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FXUS21 KWNC 301919
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST JANUARY 30 2024
SYNOPSIS: A WET START TO FEBRUARY IS FORECAST ACROSS CALIFORNIA AND THE
SOUTHWEST WITH AN INCREASED RISK OF HEAVY PRECIPITATION, HEAVY SNOW, AND HIGH
WINDS LINGERING THROUGH FEBRUARY 7 AND 8. HOWEVER, DURING THE SECOND WEEK OF
FEBRUARY, MORE TRANQUIL WEATHER IS EXPECTED THROUGHOUT THE WEST. AS MID-LEVEL
LOW PRESSURE SHIFTS EASTWARD TO THE INTERIOR WEST, SURFACE LOW DEVELOPMENT IS
FORECAST ACROSS SOUTHEASTERN COLORADO. ALONG THE NORTHEAST TRACK OF THIS LOW
PRESSURE SYSTEM, THERE COULD BE A SWATH OF SNOWFALL FROM THE CENTRAL GREAT
PLAINS TO THE UPPER MIDWEST. A WETTER-THAN-NORMAL PATTERN IS FAVORED ACROSS
SATURATED AREAS OF THE LOWER MISSISSIPPI VALLEY. SOUTHERN ALASKA IS ALSO LIKELY
TO EXPERIENCE PERIODS OF ENHANCED PRECIPITATION DURING EARLY TO MID-FEBRUARY.
HAZARDS
HIGH RISK OF HEAVY PRECIPITATION FOR PARTS OF SOUTHERN CALIFORNIA AND ARIZONA,
WED, FEB 7.
HIGH RISK OF HEAVY SNOW FOR PARTS OF ARIZONA, WED, FEB 7.
MODERATE RISK OF HEAVY PRECIPITATION FOR PARTS OF CALIFORNIA AND THE SOUTHWEST,
WED-THU, FEB 7-8.
MODERATE RISK OF HEAVY SNOW FOR PARTS OF THE SOUTHWEST, WED-THU, FEB 7-8.
SLIGHT RISK OF HEAVY PRECIPITATION FOR MUCH OF CALIFORNIA AND THE SOUTHWEST,
WED-FRI, FEB 7-9.
SLIGHT RISK OF HEAVY SNOW FOR THE HIGHER ELEVATIONS OF CALIFORNIA, THE GREAT
BASIN, SOUTHWEST, AND ROCKIES, WED-FRI, FEB 7-9.
SLIGHT RISK OF HEAVY SNOW FOR THE CENTRAL GREAT PLAINS AND UPPER MIDWEST,
THU-TUE, FEB 8-13.
MODERATE RISK OF HIGH WINDS FOR SOUTHERN CALIFORNIA, THE SOUTHWEST, AND CENTRAL
TO SOUTHERN HIGH PLAINS, WED-FRI, FEB 7-9.
SLIGHT RISK OF HIGH WINDS FOR SOUTHERN CALIFORNIA, THE SOUTHWEST, AND CENTRAL
TO SOUTHERN GREAT PLAINS, WED-SAT, FEB 7-10.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE LOWER MISSISSIPPI VALLEY AND PARTS
OF THE SOUTHEAST, FRI-TUE, FEB 9-13.
SLIGHT RISK OF HEAVY PRECIPITATION FOR KODIAK ISLAND, THE KENAI PENINSULA, AND
SOUTHEASTERN ALASKA, FRI-TUE, FEB 9-13.
FLOODING POSSIBLE FOR EASTERN TEXAS AND THE LOWER MISSISSIPPI VALLEY ALONG WITH
PARTS OF THE SOUTHWEST AND CALIFORNIA.
DETAILED SUMMARY
FOR FRIDAY FEBRUARY 02 - TUESDAY FEBRUARY 06:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR WEDNESDAY FEBRUARY 07 - TUESDAY FEBRUARY 13: THE 0Z GEFS, ECMWF, AND
CANADIAN ENSEMBLE MEANS DEPICT A VIGOROUS 500-HPA SHORTWAVE TROUGH TRACKING
EASTWARD ACROSS SOUTHERN CALIFORNIA AND THE SOUTHWEST FROM FEBRUARY 7 TO 9.
