961
FXUS21 KWNC 211832
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MARCH 21 2025
SYNOPSIS: AN ACTIVE AND PROGRESSIVE WEATHER PATTERN IS FAVORED TO BRING A
VARIETY OF POTENTIALLY HAZARDOUS WEATHER TO MANY PARTS OF THE CONTIGUOUS U.S.
(CONUS) DURING THE WEEK-2 PERIOD. MID-LEVEL LOW PRESSURE OVER THE NORTH PACIFIC
AND WEST COAST IS ANTICIPATED TO BRING PERIODS OF ENHANCED MOISTURE TO THE
WEST. THERE ARE GREATER SIGNALS IN THE MODELS REGARDING THE POTENTIAL FOR
HAZARDOUS HEAVY PRECIPITATION AND HIGH ELEVATION SNOW FOR THE WEST COAST,
RESULTING IN THE ADDITION OF MODERATE RISK DESIGNATIONS FOR THESE HAZARDS IN
THE UPDATED OUTLOOK. SLIGHT RISKS FOR HIGH WINDS CONTINUE FOR PARTS OF THE WEST
IN ADDITION TO HEAVY SNOW ACROSS THE ROCKIES. MEANWHILE, A SERIES OF SURFACE
LOWS ARE PREDICTED TO FORM OVER THE CENTRAL CONUS AND MOVE NORTHEASTWARD AT THE
BEGINNING OF THE PERIOD. THERE CONTINUES TO BE SIGNIFICANT UNCERTAINTY
REGARDING THE DETAILS OF THESE FEATURES RESULTING IN SLIGHT RISKS OF HEAVY
PRECIPITATION, HEAVY SNOW, AND HIGH WINDS ACROSS AREAS EAST OF THE ROCKIES FROM
THE BEGINNING TO MIDDLE OF WEEK-2.
HAZARDS
MODERATE RISK OF EPISODIC HEAVY PRECIPITATION ACROSS PARTS OF SOUTHWESTERN
OREGON AND NORTHERN AND CENTRAL CALIFORNIA, MON-WED, MAR 31-APR 2.
MODERATE RISK OF EPISODIC HEAVY SNOW ACROSS THE SOUTHERN CASCADES, KLAMATH, AND
SIERRA NEVADA MOUNTAINS, MON-WED, MAR 31-APR 2.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE LOWER MISSISSIPPI, OHIO,
AND TENNESSEE VALLEYS, SOUTHERN APPALACHIANS, AND SOUTHEAST U.S., SAT-SUN, MAR
29-30.
SLIGHT RISK OF EPISODIC HEAVY PRECIPITATION ACROSS PARTS OF THE WEST COAST,
MON-FRI, MAR 31-APR 4.
SLIGHT RISK OF EPISODIC HEAVY SNOW ACROSS THE CASCADES, KLAMATH, AND SIERRA
NEVADA MOUNTAINS, MON-FRI, MAR 31-APR 4.
SLIGHT RISK OF HEAVY SNOW ACROSS PARTS OF THE UPPER MIDWEST, GREAT LAKES, AND
NORTHEAST, SAT-SUN, MAR 29-30.
SLIGHT RISK OF PERIODS OF HEAVY SNOW FOR MUCH OF THE NORTHERN AND CENTRAL
ROCKIES, MON-FRI, MAR 31-APR 4.
SLIGHT RISK OF PERIODS OF HIGH WINDS ACROSS PARTS OF THE WEST COAST, SAT-FRI,
MAR 29-APR 4.
SLIGHT RISK OF PERIODS OF HIGH WINDS ACROSS PARTS OF THE FOUR CORNERS REGION,
CENTRAL AND SOUTHERN PLAINS, AND COLORADO, SAT-WED, MAR 29-APR 2.
SLIGHT RISK OF EPISODIC HIGH WINDS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN
PLAINS, MIDDLE AND UPPER MISSISSIPPI, AND OHIO VALLEYS, GREAT LAKES REGION,
MID-ATLANTIC, AND NORTHEAST, SAT-WED, MAR 29-APR 2.
RISK OF RAPID ONSET DROUGHT FOR PORTIONS OF THE SOUTHERN PLAINS.
