077
FXUS21 KWNC 141808
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 14 2026
SYNOPSIS: MID-LEVEL HIGH PRESSURE IS EXPECTED TO INCREASE CHANCES FOR EXTREME
HEAT FROM THE CENTRAL GULF COAST THROUGH FLORIDA AND THE SOUTH ATLANTIC COAST
INTO THE MIDDLE OF THE PERIOD. THEN, AS CONDITIONS IN THE SOUTHEAST EASE,
MID-LEVEL HIGH PRESSURE IS EXPECTED TO BUILD FARTHER WEST IN THE SECOND HALF OF
WEEK-2, BRINGING THE THREAT OF EXTREME HEAT TO THE SOUTH-CENTRAL STATES, THE
DESERT SOUTHWEST, AND THE CALIFORNIA CENTRAL VALLEY. A SURFACE FRONT ALONG THE
SOUTHERN EDGE OF UNSEASONABLY COOL AIR IS PREDICTED EARLY WEEK-2 FROM THE
EAST-CENTRAL GREAT PLAINS THROUGH MUCH OF THE MIDDLE MISSISSIPPI, TENNESSEE,
AND OHIO VALLEYS, ENHANCING CHANCES FOR HEAVY PRECIPITATION THERE.
HAZARDS
SLIGHT RISK OF EXTREME HEAT ALONG THE CENTRAL GULF AND SOUTH ATLANTIC COASTS,
AND THE ENTIRE FLORIDA PENINSULA, MON-FRI, JUN 22-26.
SLIGHT RISK OF EXTREME HEAT FOR MUCH OF THE VICINITY OF THE SOUTHERN PLAINS AND
LOUISIANA, THU-SUN, JUN 25-28.
SLIGHT RISK OF EXTREME HEAT ACROSS THE DESERT SOUTHWEST AND CENTRAL VALLEY OF
CALIFORNIA, THU-SUN, JUN 25-28.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE EAST-CENTRAL PLAINS, MIDDLE
MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS AND ADJACENT AREAS, MON-TUE, JUN 22-23.
DETAILED SUMMARY
FOR WEDNESDAY JUNE 17 - SUNDAY JUNE 21:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR MONDAY JUNE 22 - SUNDAY JUNE 28: SUBTROPICAL MID-LEVEL RIDGING IS EXPECTED
TO EXTEND INTO THE FLORIDA PENINSULA AND ADJACENT AREAS OF THE CENTRAL GULF AND
SOUTHERN ATLANTIC COASTS THROUGH THE MIDDLE OF WEEK-2, INCREASING THE ODDS FOR
EXTREME HEAT IN THOSE AREAS. BIAS-CORRECTED GEFS AND ECENS HEAT INDEX GUIDANCE
FOR WEEK-2 DEPICTS VALUES PEAKING NEAR 105 DEG F, AND THE NATIONAL BLEND OF
MODELS (NBM) PREDICTS NEAR-RECORD OR RECORD HIGH NIGHTTIME MINIMUM TEMPERATURES
OF 76-80 DEG F ACROSS MUCH OF THE FLORIDA PENINSULA AND A FEW NEARBY LOCATIONS.
SOME LOCATIONS ON THE FLORIDA KEYS MAY NOT DROP BELOW 85 DEG F ON ONE OR MORE
NIGHTS. THE PROBABILISTIC EXTREMES TOOLS (PETS) FROM THE EUROPEAN ENSEMBLE
(ECENS), CANADIAN ENSEMBLE (CMCE), AND GEFS DEPICT THE BEST CHANCES FOR HIGH
TEMPERATURES ABOVE THE 85TH CLIMATOLOGICAL PERCENTILE ACROSS THE FLORIDA
PENINSULA (WITH THE ECENS DEPICTING 30 PERCENT CHANCES OR GREATER). THE SLIGHT
RISK OF EXTREME HEAT CONTINUES THROUGH JUNE 26TH WHEN MOST TOOLS SHOW THE
SUBTROPICAL MID-LEVEL RIDGE FLATTENING ACROSS THE SOUTHEAST AND EMERGING
FARTHER WEST.