BASED ON A CONSENSUS BETWEEN THE GEFS AND ECMWF PROBABILISTIC EXTREMES TOOLS
(PETS) ALONG WITH UNCALIBRATED 24-HOUR AMOUNTS FROM THE GEFS, ECMWF, AND
CANADIAN MODELS, A HIGH RISK OF HEAVY PRECIPITATION (LIKELY MORE THAN 1 INCH,
LIQUID EQUIVALENT) IS POSTED FOR PARTS OF SOUTHERN CALIFORNIA AND ARIZONA. A
BROADER MODERATE AND SLIGHT RISK OF HEAVY PRECIPITATION IS SUPPORTED THROUGH
FEBRUARY 8 AND 9, RESPECTIVELY. BEYOND THAT TIME, THE SIGNAL FOR HEAVY
PRECIPITATION DIMINISHES. THE POTENT MID-LEVEL TROUGH SUPPORTS A HIGH (FEBRUARY
7) AND MODERATE (FEBRUARY 7 AND 8) RISK OF HEAVY SNOW AT THE HIGHER ELEVATIONS
OF SOUTHERN CALIFORNIA AND THE SOUTHWEST. A SLIGHT RISK OF HEAVY SNOW (FEBRUARY
7 TO 10) EXTENDS NORTHWARD TO INCLUDE MORE OF THE GREAT BASIN AND CENTRAL
ROCKIES AS A MORE FULL LATITUDE TROUGH BECOMES ESTABLISHED EARLY IN WEEK-2.
BASED ON PATTERN RECOGNITION WITH THE MID-LEVEL TROUGH CROSSING THE FOUR
CORNERS REGION AND LEESIDE SURFACE CYCLOGENESIS, A MODERATE RISK OF HIGH WINDS
(FEBRUARY 7-9) IS POSTED FOR PARTS OF CALIFORNIA, THE SOUTHWEST, AND CENTRAL TO
SOUTHERN HIGH PLAINS. A SLIGHT RISK COVERING A BROADER AREA OF THE WEST AND
CENTRAL TO SOUTHERN GREAT PLAINS IS VALID THROUGH FEBRUARY 10.
AN AMPLIFIED 500-HPA TROUGH OVER THE WEST IS LIKELY TO RESULT IN SURFACE LOW
DEVELOPMENT ACROSS SOUTHEASTERN COLORADO DURING THE SECOND WEEK OF FEBRUARY.
HOWEVER, MODEL SOLUTIONS VARY ON THE TIMING AND ALSO SUGGEST THAT THERE COULD
BE A COUPLE OF WAVES OF LOW PRESSURE. A SWATH OF SNOW, POTENTIALLY HEAVY, MAY
ACCOMPANY A LOW PRESSURE SYSTEM TRACKING NORTHEASTWARD ACROSS THE CENTRAL GREAT
PLAINS AND UPPER MIDWEST. DUE TO UNCERTAINTY ON TIMING, A SLIGHT RISK OF HEAVY
SNOW IS VALID FROM FEBRUARY 8 TO 13. A MITIGATING FACTOR ON HEAVY SNOWFALL WILL
BE THE ANTECEDENT WARM AIRMASS OVER THE CENTRAL U.S. DURING EARLY FEBRUARY.
MINOR TO MODERATE RIVER FLOODING MAY LINGER ACROSS EASTERN TEXAS AND THE LOWER
MISSISSIPPI VALLEY INTO WEEK-2. DUE TO HEAVY PRECIPITATION DURING LATE WEEK-1
AND INTO THE BEGINNING OF WEEK-2, A FLOODING POSSIBLE HAZARD IS POSTED FOR
PARTS OF CALIFORNIA AND THE SOUTHWEST. BOTH OF THESE FLOODING HAZARDS WILL BE
REASSESSED ON THE NEXT HAZARDS OUTLOOK.
THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS REMAIN CONSISTENT AND IN GOOD
AGREEMENT WITH AN AMPLIFIED 500-HPA TROUGH AND MEAN SURFACE LOW OVER THE
ALEUTIANS. ENHANCED ONSHORE IS LIKELY TO AFFECT SOUTHERN ALASKA AND BASED ON
THE GEFS AND ECMWF PETS, A SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED FOR
KODIAK ISLAND, THE KENAI PENINSULA, AND SOUTHEASTERN ALASKA FROM FEBRUARY 9-13.
FORECASTER: BRAD PUGH
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