193
FXUS21 KWNC 241806
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JULY 24 2026
SYNOPSIS: STRONG MID-LEVEL HIGH PRESSURE IS FORECAST TO BRING A PROLONGED HEAT
WAVE TO THE WEST THROUGH THE BEGINNING OF AUGUST. ANTECEDENT DRYNESS ALONG WITH
THE LIKELIHOOD OF ABOVE-NORMAL TEMPERATURES AND BELOW-NORMAL PRECIPITATION
DURING THE NEXT TWO WEEKS SUPPORTS AN INCREASED RISK FOR THE RAPID ONSET OF
DROUGHT TO PARTS OF THE GREAT PLAINS AND CORN BELT. A MOISTURE SURGE ASSOCIATED
WITH A TROPICAL CYCLONE TRACKING NORTHWEST ACROSS THE EAST PACIFIC ALONG WITH
THE ONGOING/PREDICTED HEAT WAVE FAVORS A RENEWAL OF AN ENHANCED MONSOON DURING
EARLY AUGUST.
HAZARDS
HIGH RISK OF EXTREME HEAT FOR PORTIONS OF THE SOUTHWEST, GREAT BASIN, AND
CALIFORNIA, SAT-SUN, AUG 1-2.
MODERATE RISK OF EXTREME HEAT FOR MUCH OF THE SOUTHERN PLAINS, SOUTHWEST, GREAT
BASIN, AND CALIFORNIA, SAT-TUE, AUG 1-4.
SLIGHT RISK OF EXTREME HEAT FOR MOST OF THE WESTERN TWO-THIRDS OF THE CONUS AND
SOUTHEAST U.S., SAT-FRI, AUG 1-7.
SLIGHT RISK OF EXTREME HEAT FOR THE MIDWEST, WED-FRI, AUG 5-7.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE SOUTHEAST, SAT-SUN, AUG 1-2.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE DESERT SOUTHWEST, SUN-FRI,
AUG 2-7.
RAPID ONSET DROUGHT (ROD) POSSIBLE FOR PARTS OF THE GREAT PLAINS AND CORN BELT.
DETAILED SUMMARY
FOR MONDAY JULY 27 - FRIDAY JULY 31:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY AUGUST 01 - FRIDAY AUGUST 07: THE GEFS AND ECENS ARE IN GOOD
AGREEMENT AND REMAIN CONSISTENT IN SHOWING A HIGHLY AMPLIFIED 500-HPA RIDGE
PEAKING IN STRENGTH ON AUGUST 1ST WHEN IT BECOMES CENTERED OVER THE WESTERN
CONTIGUOUS U.S. (CONUS). MULIT-MODEL ENSEMBLE MEAN SOLUTIONS HAVE TRENDED
STRONGER WITH THIS RIDGE AND THE ECENS HAS 500-HPA HEIGHTS CLOSE TO 600 DM OVER
SOUTHERN NEVADA. THIS ANOMALOUS MID-LEVEL RIDGE CONTINUES TO SUPPORT A MODERATE
TO HIGH RISK OF EXTREME HEAT THROUGHOUT A LARGE AREA OF THE WESTERN CONUS. ON
AUGUST 1, THE NATIONAL BLEND OF MODELS INDICATES NEAR OR RECORD DAILY HIGHS FOR
PARTS OF ARIZONA, CALIFORNIA, AND NEVADA INCLUDING 102 DEG F AT RENO. A HIGH
RISK OF EXTREME HEAT, VALID AUGUST 1-2, IS POSTED FOR THE DESERT SOUTHWEST,
GREAT BASIN, AND CALIFORNIA, WHERE THE GEFS AND ECENS PROBABILISTIC TOOLS
(PETS) DEPICT MAXIMUM TEMPERATURES HAVING MORE THAN A 60% CHANCE OF EXCEEDING