DURING THE MIDDLE AND LATTER PARTS OF WEEK-2, MID-LEVEL SUBTROPICAL RIDGING IS
EXPECTED TO EMERGE OVER THE CENTRAL AND INTERIOR WESTERN CONUS, BRINGING AN
INCREASED RISK OF EXTREME HEAT TO MUCH OF THE SOUTH-CENTRAL CONUS ALONG WITH
MUCH OF THE DESERT SOUTHWEST AND CALIFORNIA'S CENTRAL VALLEY. INTERNAL
SKILL-WEIGHTED GUIDANCE BLENDING ECENS AND GEFS OUTPUT SHOWS 40 TO 60 PERCENT
CHANCES FOR HEAT INDICES OVER 105 DEG F ACROSS MOST OF LOUISIANA, EASTERN
TEXAS, THE CENTRAL TIER OF OKLAHOMA, AND THE LOWER RIO GRANDE VALLEY. THIS
APPEARS LARGELY DRIVEN BY UNUSUALLY HIGH HUMIDITY, AS THE PETS DEPICT ACTUAL
AIR TEMPERATURES REMAINING NEAR OR BELOW 100 DEG F WITH LOW CHANCES OF REACHING
THE 85TH CLIMATOLOGICAL PERCENTILE. HOWEVER, UNCALIBRATED TEMPERATURES FROM THE
ECENS AND GEFS SHOW ONE OR TWO INCURSIONS OF UNSEASONABLY COOL AIR MOVING INTO
THE SOUTH-CENTRAL PLAINS AND LOWER MISSISSIPPI VALLEY, RESULTING IN SIGNIFICANT
UNCERTAINTY IN THE TEMPERATURE OUTLOOK. A SLIGHT RISK OF EXTREME HEAT IS
THEREFORE DESIGNATED FOR THE SOUTHERN HIGH PLAINS, TEXAS, AND LOUISIANA, JUNE
25-28. CONSIDERABLY ABOVE NORMAL TEMPERATURES COVER MOST OF THE INTERIOR WEST,
INCLUDING THE ROCKIES, INTERMOUNTAIN WEST, AND NORTHWEST DURING THE LAST HALF
OF WEEK-2, BUT TEMPERATURES AND HEAT INDICES ARE EXPECTED TO REMAIN BELOW
HAZARDS THRESHOLDS. THE PETS AND INTERNAL HEAT INDEX GUIDANCE FROM THE ECENS
AND GEFS DEPICT LOW CHANCES FOR TEMPERATURES OR HEAT INDICES TO TOP 100 DEG F
IN THESE AREAS.
THE BUILDING MID-LEVEL SUBTROPICAL RIDGE ALSO INCREASES THE CHANCES FOR EXTREME
HEAT IN THE DESERT SOUTHWEST AND THE CENTRAL VALLEY OF CALIFORNIA DURING THE
LATTER HALF OF WEEK-2. THE ECENS AND GEFS PETS SHOW A 20 TO 30 PERCENT CHANCE
OF TEMPERATURES REACHING 110 DEG F IN THE DESERT SOUTHWEST ON SOME DAYS DURING
THE SECOND HALF OF WEEK-2, AND COMPARABLE CHANCES FOR HIGHS TOPPING OUT OVER
100 DEG F IN THE CALIFORNIA CENTRAL VALLEY. THE SAME TOOLS SHOW 20 TO 30
PERCENT CHANCES FOR TEMPERATURES EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE.
A FRONTAL BOUNDARY (SEPARATING THE HEAT IN THE SOUTHEAST FROM UNSEASONABLY COOL
AIR FARTHER NORTH) IS EXPECTED TO BE DRAPED FROM THE EAST-CENTRAL GREAT PLAINS
EASTWARD THROUGH MOST OF THE MIDDLE MISSISSIPPI, TENNESSEE, AND OHIO VALLEYS
EARLY WEEK-2. THIS IS EXPECTED TO DRIVE ABUNDANT PRECIPITATION AND ENHANCED
THUNDERSTORM ACTIVITY. THE PETS INDICATE AT LEAST A 20% CHANCE OF 3-DAY
PRECIPITATION EXCEEDING THE 85TH CLIMATOLOGICAL PERCENTILE. UNCALIBRATED ECENS
OUTPUT DEPICTS A 30 TO 60 PERCENT CHANCE FOR PRECIPITATION TOTALS TO EXCEED AN
INCH DURING THE FIRST FEW DAYS OF THE PERIOD THROUGHOUT THE SLIGHT RISK AREA.
TOWARD THE MIDDLE OF WEEK-2, MID-LEVEL TROUGHING AND UNUSUALLY COOL SURFACE AIR
IS EXPECTED TO MODERATE AND RETRACT NORTHEASTWARD, WEAKENING THE FRONTAL
BOUNDARY AND BRINGING AN END TO THE HEAVY PRECIPITATION THREAT. GIVEN THIS, A
SLIGHT RISK OF HEAVY PRECIPITATION REMAINS POSTED FOR PORTIONS OF THE
EAST-CENTRAL PLAINS, MIDDLE MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS VALID JUN
22-23.
FORECASTER: ANTHONY ARTUSA
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