765
FXUS21 KWNC 221956
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JUNE 22 2026
SYNOPSIS: MID-LEVEL HIGH PRESSURE OVER THE SOUTHEASTERN CONUS BRINGS AN
INCREASED RISK OF EXTREME HEAT FROM THE FLORIDA PENINSULA NORTHWARD INTO THE
MID-ATLANTIC REGION THROUGHOUT WEEK-2. MID-LEVEL HIGH PRESSURE IS ALSO FAVORED
TO BUILD WESTWARD ACROSS MUCH OF THE EASTERN AND CENTRAL CONTIGUOUS U.S.
(CONUS), INCREASING THE RISK OF EXTREME HEAT ACROSS THOSE AREAS. MEANWHILE,
EARLY IN THE PERIOD, A SURFACE LOW OVER SOUTH-CENTRAL CANADA WITH ENHANCED
MOISTURE TRANSPORT FROM THE SOUTH SUPPORTS AN INCREASED RISK OF HEAVY
PRECIPITATION ACROSS PARTS OF THE MIDDLE AND UPPER MISSISSIPPI VALLEY, AND
PORTIONS OF THE WESTERN GREAT LAKES REGION.
HAZARDS
HIGH RISK OF EXTREME HEAT FOR PARTS OF THE MID-ATLANTIC REGION, TUE-THU, JUN
30-JUL 2.
MODERATE RISK OF EXTREME HEAT FOR THE SOUTHERN PLAINS, TUE-FRI, JUN 30-JUL 3.
MODERATE RISK OF EXTREME HEAT FOR THE MID-ATLANTIC REGION, TUE-SAT, JUN 30-JUL
4.
SLIGHT RISK OF EXTREME HEAT FOR MUCH OF THE GREAT PLAINS, LOWER AND MIDDLE
MISSISSIPPI, OHIO AND TENNESSEE VALLEYS, GULF COAST STATES, SOUTHEAST, AND
MID-ATLANTIC, TUE-MON, JUN 30-JUL 6.
SLIGHT RISK OF HEAVY PRECIPITATION FROM THE EASTERN DAKOTAS EASTWARD ACROSS THE
UPPER AND MIDDLE MISSISSIPPI VALLEY, AND WESTERN PORTIONS OF THE GREAT LAKES
REGION, TUE-THU, JUN 30-JUL 2.
DETAILED SUMMARY
FOR THURSDAY JUNE 25 - MONDAY JUNE 29:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR TUESDAY JUNE 30 - MONDAY JULY 06: EARLY IN WEEK-2, MID-LEVEL HEIGHT ANOMALY
FORECASTS FROM THE GLOBAL ENSEMBLE FORECAST SYSTEM (GEFS), EUROPEAN ENSEMBLE
(ECENS), AND CANADIAN ENSEMBLE (CMCE) FAVOR A RIDGE OVER THE EAST-CENTRAL
MID-LATITUDE PACIFIC, A TROUGH CENTERED NEAR THE WEST COAST, A RIDGE OVER MOST
OF THE REMAINDER OF THE CONUS, AND A WEAK TROUGH SITUATED OFF THE ATLANTIC
COAST. WELL TO THE NORTH, WEAK TROUGHS ARE PREDICTED NEAR THE WEST COAST OF
ALASKA AND OVER SOUTHEAST ALASKA. AT THE BEGINNING OF WEEK-2, A RESPECTABLE
TROUGH PREDICTED OVER THE NORTHERN ROCKIES AND NORTHERN PLAINS IS FORECAST TO
RAPIDLY WEAKEN, WITH THE MEAN TROUGH RELOADING BACK OVER THE PACIFIC NORTHWEST.
THE MID-LEVEL RIDGE OVER THE EAST IS EXPECTED TO SHIFT WESTWARD WITH ITS AXIS
REACHING THE GREAT PLAINS LATE IN THE FORECAST PERIOD. POSITIVE HEIGHT
ANOMALIES OF 60-120 METERS ARE FORECAST FROM THE NORTHERN ROCKIES TO THE UPPER
GREAT LAKES REGION, AND AS FAR SOUTH AS THE CENTRAL PLAINS. IN ADDITION, A
594-DM HEIGHT CONTOUR IS DEPICTED OVER THE FOUR CORNERS REGION LATER IN WEEK-2
(CMCE IS SHIFTED SLIGHTLY EAST COMPARED TO THE OTHER ENSEMBLE MEANS), WHICH IS
CONSISTENT WITH THE CLIMATOLOGICAL ONSET OF THE SOUTHWEST SUMMER MONSOON.
