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FXUS21 KWNC 292102
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST JANUARY 29 2024
SYNOPSIS: TWO STORM SYSTEMS ARE PREDICTED TO AFFECT THE CONTIGUOUS U.S. (CONUS)
DURING THE WEEK-2 OUTLOOK PERIOD. THE FIRST STORM SYSTEM IS EXPECTED TO BRING A
VARIETY OF WEATHER-RELATED HAZARDS TO THE WESTERN CONUS DURING THE DURATION OF
THE OUTLOOK PERIOD. THE SECOND STORM SYSTEM IS FORECAST TO AFFECT THE CENTRAL
AND SOUTHEASTERN CONUS WITH POTENTIALLY HEAVY PRECIPITATION PRIMARILY DURING
THE MIDDLE AND LATTER PORTIONS OF WEEK-2.
HAZARDS
HIGH RISK OF HEAVY PRECIPITATION FOR THE SOUTHERN HALF OF CALIFORNIA, FAR
SOUTHERN NEVADA, AND WESTERN ARIZONA, TUE-FRI, FEB 6-9.
MODERATE RISK OF HEAVY PRECIPITATION FOR MOST OF CALIFORNIA, FAR SOUTHERN
NEVADA, AND MOST OF ARIZONA, TUE-SAT, FEB 6-10.
SLIGHT RISK OF HEAVY PRECIPITATION FOR NEARLY ALL OF CALIFORNIA, SOUTHERN AND
SOUTHWESTERN NEVADA, ARIZONA, AND WESTERN NEW MEXICO, TUE-MON, FEB 6-12.
SLIGHT RISK OF HEAVY PRECIPITATION FOR EASTERN TEXAS, THE LOWER MISSISSIPPI
VALLEY, TENNESSEE VALLEY, AND PARTS OF THE SOUTHEAST, THU-MON, FEB 8-12.
HIGH RISK OF HEAVY SNOW FOR PARTS OF THE CENTRAL GREAT BASIN AND NORTH-CENTRAL
ARIZONA, TUE-THU, FEB 6-8.
MODERATE RISK OF HEAVY SNOW FOR PARTS OF THE CENTRAL GREAT BASIN, SIERRA
NEVADA, NORTHERN ARIZONA, AND CENTRAL AND SOUTHERN ROCKIES, TUE-FRI, FEB 6-9.
SLIGHT RISK OF PERIODS OF HEAVY SNOW ACROSS THE INTERIOR WEST, KLAMATH
MOUNTAINS, AND SIERRA NEVADA, TUE-MON, FEB 6-12.
SLIGHT RISK OF HEAVY SNOW FOR PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION,
NORTHERN ROCKIES AND NORTHERN HIGH PLAINS, TUE-THU, FEB 6-8.
SLIGHT RISK OF HEAVY SNOW FROM THE CENTRAL HIGH PLAINS NORTHEASTWARD INTO THE
UPPER MISSISSIPPI VALLEY, THU-SUN, FEB 8-11.
MODERATE RISK OF HIGH WINDS FOR SOUTHERN CALIFORNIA, FAR SOUTHERN PORTIONS OF
NEVADA AND UTAH, ARIZONA, AND PARTS OF THE SOUTHERN ROCKIES, TUE-FRI, FEB 6-9.
SLIGHT RISK OF HIGH WINDS FROM CALIFORNIA EASTWARD ACROSS THE FOUR CORNERS
STATES, CENTRAL AND SOUTHERN PLAINS, AND INTO THE MIDDLE AND LOWER MISSISSIPPI
VALLEY, TUE-MON, FEB 6-12.
POSSIBLE FLOODING FOR COASTAL PARTS OF CENTRAL AND SOUTHERN CALIFORNIA.
POSSIBLE FLOODING FOR MUCH OF ARIZONA AND ADJACENT PARTS OF NEVADA AND NEW
MEXICO.
POSSIBLE FLOODING FOR EASTERN TEXAS, THE LOWER MISSISSIPPI AND TENNESSEE
VALLEYS AND ALABAMA.