DETAILED SUMMARY
FOR MONDAY MARCH 24 - FRIDAY MARCH 28:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY MARCH 29 - FRIDAY APRIL 04: GUIDANCE AND TOOLS FROM MULTIPLE
MODELS ARE IN GOOD AGREEMENT INDICATING A MORE FAVORABLE PATTERN FOR ENHANCED
ONSHORE FLOW TO THE WEST COAST, INCREASING THE CHANCES FOR HEAVY PRECIPITATION,
HIGH ELEVATION SNOW, AND HIGH WINDS FOR PARTS OF THE WEST COAST, COMPARED TO
YESTERDAY. THERE IS MORE UNCERTAINTY FARTHER EAST REGARDING THE INTENSITY AND
EVOLUTION OF A SERIES OF SURFACE LOWS ANTICIPATED TO FORM OVER THE CENTRAL
CONUS AND MOVING NORTHEASTWARD AT THE BEGINNING OF WEEK-2.
MULTIPLE ENSEMBLE MEANS SHOW A MORE FAVORABLE SETUP OF MID-LEVEL TROUGHING OVER
THE NORTH PACIFIC AND WEST COAST CONDUCIVE TO ENHANCED ONSHORE FLOW TO THE WEST
COMPARED TO YESTERDAY. THIS TRANSLATES TO INCREASED SIGNALS OF HEAVY
PRECIPITATION AND HIGH ELEVATION SNOW IN MODEL GUIDANCE AND TOOLS. THE GEFS
INTEGRATED VAPOR TRANSPORT (IVT) TOOL HAS SIGNIFICANTLY RAMPED UP ITS
PROBABILITIES OF VALUES EXCEEDING 250 KG/M S TO BE MORE SIMILAR TO THE ECENS,
RESULTING IN GREATER AGREEMENT AND HIGHER CONFIDENCE IN THE TOOLS REGARDING THE
POTENTIAL FOR HEAVY PRECIPITATION AND SNOW ACROSS THE WEST COAST. THEREFORE, A
MODERATE RISK OF HEAVY PRECIPITATION IS DESIGNATED FOR PARTS OF SOUTHWESTERN
OREGON AND NORTHERN AND CENTRAL CALIFORNIA, MAR 31-APR 2, AND A MODERATE RISK
OF HEAVY SNOW IS POSTED FOR THE SOUTHERN CASCADES, KLAMATH, AND SIERRA NEVADA
MOUNTAINS FOR THE SAME PERIOD. THE POTENTIAL FOR THESE IMPACTS INCREASES BY DAY
10 (MAR 31) AS THE MID-LEVEL TROUGH OVER THE NORTH PACIFIC SHIFTS CLOSER TO THE
WEST COAST. THE ECENS (GEFS) PROBABILISTIC EXTREMES TOOL (PET) INDICATES AT
LEAST A 50% (30%) CHANCE OF 3-DAY LIQUID EQUIVALENT ACCUMULATED TOTALS
EXCEEDING THE 85TH PERCENTILE CLIMATOLOGICALLY AND ONE INCH (2 INCHES LOCALLY)
ACROSS MUCH OF THE MODERATE RISK AREA FOR PRECIPITATION. BROADER AREAS ACROSS
THE WEST COAST ARE HIGHLIGHTED WITH A SLIGHT RISK OF EPISODIC HEAVY
PRECIPITATION AND HEAVY SNOW, MAR 31-APR 4. LOCALIZED FLOODING IS POSSIBLE
ESPECIALLY ACROSS PORTIONS OF SOUTHWESTERN OREGON WHERE 28-DAY AVERAGE
STREAMFLOWS ARE GREATER THAN THE 90TH PERCENTILE. A SLIGHT RISK OF HIGH WINDS
IS DESIGNATED FOR PARTS OF THE WEST COAST, MAR 29-APR 4, WHERE PETS INDICATE AT
LEAST A 20% CHANCE OF WINDS WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 35
MPH (NEAR THE COAST), FURTHER SUPPORTED BY THE ANTICIPATED SYNOPTIC PATTERN AND
RECENT DETERMINISTIC MODEL SOLUTIONS.
A SERIES OF SURFACE LOWS AND ACCOMPANYING FRONTS ARE PREDICTED TO FORM OVER THE
INTERIOR WEST DURING THE PERIOD. THESE FEATURES SUPPORT A SLIGHT RISK OF
PERIODIC HEAVY SNOW FOR MUCH OF THE NORTHERN AND CENTRAL ROCKIES MAR 31-APR 4,
AND A SLIGHT RISK OF EPISODIC HIGH WINDS ACROSS PARTS OF THE FOUR CORNERS
REGION, CENTRAL AND SOUTHERN PLAINS, AND COLORADO, MAR 29-APR 2. THE
UNCALIBRATED ECENS ENSEMBLES INDICATE INCREASED CHANCES FOR 3-DAY SNOWFALL
TOTALS EXCEEDING 4 INCHES (6 INCHES LOCALLY), WHILE THE PETS INDICATE AT LEAST
A 20% CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 20 MPH ACROSS THE
HIGHLIGHTED RISK AREAS.
