012
FXUS21 KWNC 141810
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MARCH 14 2025
SYNOPSIS: ENHANCED ONSHORE FLOW IS FORECAST TO BRING AN INCREASED RISK OF HEAVY
PRECIPITATION, HEAVY MOUNTAIN SNOW, AND HIGH WINDS TO THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA. AS MID-LEVEL LOW PRESSURE PROGRESSES INLAND OVER THE WEST,
HEAVY SNOW MAY OVERSPREAD THE NORTHERN ROCKIES AND WASATCH MOUNTAINS WITH GUSTY
WINDS EXPECTED ACROSS THE INTERIOR WEST AND HIGH PLAINS. SURFACE LOW PRESSURE
DEVELOPMENT IS PROBABLE SOMEWHERE ACROSS THE GREAT PLAINS AT THE BEGINNING OF
WEEK-2 LEADING TO INCREASED CHANCES FOR HEAVY PRECIPITATION FROM THE OHIO
VALLEY SOUTH TO THE GULF COAST. DUE TO DIFFERING MODEL SOLUTIONS ON THE
EVOLVING LONGWAVE PATTERN DURING WEEK-2, FORECAST UNCERTAINTY IS RELATIVELY
HIGH. ANOMALOUS POSITIVE MID-LEVEL HEIGHTS ARE PREDICTED OVER THE SOUTHWESTERN
U.S. DURING WEEK-2, SUPPORTING INCREASED LIKELIHOOD FOR MUCH ABOVE NORMAL
TEMPERATURES FOR PARTS OF SOUTHERN TEXAS. ANTICIPATED AND ANTECEDENT DRY
CONDITIONS COMBINED WITH INCREASED POTENTIAL FOR ANOMALOUSLY WARM TEMPERATURES
AND GUSTY WINDS LEADS TO AN INCREASED RISK OF RAPID ONSET DROUGHT ACROSS PARTS
OF THE SOUTHERN PLAINS AND WILDFIRE DANGER FROM NEW MEXICO EAST TO TEXAS.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR COASTAL AREAS OF THE PACIFIC NORTHWEST
AND NORTHERN CALIFORNIA, SAT-MON, MAR 22-24.
SLIGHT RISK OF HEAVY SNOW FOR THE CASCADES, NORTHERN SIERRA NEVADA MOUNTAINS,
NORTHERN ROCKIES, AND WASATCH MOUNTAINS, SAT-MON, MAR 22-24.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE WEST AND HIGH PLAINS, SAT-SUN,
MAR 22-23.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE OHIO, TENNESSEE, AND
LOWER MISSISSIPPI VALLEYS, AND SOUTHEAST U.S., SUN-MON, MAR 23-24.
SLIGHT RISK OF MUCH ABOVE NORMAL TEMPERATURES FOR SOUTHERN TEXAS, SAT-FRI, MAR
22-28.
RAPID ONSET DROUGHT RISK ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS.
DETAILED SUMMARY
FOR MONDAY MARCH 17 - FRIDAY MARCH 21:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY MARCH 22 - FRIDAY MARCH 28: MULTIPLE MODEL ENSEMBLE MEANS DEPICT A
MID-LEVEL TROUGH TRAVERSING THE WESTERN CONUS AT THE BEGINNING OF THE PERIOD,
ALTHOUGH THERE CONTINUES TO BE SIGNIFICANT DIFFERENCES REGARDING THE DETAILS OF
THIS FEATURE. THE 0Z GEFS ENSEMBLE MEAN FAVORS MID-LEVEL TROUGHING OVER THE
WEST COAST AT THE ONSET OF WEEK-2, WHEREAS THE ECENS AND CANADIAN COUNTERPARTS
INDICATE THE TROUGH CENTERED FURTHER INLAND OVER THE ROCKIES. SUBSEQUENT
DIVERGENCE AMONG MODELS REGARDING THE EVOLUTION OF THIS TROUGH AS IT MOVES
EASTWARD LEADS TO UNCERTAINTY IN THE RESULTANT HAZARDS.
A SLIGHT RISK OF HEAVY PRECIPITATION REMAINS DESIGNATED FOR MAR 22-24 FOR
COASTAL AREAS OF NORTHERN CALIFORNIA, OREGON, AND WASHINGTON, WHERE THE
CALIBRATED ECENS (GEFS) PROBABILISTIC EXTREMES TOOL (PET) INDICATES AT LEAST A
30% (20%) CHANCE OF 3-DAY ACCUMULATED TOTALS EXCEEDING THE 85TH PERCENTILE AND
ONE INCH. UNCALIBRATED ECENS AND GEFS ENSEMBLES SHOW AT LEAST A 40% CHANCE OF
SOME AREAS RECEIVING GREATER THAN 2 INCHES OF PRECIPITATION DURING THE RISK
PERIOD. IN ADDITION TO THE INCREASED RISK OF HEAVY PRECIPITATION, A SLIGHT RISK
OF HEAVY SNOW IS POSTED FOR THE CASCADES, NORTHERN SIERRA NEVADA MOUNTAINS,
NORTHERN ROCKIES, AND WASATCH MOUNTAINS BASED ON THE 500-HPA TROUGH SHIFTING
INLAND AND THE GEFS PET INDICATING A GREATER THAN 20 PERCENT CHANCE OF 3-DAY
SNOW WATER EQUIVALENT (LIQUID EQUIVALENT) TOTALS EXCEEDING 1 INCH. ALTHOUGH THE
GEFS AND ECENS DIFFER ON THE AMPLITUDE OF A 500-HPA TROUGH PROGRESSING EASTWARD
FROM THE NORTHEASTERN PACIFIC TO THE WESTERN CONUS EARLY IN WEEK-2, THE
PREDICTED SURFACE AND 500-HPA LONGWAVE PATTERN SUPPORT A SLIGHT RISK OF HIGH
WINDS FOR A BROAD AREA FROM THE WEST COAST EAST ACROSS THE ROCKIES TO THE HIGH
PLAINS FROM MARCH 22-23.
