479
FXUS21 KWNC 161821
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JULY 16 2026
SYNOPSIS: AN AREA OF MID-LEVEL HIGH PRESSURE OVER THE SOUTH-CENTRAL CONTIGUOUS
U.S. (CONUS) IS FORECAST BRINGING ELEVATED CHANCES OF EXTREME HEAT TO THE
REGION. FURTHER NORTH, ABOVE NORMAL TEMPERATURES BRING A CONTINUED RISK OF
RAPID ONSET DROUGHT TO PARTS OF THE NORTHERN PLAINS. ACROSS THE INTERIOR WEST,
A SLIGHT CHANCE OF HEAVY PRECIPITATION ASSOCIATED WITH MONSOON MOISTURE IS
POSSIBLE. FINALLY, A LINGERING BOUNDARY ACROSS THE SOUTHEASTERN CONUS BRINGS
CHANCES FOR HEAVY PRECIPITATION TO PARTS OF THE SOUTHEAST AND MID-ATLANTIC.
HAZARDS
MODERATE RISK OF EXTREME HEAT FOR PARTS OF THE SOUTHERN PLAINS AND THE LOWER
MISSISSIPPI VALLEY, FRI-MON, JUL 24-27.
SLIGHT RISK OF EXTREME HEAT FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS, LOWER
MISSISSIPPI AND TENNESSEE VALLEYS, SOUTHEAST U.S., AND SOUTHWEST, FRI-THU, JUL
24-30.
SLIGHT RISK OF EXTREME HEAT FOR INTERIOR WASHINGTON, AND ADJACENT PARTS OF
IDAHO AND OREGON, FRI, JUL 24.
SLIGHT RISK OF HEAVY PRECIPITATION FOR MUCH OF THE SOUTHWEST, CENTRAL GREAT
BASIN, AND CENTRAL ROCKIES, FRI-SUN, JUL 24-26.
SLIGHT RISK OF HEAVY PRECIPITATION FOR PARTS OF THE LOWER MID-ATLANTIC AND
SOUTHEAST, FRI-SUN, JUL 24-26.
RAPID ONSET DROUGHT (ROD) POSSIBLE FOR PORTIONS OF THE DAKOTAS.
DETAILED SUMMARY
FOR SUNDAY JULY 19 - THURSDAY JULY 23:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY JULY 24 - THURSDAY JULY 30: MULTIPLE MODEL ENSEMBLES DEPICT
ANOMALOUS MID-LEVEL RIDGING PERSISTING OVER THE WESTERN AND CENTRAL CONUS
THROUGH MUCH OF WEEK-2, WITH A CLOSED 594-DM CONTOUR REMAINING NEAR THE FOUR
CORNERS. THERE IS INCREASED SUPPORT FOR A PERIOD OF SUBTROPICAL RIDGING TO
BUILD INTO THE SOUTH-CENTRAL CONUS AT THE END OF WEEK-1 AND INTO WEEK-2. THIS
PARTICULARLY STANDS OUT IN THE NORMALIZED 500-HPA HEIGHT ANOMALIES WHERE 1 TO 2
STANDARD DEVIATION ANOMALIES ARE FORECAST AT THE CLIMATOLOGICAL PEAK OF SUMMER.
GENERALLY, SOUTHERLY FLOW OFF THE GULF OF AMERICA IS FAVORED TO BOOST DEWPOINTS
EAST OF THE ROCKIES, RESULTING IN POTENTIALLY HAZARDOUS HEAT INDEX VALUES IN
PARTS OF THE CENTRAL AND SOUTHERN PLAINS AND GULF COAST. FURTHER WEST,
TEMPERATURE RISES FAVORED EARLY IN WEEK-2 INCREASES CHANCES FOR EXTREME HEAT TO
DEVELOP ACROSS PARTS OF THE SOUTHWEST.