FARTHER EAST, ONE OR MORE SURFACE LOWS AND ASSOCIATED FRONTS ARE FORECAST TO
FORM OVER THE CENTRAL PLAINS AND TRACK NORTHEASTWARD FROM THE BEGINNING TO
MIDDLE OF WEEK-2, INCREASING THE LIKELIHOOD OF HAZARDOUS PRECIPITATION AND WIND
SPEEDS TO AREAS EAST OF THE ROCKIES. DUE TO CONTINUED UNCERTAINTY REGARDING THE
SPECIFICS OF THE SURFACE LOW INTENSITIES AND TRACKS, ONLY SLIGHT RISKS REMAIN
HIGHLIGHTED OVER BROAD AREAS FOR BOTH HAZARDOUS PRECIPITATION AND SNOW. A
SLIGHT RISK OF HEAVY PRECIPITATION IS DESIGNATED FOR PARTS OF THE LOWER
MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS, SOUTHERN APPALACHIANS, AND SOUTHEAST
U.S., MAR 29-30, WHERE PETS SHOW AT LEAST A 20% CHANCE OF 3-DAY PRECIPITATION
EXCEEDING THE 85TH PERCENTILE AND ONE INCH OR WHERE UNCALIBRATED ENSEMBLE
GUIDANCE SHOWS INCREASED PROBABILITIES FOR HEAVY PRECIPITATION. A SLIGHT RISK
OF HEAVY SNOW IS SLIGHTLY DECREASED IN SPATIAL COVERAGE COMPARED TO YESTERDAY
BASED ON RECENT MODEL AND TOOL GUIDANCE, TO INCLUDE PARTS OF THE UPPER MIDWEST,
GREAT LAKES, AND NORTHEAST MAR 29-MAR 30. THESE AREAS ARE HIGHLIGHTED BASED ON
THE GEFS SNOW WATER EQUIVALENT (SWE) PET INDICATING AT LEAST A 20% CHANCE OF
3-DAY TOTALS EXCEEDING THE 85TH PERCENTILE AND WHERE UNCALIBRATED ENSEMBLE
GUIDANCE AND RECENT DETERMINISTIC MODEL SOLUTIONS SHOW ENHANCED SNOW SIGNALS. A
SLIGHT RISK OF EPISODIC HIGH WINDS IS DESIGNATED FOR PORTIONS OF THE CENTRAL
AND SOUTHERN PLAINS, MIDDLE AND UPPER MISSISSIPPI, AND OHIO VALLEYS, GREAT
LAKES REGION, MID-ATLANTIC, AND NORTHEAST, MAR 29-APR 2, ASSOCIATED WITH THESE
POTENTIAL SERIES OF STORMS.
ANOMALOUSLY WARM TEMPERATURES ARE LIKELY FOR PORTIONS OF WESTERN AND SOUTHERN
TEXAS. THESE TEMPERATURES COMBINED WITH BELOW-NORMAL PRECIPITATION AND ENHANCED
WIND SPEEDS INCREASES THE POTENTIAL FOR WILDFIRES THROUGHOUT THE WEEK-2 PERIOD,
ESPECIALLY ACROSS THE SOUTHERN PLAINS AND EASTERN FOUR CORNERS REGION. THESE
PREDICTED CONDITIONS IN ADDITION TO ANTECEDENT DRY CONDITIONS AND CURRENT
PRECIPITATION DEFICITS SUPPORT THE CONTINUED RISK OF RAPID ONSET DROUGHT (ROD)
FOR PORTIONS OF EASTERN NEW MEXICO AND NORTHERN TEXAS.
THE AFOREMENTIONED MID-LEVEL TROUGH OVER THE NORTH PACIFIC IS PREDICTED TO
SUPPORT PERSISTENT SURFACE LOW PRESSURE OVER THE GULF OF ALASKA, BUT IS NOT
ANTICIPATED TO BRING WIDESPREAD CONDITIONS THAT REACH HAZARDOUS CRITERIA.
FORECASTER: MELISSA OU
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