DETAILED SUMMARY
FOR THURSDAY FEBRUARY 01 - MONDAY FEBRUARY 05:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY FEBRUARY 06 - MONDAY FEBRUARY 12: AFTER A BRIEF RESPITE, THE
WESTERN CONTIGUOUS U.S. (CONUS) IS FAVORED TO SEE A RESUMPTION IN STORM
ACTIVITY FROM THE PACIFIC. THESE WEATHER-RELATED HAZARDS INCLUDE HEAVY RAIN AT
LOWER ELEVATIONS, HEAVY MOUNTAIN SNOW, AND HIGH WINDS, IN ADDITION TO AREAS OF
POSSIBLE FLOODING, WITH THE SOUTHWESTERN QUARTER OF THE CONUS EXPECTED TO
RECEIVE THE BRUNT OF THE STORMINESS. A SLIGHT RISK (>=20%) OF HEAVY
PRECIPITATION (>= 1-INCH IN A 3-DAY PERIOD) IS FAVORED FOR NEARLY ALL OF
CALIFORNIA, SOUTHERN AND SOUTHWESTERN NEVADA, ARIZONA, AND WESTERN NEW MEXICO,
TUE-MON, FEB 6-12. MODERATE (>=40%) AND HIGH RISK (>=60%) AREAS ARE EMBEDDED
WITHIN THE HIGHLIGHTED SLIGHT RISK AREA, AND VALID FOR VARIOUS PORTIONS OF
WEEK-2. THESE AREAS ARE BASED LARGELY ON THE PROBABILISTIC EXTREMES TOOL (PET)
FOR PRECIPITATION, AND IN ADDITION TO THE CRITERIA NOTED ABOVE, PRECIPITATION
VALUES ARE EXPECTED TO REACH OR EXCEED THE 85TH PERCENTILE OF THE HISTORICAL
PRECIPITATION DISTRIBUTION. FROM CALIFORNIA EASTWARD ACROSS THE FOUR CORNERS
STATES, AT HIGHER ELEVATIONS, THERE IS A SLIGHT RISK OF HEAVY SNOW HIGHLIGHTED
FROM TUE-MON, FEB 6-12. THE GEFS SNOW WATER EQUIVALENT (SWE) PET TOOL AND
GEFS/ECMWF ENSEMBLES GENERALLY SUPPORT THIS BROAD HIGHLIGHTED SNOW AREA, WITH
AT LEAST A 20% CHANCE OF SWE VALUES REACHING OR EXCEEDING THE 85TH HISTORICAL
PERCENTILE, AND SNOWFALL AMOUNTS OF AT LEAST 6 INCHES. MODERATE AND HIGH RISK
AREAS FOR HEAVY SNOW ARE EMBEDDED WITHIN THE LARGE SLIGHT SHAPE, AND ARE VALID
FOR VARIOUS PORTIONS OF WEEK-2. FARTHER NORTH, THERE IS A SLIGHT RISK OF HEAVY
SNOW FOR PORTIONS OF THE NORTHERN INTERMOUNTAIN REGION, NORTHERN ROCKIES AND
NORTHERN HIGH PLAINS, TUE-THU, FEB 6-8, IN ADVANCE OF A BROAD MID-LEVEL TROUGH
PREDICTED TO MOVE INTO THE WESTERN CONUS. TIED TO THE AMPLIFIED MID-LEVEL
TROUGHING FAVORED, A SLIGHT RISK IS POSTED FROM CALIFORNIA EASTWARD ACROSS THE
FOUR CORNERS STATES, THE CENTRAL AND SOUTHERN PLAINS, AND INTO THE MIDDLE AND
LOWER MISSISSIPPI VALLEY, TUE-MON, FEB 6-12. THE ECMWF ENSEMBLE MEAN (ECENS)
PET WIND TOOL AND VARIOUS MODEL PRESSURE GRADIENT FIELDS, IN ADDITION TO THE
PREDICTED BROAD MID-LEVEL TROUGH OVER THE WEST, GENERALLY SUPPORT A SLIGHT RISK
OF HIGH WINDS (AT LEAST 20-25 MPH) OVER THIS WIDESPREAD REGION. THE ECENS PET
ALSO DEPICTS WINDS AT OR ABOVE THE 85TH PERCENTILE, WHILE THE GEFS PET WIND
TOOL IS MUCH LESS BULLISH IN COMPARISON. AT THE BASE OF THE TROUGH, AN EMBEDDED
MODERATE RISK ARE FOR HIGH WINDS IS ALSO POSTED FOR SOUTHERN CALIFORNIA, FAR
SOUTHERN PORTIONS OF NEVADA AND UTAH, ARIZONA, AND PARTS OF THE SOUTHERN
ROCKIES, TUE-FRI, FEB 6-9.
OVER THE CENTRAL AND EASTERN CONUS, SIGNIFICANTLY FEWER HAZARDS ARE POSTED. AS
NOTED EARLIER, THE SLIGHT RISK OF HIGH WINDS EXTENDS EASTWARD FROM CALIFORNIA
AND THE FOUR CORNERS REGION INTO THE MIDDLE AND LOWER MISSISSIPPI VALLEY. GEFS
AND ECENS DYNAMICAL GUIDANCE PREDICTS LEE CYCLOGENESIS ACROSS THE HIGH PLAINS
OF COLORADO DURING EARLY-MID WEEK-2. AS THIS DEVELOPING STORM SYSTEM TRACKS
NORTHEASTWARD TOWARDS THE GREAT LAKES, THERE IS A SLIGHT RISK FOR HEAVY SNOW ON
THE NORTHERN AND WESTERN SIDES OF THIS SYSTEM, FROM THE CENTRAL HIGH PLAINS TO
THE UPPER MISSISSIPPI VALLEY, THU-SUN, FEB 8-11. THE SOMEWHAT BROAD VALID
PERIOD OF THIS EVENT IS A REFLECTION OF THE UNCERTAINTY IN THE TIMING DETAILS
BETWEEN THE GEFS AND ECENS MODELS. DESPITE LARGE PREDICTED SURFACE TEMPERATURE
ANOMALIES DURING WEEK-2 ACROSS THE NORTH-CENTRAL CONUS, THE FAVORED
PRECIPITATION TYPE IS STILL THOUGHT TO BE SNOW RATHER THAN RAIN, BASED ON
TEMPERATURE TOOLS AT THIS LEAD. HOWEVER, FARTHER SOUTH, A SLIGHT RISK OF HEAVY
PRECIPITATION (RAIN) IS FAVORED OVER EASTERN TEXAS, THE LOWER MISSISSIPPI
VALLEY, TENNESSEE VALLEY, AND PART OF THE SOUTHEAST, THU-MON, FEB 8-12. THE
GEFS AND ECENS PRECIPITATION PETS COME INTO GOOD AGREEMENT LATER IN WEEK-2 ON
AT LEAST 1-INCH OF RAIN OVER A 3-DAY PERIOD ACROSS THE HIGHLIGHTED REGION.
NO TEMPERATURE, PRECIPITATION, OR WIND HAZARDS ARE INDICATED OVER ALASKA OR
HAWAII DURING THIS WEEK-2 HAZARDS OUTLOOK.
FORECASTER: ANTHONY ARTUSA
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