THE POTENTIAL FOR EXTREME HEAT CONTINUES TO BE SUPPORTED BY A VARIETY OF
FORECAST TOOLS WITH ELEVATED FORECAST CONFIDENCE OVER PARTS OF THE SOUTHERN
PLAINS AND LOWER MISSISSIPPI VALLEY. THE GEFS-ECWMF COMBINED EXTREME HEAT TOOL
SHOWS WIDESPREAD 20 TO 40% CHANCES OF EITHER MAXIMUM TEMPERATURES OR HEAT INDEX
VALUES TO EXCEED THE 90TH PERCENTILE AT SOME POINT DURING THE WEEK-2 PERIOD FOR
MOST OF THE CONUS EXCEPT ALONG THE NORTHERN TIER. ADDITIONALLY, PROBABILITIES
EXCEED 40% AND AS HIGH AS 60% FOR THE SAME THRESHOLD ACROSS PARTS OF TEXAS AND
THE LOWER MISSISSIPPI VALLEY. GIVEN ALL THIS, A MODERATE RISK OF EXTREME HEAT
IS POSTED FOR PARTS OF THE SOUTHERN PLAINS AND THE LOWER MISSISSIPPI VALLEY
COVERING JUL 24-27. THE LENGTHEND VALID PERIOD IN THE UPDATED OUTLOOK IS THE
RESULT OF BETTER AGREEMENT FOR MID-LEVEL RIDGING TO PERSIST DURING WEEK-2
ACROSS THE REGION. A BROADER SLIGHT RISK OF EXTREME HEAT REMAINS POSTED FOR
MUCH OF CENTRAL AND SOUTHERN PLAINS, MIDDLE AND LOWER MISSISSIPPI VALLEY,
TENNESSEE VALLEY, AND SOUTHEAST FOR ALL OF WEEK-2. THIS SLIGHT RISK IS ALSO
EXPANDED INTO THE SOUTHWEST IN TODAY’S FORECAST.
A SLIGHT RISK OF EXTREME HEAT REMAINS POSTED FOR INTERIOR WASHINGTON FOR JUL
24, CONSISTENT WITH INCREASED SIGNAL FROM THE EXTREME HEAT TOOLS. GUIDANCE FROM
THE UNCALIBRATED AND PET TOOLS SHOW ELEVATED SIGNALS ACROSS THE PACIFIC
NORTHWEST AT THE END OF WEEK-1 AND INTO WEEK-2.
ABOVE NORMAL TEMPERATURES ARE LIKELY TO PERSIST ACROSS THE NORTHERN PLAINS,
ALTHOUGH THESE TEMPERATURES ARE LESS LIKELY TO REACH HAZARDOUS THRESHOLDS.
HOWEVER, THE COMBINATION OF ANOMALOUS WARMTH AND DRYNESS DURING WEEK-1,
COMBINED WITH NEAR TO SLIGHTLY ABOVE NORMAL PRECIPITATION FAVORED DURING
WEEK-2, AND ANTECEDENT DRYNESS SUPPORTS AN ENHANCED RISK OF RAPID ONSET DROUGHT
(ROD) ACROSS PORTIONS OF THE NORTHERN PLAINS.
WITH MID-LEVEL RIDGING MORE STRONGLY DEVELOPING ACROSS THE FOUR CORNERS BY THE
EARLY TO MIDDLE PART OF WEEK-2, THERE ARE DECREASING SIGNALS FOR MONSOONAL
MOISTURE MOVING INTO THE INTERIOR WEST. PETS HAVE BEEN SLOWLY SHUNTING THE
MOISTURE SIGNAL FURTHER WEST AND REDUCING THE SIGNAL AS WELL. FURTHERMORE, THE
DAILY UNCALIBRATED PRECIPITATION GUIDANCE IS DISTINCTLY REDUCED RELATIVE TO
PRIOR FORECASTS. THEREFORE, THE MODERATE RISKS OF HEAVY PRECIPITATION ALONG
WITH THE FLOODING POSSIBLE SHAPES ARE DISCONTINUED TODAY. A SLIGHT RISK REMAINS
POSTED FOR THE FIRST THREE DAYS OF THE PERIOD. THERE COULD STILL BE MORE
SCATTERED THUNDERSTORMS ACROSS THE REGION AND SOME SUPPORT REMAINS IN THE
GUIDANCE. MONSOONAL MOISTURE CAN ALSO PRODUCE DRY LIGHTNING, RESULTING IN
INCREASED WILDFIRE RISK WHERE PRECIPITATION DOES NOT FALL.
A SLIGHT RISK OF HEAVY PRECIPITATION IS FORECAST FOR PARTS OF THE SOUTHEAST
ATLANTIC STATES AND SOUTHERN MID-ATLANTIC FOR JUL 24-26. MODELS CONTINUE TO
SUPPORT A LINGERING FRONTAL BOUNDARY BRINGING ELEVATED CHANCES FOR HEAVY
PRECIPITATION TO THE REGION EARLY IN WEEK-2. BOTH THE PETS AND UNCALIBRATED
GUIDANCE BRING AT LEAST 20% CHANCES FOR THREE DAY PRECIPITATION AMOUNTS TO
EXCEED THE 85TH CLIMATOLOGICAL PERCENTILE AND 1 INCH ACROSS THE HIGHLIGHTED
REGION.
FORECASTER: RYAN BOLT
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