580
FXUS21 KWNC 151833
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 15 2026
SYNOPSIS: PERSISTENT ABOVE-NORMAL MID-LEVEL PRESSURE OVER THE WESTERN AND
SOUTHERN CONTIGUOUS U.S. (CONUS) FAVOR UNSEASONABLY WARM TEMPERATURES ACROSS
THE WEST AND ALONG THE GULF COAST, POTENTIALLY RESULTING IN EXTREME HEAT FOR
MANY LOCATIONS. A NEARLY STATIONARY AREA OF MID-LEVEL LOW PRESSURE OVER THE
GREAT LAKES IS FAVORED TO PRODUCE SEVERAL ROUNDS OF PRECIPITATION ACROSS THE
CENTRAL AND EASTERN CONUS, SOME OF WHICH COULD REACH HAZARDOUS CRITERIA.
HAZARDS
SLIGHT RISK OF EXTREME HEAT FOR FLORIDA AND ADJACENT REGIONS, TUE-MON, JUN
23-29.
SLIGHT RISK OF EXTREME HEAT FOR MUCH OF TEXAS, THE DESERT SOUTHWEST, AND THE
CENTRAL VALLEY, TUE-MON, JUN 23-29.
SLIGHT RISK OF EXTREME HEAT FOR THE INTERIOR NORTHWEST, TUE-MON, JUN 23-29.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE MIDDLE MISSISSIPPI, TENNESSEE, AND
LOWER OHIO VALLEYS AS WELL AS EASTERN PORTIONS OF THE SOUTHERN AND CENTRAL
PLAINS, TUE-WED, JUN 23-24.
DETAILED SUMMARY
FOR THURSDAY JUNE 18 - MONDAY JUNE 22:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY JUNE 23 - MONDAY JUNE 29: MULTIPLE MODEL ENSEMBLES CONTINUE TO
DEPICT A MOSTLY STATIONARY PATTERN ACROSS NORTH AMERICA DURING THE WEEK-2
PERIOD, WITH RIDGING OVER THE WESTERN CONUS AND TROUGHING OVER THE GREAT LAKES.
THIS PATTERN IS LIKELY TO RESULT IN UNSEASONABLY WARM TEMPERATURES ACROSS THE
WEST AND BRING POTENTIALLY EXTREME HEAT ALONG THE U.S.-MEXICO BORDER, AS WELL
AS MOST OF TEXAS AND THE CENTRAL VALLEY OF CALIFORNIA. THE PROBABILISTIC
EXTREMES TOOLS (PETS) FROM MULTIPLE ENSEMBLES INDICATE AT LEAST A 20% CHANCE OF
MAXIMUM TEMPERATURES EXCEEDING 100F ALONG THE RIO GRANDE AND IN THE CENTRAL
VALLEY OF CALIFORNIA, AND 110F FOR THE MOJAVE DESERT. TEMPERATURES ARE NOT
EXPECTED TO GET QUITE AS HIGH FOR CENTRAL TEXAS BUT VERY HIGH DEWPOINTS ARE
LIKELY, THE RESULT OF ROBUST INFLOW OF GULF MOISTURE THROUGHOUT THE FORECAST
PERIOD. THEREFORE A SLIGHT RISK OF EXTREME HEAT IS POSTED FOR THESE REGIONS,
VALID FOR ALL OF WEEK-2 (JUN 23-29). FURTHER NORTH THE PETS INDICATE AT LEAST A
20% CHANCE OF MAXIMUM TEMPERATURES TO EXCEED 95F FOR INTERIOR WASHINGTON AND
OREGON, AS WELL AS THE LOWER SNAKE RIVER VALLEY. WHILE HUMIDITY IS NOT LIKELY
TO BE MUCH OF A FACTOR, THIS IS WELL ABOVE THE 85TH CLIMATOLOGICAL PERCENTILE
AND WITHIN HEAT CRITERIA FOR THE REGION, THEREFORE A SLIGHT RISK OF EXTREME
HEAT IS ISSUED FOR THIS REGION, ALSO FOR ALL OF WEEK-2.
ENHANCED SUBTROPICAL RIDGING OVER THE WESTERN ATLANTIC AND GREATER ANTILLES IS
INDICATED BY MULTIPLE ENSEMBLES, FAVORING ABOVE-NORMAL TEMPERATURES FOR
FLORIDA. LIKE THE OTHER SYNOPTIC FEATURES HIGHLIGHTED, MODELS FAVOR THIS
ENHANCED RIDING TO REMAIN IN PLACE THROUGHOUT THE WEEK, RESULTING IN HIGHER
TEMPERATURES. WHILE MAXIMUM ACTUAL TEMPERATURES ARE NOT THAT LARGE, VERY HIGH
HUMIDITY HAS THE POTENTIAL TO PUSH APPARENT TEMPERATURES INTO HAZARDOUS
CRITERIA. ADDITIONALLY, RECORD TO NEAR-RECORD HIGH MINIMUM TEMPERATURES ARE
INDICATED BY THE NATIONAL BLEND OF MODELS, BRINGING VERY LITTLE RELIEF FROM
HEAT EFFECTS DURING OVERNIGHT HOURS. GIVEN ALL THIS, A SLIGHT RISK OF EXTREME
HEAT IS POSTED FOR ALL OF FLORIDA AND ADJACENT AREAS, ONCE AGAIN VALID FOR THE
WHOLE WEEK-2 FORECAST PERIOD.
MEANWHILE, PERSISTENT TROUGHING OVER THE GREAT LAKES IS FAVORED TO DEVELOP ONE
OR MORE FRONTAL BOUNDARIES AND PUSH AREAS OF RAIN ACROSS THE CENTRAL AND
EASTERN CONUS. MODEL SPREAD IS QUITE HIGH REGARDING THE EXTENT, TIMING, AND
DURATION OF RESULTANT PRECIPITATION, HOWEVER THE MIDDLE MISSISSIPPI AND LOWER
OHIO VALLEYS ARE WHERE MODELS SHOW THE MOST AGREEMENT. MULTIPLE PETS INDICATE
THE POTENTIAL FOR 3-DAY RAINFALL TOTALS TO EXCEED THE 85TH PERCENTILE AND AT
LEAST 1 INCH EARLY IN WEEK-2, WITH UNCALIBRATED DAILY PROBABILITIES OF
PRECIPITATION FROM THE GEFS AND ECENS TARGETING THE FIRST TWO DAYS OF THE
FORECAST PERIOD IN PARTICULAR. THIS INCREASED CONCURRENCE AMONG THE MODELS,
ALONG WITH SYNOPTIC PATTERN RECOGNITION WARRANTS A CONTINUATION OF A SLIGHT
RISK OF HEAVY PRECIPITATION FOR THE MIDDLE MISSISSIPPI, TENNESSEE, AND LOWER
OHIO VALLEYS AS WELL AS EASTERN PORTIONS OF THE SOUTHERN AND CENTRAL PLAINS,
COVERING THE PERIOD JUN 23-24.
FORECASTER: DANNY BARANDIARAN
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