SLIGHT RISK (>20% CHANCE) AREA IS HIGHLIGHTED
ACROSS MUCH OF THE CONUS FROM THE ROCKIES WESTWARD. FOR HEAVY SNOW, A HIGH RISK
(>60% CHANCE) IS POSTED FOR PARTS OF THE CENTRAL GREAT BASIN AND NORTH-CENTRAL
ARIZONA, FEB 2-4, WITH A SMALLER AREA HIGHLIGHTED WITH MODERATE RISK (>40%
CHANCE) ACROSS PARTS OF THE CENTRAL GREAT BASIN, SIERRA NEVADA, NORTHERN
ARIZONA, AND CENTRAL AND SOUTHERN ROCKIES, FEB 2-5. A BROAD AREA OF SLIGHT RISK
IS EXTENDED A DAY IN TIME COMPARED TO YESTERDAY (FEB 2-8) ACROSS THE INTERIOR
WEST, KLAMATH MOUNTAINS, AND SIERRA NEVADA THROUGHOUT WEEK-2, WITH UPSLOPE SNOW
POSSIBLE ACROSS THE ROCKIES. THE PETS DEPICT THESE HEAVY SNOW RISK AREAS
RECEIVING 3-DAY SNOW WATER EQUIVALENT TOTALS EXCEEDING THE 85TH PERCENTILE AND
HALF AN INCH, ONE INCH LOCALLY. FLOODING IS POSSIBLE ACROSS PARTS OF WESTERN
CALIFORNIA, ARIZONA, AND ADJACENT NEW MEXICO DUE TO ANTECEDENT HEAVY
PRECIPITATION DURING WEEK-1 AND EXPECTED CONTINUING HEAVY PRECIPITATION DURING
WEEK-2.
POSSIBLE SURFACE LOW FORMATION ACROSS THE SOUTHWEST IN TANDEM WITH SURFACE HIGH
PRESSURE BUILDING ACROSS THE NORTHWEST MAY LEAD TO TIGHT PRESSURE GRADIENTS
ACROSS THE SOUTHWESTERN CONUS. MODERATE RISKS FOR HIGH WINDS ARE DESIGNATED FOR
THE SOUTHERN COAST OF CALIFORNIA AND PORTIONS OF ARIZONA AND NEW MEXICO, FEB
2-4, WHERE THE ECENS PET SHOWS AT LEAST A 40% CHANCE OF WIND SPEEDS EXCEEDING
THE 85TH PERCENTILE. A BROADER AREA IS HIGHLIGHTED WITH A SLIGHT RISK OF HIGH
WINDS ACROSS MUCH OF THE SOUTHWESTERN QUADRANT OF THE CONUS, INCLUDING THE
CENTRAL GREAT BASIN AND CENTRAL AND SOUTHERN PLAINS FOR THE SAME PERIOD, WHERE
ENHANCED WINDS ARE POSSIBLE AS SURFACE LOWS OVER THE SOUTHWEST SHIFT EASTWARD.
AS THE MID-LEVEL TROUGH SHIFTS EASTWARD, ASSOCIATED SURFACE LOWS AND FRONTS ARE
PREDICTED TO MOVE FROM THE SOUTHWESTERN CONUS EASTWARD, BRINGING INCREASED
CHANCES FOR HEAVY PRECIPITATION TO PARTS OF THE LOWER MISSISSIPPI VALLEY AND
ADJACENT AREAS. HOWEVER, THERE IS SIGNIFICANTLY MORE UNCERTAINTY IN THE MODELS
REGARDING THE EVOLUTION OF THESE FEATURES TRANSLATING INTO LOWER CONFIDENCE IN
RESULTANT HAZARDS. DESPITE THE LACK OF ELEVATED CHANCES IN THE PETS, A MODERATE
RISK OF PERIODS OF HEAVY PRECIPITATION IS SPECIFIED FOR THE LOWER MISSISSIPPI
AND TENNESSEE VALLEYS AND ADJACENT SOUTHEAST, FEB 2-6, BASED ON RAW
PRECIPITATION OUTPUT FROM THE ENSEMBLE MEANS AND ANTECEDENT CONDITIONS
FEATURING SATURATED SOILS AND ELEVATED RIVER LEVELS WHICH SUPPORT A MODERATE
RISK. A BROADER SLIGHT RISK AREA IS HIGHLIGHTED ACROSS MANY PARTS OF THE
SOUTHEASTERN QUADRANT OF THE CONUS BASED ON WHERE PETS SHOW AT LEAST A 20%
CHANCE OF 3-DAY PRECIPITATION TOTALS EXCEEDING THE 85TH PERCENTILE AND ONE
INCH. A POSSIBLE FLOOD RISK IS DESIGNATED PRIMARILY WHERE THERE IS A MODERATE
RISK OF HEAVY PRECIPITATION AND THE NATIONAL WATER CENTER SHOWS POSSIBLE
FLOODING LEADING UP TO WEEK-2 ON THEIR EXPERIMENTAL FLOOD HAZARD OUTLOOK.
A BROAD AREA OF SURFACE HIGH PRESSURE ACROSS MUCH OF THE ALASKA MAINLAND IS
PREDICTED TO POSSIBLY CONTINUE FROM THE END OF WEEK-1 INTO THE START OF WEEK-2,
SUPPORTING ELEVATED POTENTIAL FOR LINGERING MUCH BELOW NORMAL TEMPERATURES
ACROSS THE REGION. THE MODERATE RISK FOR MUCH BELOW NORMAL TEMPERATURES FROM
YESTERDAY’S OUTLOOK IS NO LONGER INCLUDED IN TODAY’S, AND THE SLIGHT RISK IS
CONTINUED ACROSS CENTRAL AND SOUTHWESTERN ALASKA, FEB 2-3, WHERE PETS SHOW AT
LEAST A 20% CHANCE OF MINIMUM TEMPERATURES FALLING BELOW THE LOWEST 10TH
PERCENTILE CLIMATOLOGICALLY. TEMPERATURES ARE ANTICIPATED TO MODERATE
THEREAFTER AS SURFACE LOW PRESSURE APPROACHES THE MAINLAND FROM THE BERING SEA.
A TIGHT PRESSURE GRADIENT IS POSSIBLE BETWEEN THIS SURFACE LOW AND THE COLD
SURFACE HIGH PRESSURE SYSTEM FARTHER NORTH OVER THE MAINLAND, SUPPORTING THE
CONTINUATION OF A SLIGHT RISK OF HIGH WINDS ACROSS VALLEY GAPS ON KODIAK
ISLAND, THE SOUTHWESTERN MAINLAND, AND THE ALEUTIANS NORTHEAST OF COLD BAY, FEB
2-3.
FORECASTER: MELISSA OU
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