THE 85TH PERCENTILE. MAXIMUM TEMPERATURES MAY EXCEED 115 DEG F IN THE DESERT
SOUTHWEST, WHILE THE CENTRAL VALLEY OF CALIFORNIA HEATS UP TO NEAR 105 DEG F. A
MODERATE RISK (40-60% CHANCE) OF EXTREME HEAT WAS EXTENDED THROUGH AUGUST 4TH
BASED ON THE PETS AND UNCALIBRATED GEFS AND ECENS TEMPERATURE ANOMALIES. THE
MODERATE RISK INCLUDES MUCH OF OKLAHOMA AND TEXAS WHERE HEAT INDEX VALUES COULD
REACH 110DEG F. TO THE EAST OF THE MISSISSIPPI RIVER, SPREAD AMONG THE GEFS AND
ECENS HAS DECREASED TODAY WITH A CONSENSUS TOWARDS A LESS AMPLIFIED 500-HPA
TROUGH OVER THE EASTERN CONUS. LATE IN WEEK-2 (AUGUST 5-7), MODEL GUIDANCE
INCLUDING THE PETS AND UNCALIBRATED ECMWF HEAT INDEX TOOL INDICATE THAT
ANOMALOUS HEAT MAY DEVELOP OVER THE MIDDLE MISSISSIPPI AND OHIO VALLEYS.
THEREFORE, A SLIGHT RISK OF EXTREME HEAT WAS INTRODUCED TO THESE AREAS,
BEGINNING ON AUGUST 5.
ACCORDING TO THE U.S. DROUGHT MONITOR VALID JULY 21, ABNORMAL DRYNESS (D0) AND
MODERATE DROUGHT (D1) EXPANDED THIS PAST WEEK ACROSS THE DAKOTAS WHERE RAPID
ONSET DROUGHT (ROD) IS WELL UNDERWAY. INCREASING 30-DAY PRECIPITATION DEFICITS,
HIGH EVAPOTRANSPIRATION RATES, AND THE INCREASED CHANCE OF ABOVE-NORMAL
TEMPERATURES AND BELOW-NORMAL PRECIPITATION DURING THE NEXT TWO WEEKS SUPPORT
AN ENHANCED RISK OF ROD ACROSS EVEN MORE OF THE GREAT PLAINS AND CORN BELT.
TROPICAL DEPRESSION 7-E FORMED IN THE EAST PACIFIC ON JULY 24. THE NATIONAL
HURRICANE CENTER FORECASTS IT TO BECOME A MAJOR HURRICANE AS IT TRACKS
NORTHWESTWARD. THE DETERMINISTIC GFS AND ECMWF MODELS AND THEIR ENSEMBLE
MEMBERS ARE TIGHTLY CLUSTERED WITH THIS TROPICAL CYCLONE TRACKING
NORTHWESTWARD, FAVORING A MOISTURE SURGE NORTH FROM THE GULF OF CALIFORNIA INTO
THE DESERT SOUTHWEST. AS THE WESTERN CONUS RIDGE AXIS SHIFTS NORTHWARD, THERE
WOULD BE AN INCREASING CHANCE OF AN ENHANCED MONSOON. BEGINNING ON AUG 2, A
SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED FOR THE DESERT SOUTHWEST WHERE THE
PETS GENERALLY DEPICT 3-DAY PRECIPITATION AMOUNTS EXCEEDING THE 85TH PERCENTILE
AND 0.5 INCH.
A FRONT IS EXPECTED TO BECOME STATIONARY FROM THE COASTAL CAROLINAS SOUTHWEST
TO THE FLORIDA PANHANDLE LATER NEXT WEEK. THROUGH AUGUST 2, THIS FRONT MAY
ENHANCE CONVECTION AND THE ECMWF PET SUPPORTS MAINTAINING A SLIGHT RISK OF
HEAVY PRECIPITATION FOR PARTS OF THE SOUTHEAST.
FORECASTER: BRAD PUGH
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