600
FXUS21 KWNC 051908
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MAY 05 2025
SYNOPSIS: EARLY IN WEEK-2, A SLOW-MOVING LOW PRESSURE SYSTEM IS FORECAST TO
MOVE OFF THE SOUTHEAST COAST, WITH PRECIPITATION LIKELY TO LINGER FOR SEVERAL
DAYS OVER THE REGION. AFTER A RELATIVELY BRIEF PERIOD OF DRIER WEATHER ACROSS
THE SOUTH-CENTRAL STATES, HEAVY RAIN AND THUNDERSTORMS ARE PREDICTED TO RETURN
TO THE REGION DURING THE MIDDLE AND LATTER PORTIONS OF THE FORECAST PERIOD.
MID-LEVEL HIGH PRESSURE FAVORS ABOVE-NORMAL TEMPERATURES ACROSS THE NORTHERN
AND CENTRAL GREAT PLAINS ALONG WITH THE CORN BELT EARLY IN WEEK-2.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE SOUTH-CENTRAL CONUS,
FRI-MON, MAY 16-19.
DETAILED SUMMARY
FOR THURSDAY MAY 08 - MONDAY MAY 12:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY MAY 13 - MONDAY MAY 19: DURING WEEK-2, MULTI-MODEL ENSEMBLE
GUIDANCE PREDICTS A MID-LEVEL RIDGE AND POSITIVE HEIGHT ANOMALIES OVER THE
NORTHEASTERN QUARTER OF THE CONTIGUOUS U.S. (CONUS), AND MID-LEVEL TROUGHS NEAR
THE SOUTHEAST COAST AND OVER THE INTERIOR WEST. EARLY IN THE PERIOD, A
SLOW-MOVING LOW PRESSURE SYSTEM IS FORECAST TO MOVE OFF THE SOUTHEAST COAST.
PRECIPITATION IS LIKELY TO LINGER ACROSS PORTIONS OF THE CAROLINAS AND GEORGIA,
AND MUCH OF THE FLORIDA PENINSULA FOR THE FIRST TWO DAYS OF THE PERIOD.
ACCORDING TO UNCALIBRATED ECENS PRECIPITATION FORECASTS, AND GEFS AND ECENS
PRECIPITATION PROBABILISTIC EXTREMES TOOLS (PETS), UP TO AN INCH OF RAIN MAY
FALL. PRECIPITATION DEFICITS OVER THE PAST 30 DAYS RANGE FROM 1-3 INCHES OVER
MUCH OF THIS AREA, WITH THE HIGHER DEFICITS OVER FLORIDA WHICH IS NEARING THE
END OF ITS CLIMATOLOGICAL DRY SEASON. THEREFORE, THIS RAIN IS CONSIDERED TO BE
BENEFICIAL RATHER THAN HAZARDOUS.
A MID-LEVEL TROUGH MOVING ACROSS THE INTERIOR WEST IS PREDICTED TO SPREAD
PRECIPITATION ACROSS THE NORTHERN GREAT BASIN, NORTHERN ROCKIES, AND EVENTUALLY
THE NORTHERN HIGH PLAINS, AS THE MID-LEVEL TROUGH PROMOTES SURFACE CYCLOGENESIS
EAST OF THE NORTHERN ROCKIES. ABOUT 0.50-0.75 INCH OF PRECIPITATION IS EXPECTED
ACROSS THE REGION, WHICH FALLS SHORT OF HAZARDOUS THRESHOLDS. HEAVIER
PRECIPITATION (1-INCH OR GREATER IN A 3-DAY PERIOD, AND AMOUNTS GREATER THAN
THE 85TH CLIMATOLOGICAL PERCENTILE) ARE FORECAST OVER CENTRAL AND SOUTH-CENTRAL
PORTIONS OF THE NATION. THIS IS ASSOCIATED WITH STORM ACTIVITY IN ADVANCE OF
THE WESTERN MID-LEVEL TROUGH AND INCREASED LOW-LEVEL GULF MOISTURE. AFTER A
BRIEF RESPITE FROM OCCASIONAL HEAVY RAIN, THUNDERSTORMS, AND FLOODING, THE
SOUTH-CENTRAL STATES ARE EXPECTED TO SEE A RENEWAL OF ENHANCED STORM ACTIVITY.
A SLIGHT RISK AREA OF HEAVY PRECIPITATION IS POSTED FOR SOUTH-CENTRAL SECTIONS
OF THE GREAT PLAINS AND ADJACENT PARTS OF THE MISSISSIPPI VALLEY, MAY 16-19.
SLOW-MOVING OR TRAINING THUNDERSTORMS ARE CAPABLE OF PRODUCING LOCALLY HEAVIER
AMOUNTS OF RAIN, WITH AN ASSOCIATED FLASH FLOOD RISK.
AN AMPLIFIED 500-HPA RIDGE INITIALLY CENTERED OVER THE UPPER GREAT LAKES REGION
STRONGLY FAVORS ABOVE-NORMAL TEMPERATURES ACROSS THE NORTH-CENTRAL CONUS.
DESPITE THE IMPRESSIVE-LOOKING SIGNAL IN THE ECENS TEMPERATURE PET, PREDICTING
A 40 PERCENT CHANCE OF TEMPERATURES EXCEEDING 90 DEG F, NO TEMPERATURE HAZARDS
ARE POSTED FOR THIS REGION. HAZARDS CRITERIA AT THIS TIME OF YEAR REQUIRE AIR
TEMPERATURES OF ABOUT 95 DEGREES AND HEAT INDEX VALUES NEAR 100 DEG F.
THE GEFS, ECENS, AND CMCE FEATURE A WEAK 500-HPA TROUGH PERSISTING OVER THE
BERING SEA AND PORTIONS OF WESTERN ALASKA THROUGH MOST OF WEEK-2, AND A WEAK
RIDGE OVER EASTERN ALASKA. THOUGH ONSHORE FLOW IS FAVORED ACROSS SOUTHERN
ALASKA, WITH SURFACE LOW PRESSURE NEAR THE ALEUTIANS, NO HAZARDOUS
PRECIPITATION IS POSTED. AS TEMPERATURES WARM THIS MONTH, RIVER ICE BREAKUP
WILL CONTINUE WHICH COULD LEAD TO ICE JAMS AND FLOODING.
FORECASTER: ANTHONY ARTUSA
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