AS THE MID-LEVEL TROUGH SHIFTS EAST TO THE ROCKIES, LEESIDE CYCLOGENESIS IS
PREDICTED ACROSS THE CENTRAL HIGH PLAINS. ENSEMBLE SPREAD CONTINUES TO BE
SIGNIFICANT REGARDING THE LOCATION AND STRENGTH OF A DEVELOPING LOW PRESSURE
SYSTEM, TRANSLATING TO UNCERTAINTY IN ASSOCIATED HAZARDS. ENHANCED GULF INFLOW
IS ANTICIPATED TO PROVIDE ADEQUATE LOW-LEVEL MOISTURE AND INSTABILITY THAT
COULD INCREASE CHANCES FOR THUNDERSTORMS AND LOCALLY HEAVY PRECIPITATION. THE
ECENS AND GEFS PETS INDICATE AT LEAST A 20% CHANCE OF 3-DAY TOTALS (MAR 22-24)
EXCEEDING THE 85TH PERCENTILE AND ONE INCH ACROSS THE PORTIONS OF THE OHIO,
TENNESSEE, AND LOWER MISSISSIPPI VALLEYS, AND SOUTHEAST U.S. A SLIGHT RISK OF
HEAVY PRECIPITATION IS DESIGNATED FOR THESE AREAS MAR 23-24, WHERE THE TIMING
IS BASED ON DAILY ENSEMBLE GUIDANCE OF WHEN THE HEAVIEST PRECIPITATION IS
LIKELY TO OCCUR. 28-DAY AVERAGE STREAMFLOWS ARE RUNNING AT OR ABOVE THE 90TH
PERCENTILE THROUGHOUT MUCH OF KENTUCKY AND NORTHWESTERN TENNESSEE WHICH MAKES
THOSE AREAS VULNERABLE TO FLOODING. A POSSIBLE FLOODING HAZARD IS NOT POSTED AT
THIS TIME DUE TO UNCERTAINTY REGARDING WHERE THE HEAVIEST PRECIPITATION WOULD
OCCUR DURING WEEK-2.
POSITIVE ANOMALOUS 500-HPA HEIGHT DEPARTURES ARE PREDICTED DURING WEEK-2 OVER
THE SOUTHWESTERN CONUS. THIS PATTERN FAVORS INCREASED CHANCES FOR ABOVE-NORMAL
TEMPERATURES ACROSS THE REGION, AND A SLIGHT RISK OF MUCH ABOVE NORMAL
TEMPERATURES ACROSS SOUTHERN TEXAS. THE PETS INDICATE AT LEAST A 20% CHANCE OF
MAXIMUM TEMPERATURES EXCEEDING THE 85TH PERCENTILE AND 90 DEG F.
ACCORDING TO THE U.S. DROUGHT MONITOR VALID ON MARCH 11TH, EASTERN NEW MEXICO
AND THE TEXAS PANHANDLE ARE DESIGNATED WITH EITHER ABNORMAL DRYNESS (D0) OR
MODERATE DROUGHT (D1). A RAPID ONSET DROUGHT RISK IS MAINTAINED FOR PORTIONS OF
THESE AREAS BASED ON: TOPSOIL MOISTURE BELOW THE 30TH PERCENTILE ALONG WITH
ANTICIPATED LITTLE TO NO PRECIPITATION, ANOMALOUSLY WARM TEMPERATURES, AND
PERIODS OF ENHANCED SURFACE WINDS. DUE TO THE ANTECEDENT DRYNESS, ANY PERIODS
WITH ENHANCED WINDS ARE LIKELY TO RESULT IN AN INCREASED RISK OF WILDFIRE
DANGER FROM NEW MEXICO EAST TO TEXAS.
NEAR-NORMAL 500 HPA HEIGHT DEPARTURES ARE FORECAST FOR THE MEAN WEEK-2 PERIOD
ACROSS MUCH OF MAINLAND ALASKA, TRANSLATING TO NO ANTICIPATED HAZARDS
DESIGNATED FOR THE STATE.
FORECASTER: MELISSA OU
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