AN AMPLIFIED MID-LEVEL RIDGE OVER THE EASTERN CONUS IS PREDICTED TO SHIFT
WESTWARD WITH TIME, REACHING THE GREAT PLAINS LATE IN THE FORECAST PERIOD. A
SLIGHT RISK OF EXTREME HEAT IS POSTED FOR A LARGE PORTION OF THE EASTERN AND
CENTRAL CONUS DURING WEEK-2. FOR THE EASTERN SEABOARD, ACTUAL AIR TEMPERATURES
MAY EXCEED 95 DEGREES IN WASHINGTON, D.C., BALTIMORE, AND PHILADELPHIA, WITH 90
DEGREES OR HIGHER FORECAST IN NEW YORK CITY. IN ADDITION, HIGH HUMIDITY IS
EXPECTED TO ACCOMPANY THE HEAT, WITH DEW POINT TEMPERATURES REACHING THE UPPER
60'S AND LOW 70'S. HEAT INDEX VALUES MAY REACH OR SLIGHTLY EXCEED 105 DEG F FOR
AREAS AS FAR NORTH AS PHILADELPHIA. A MODERATE RISK OF EXTREME HEAT IS
DESIGNATED FROM SOUTHEASTERN PENNSYLVANIA AND SOUTHERN NEW JERSEY SOUTHWARD
THROUGH MOST OF NORTH CAROLINA, JUN 30-JUL 4. EMBEDDED WITHIN THIS MODERATE
RISK AREA IS A HIGH RISK FOR EXTREME HEAT FROM DELAWARE TO NORTHERN PORTIONS OF
NORTH CAROLINA, JUN 30-JUL 2. THESE RISK AREAS ARE BASED ON CONSIDERATION OF
UNCALIBRATED TEMPERATURE TOOLS FROM THE ENSEMBLE MEANS, CALIBRATED
PROBABILISTIC EXTREMES TOOL (PET) TEMPERATURE GUIDANCE, AND WEEK-2
BIAS-CORRECTED AND SKILL-WEIGHTED CALIBRATED AND UNCALIBRATED HEAT TOOLS. THERE
ARE TWO IMPORTANT CONSIDERATIONS DURING THIS FORECAST PERIOD. FIRST, THE
NATIONAL BLEND OF MODELS (NBM) PREDICTS NEAR-RECORD OR RECORD-BREAKING HIGH
MINIMUM TEMPERATURES OVERNIGHT, IN THE MID-UPPER 70S, OVER A WIDESPREAD PORTION
OF THE EAST, INCLUDING THE SOUTHEAST AS FAR NORTH AS VIRGINIA. THEREFORE,
NIGHTTIME RECOVERY AND RELIEF WILL BE VERY LIMITED. THE SECOND CONSIDERATION IS
THE NATION'S 250TH ANNIVERSARY THIS JULY 4TH, WITH LOTS OF OUTDOOR ACTIVITIES
PLANNED. STAYING HYDRATED AND LIMITING EXPOSURE TO VERY HOT, HUMID WEATHER IS
VERY IMPORTANT, ESPECIALLY FOR THE ELDERLY.
OTHER AREAS, SUCH AS THE OHIO VALLEY AND PORTIONS OF THE MIDWEST ARE PREDICTED
TO EXPERIENCE SIMILAR CONDITIONS, THOUGH FOR THE OHIO VALLEY TEMPERATURE
THRESHOLDS ARE ABOUT 5 DEGREES COOLER. THEREFORE, AIR TEMPERATURES OF AT LEAST
90 DEGREES, COMBINED WITH HEAT INDEX VALUES APPROACHING 100 DEG F, CAN BE
EXPECTED IN THIS REGION. THE EXTREME HEAT RISK EXPANDS INTO THE SOUTHERN
PLAINS, AND CENTRAL HIGH PLAINS, PERHAPS AS FAR NORTH AS WESTERN SOUTH DAKOTA.
TEMPERATURES OF AT LEAST 100 DEG F, AND HEAT INDEX VALUES OF ABOUT 105 DEG F
ARE GENERALLY FORECAST. FOR SOUTHERN OKLAHOMA AND ADJACENT NORTHERN TEXAS, THE
HEAT INDEX MAY REACH 110 DEG F, AS SHOWN BY THE WEEK-2, BIAS-CORRECTED HEAT
TOOL THAT USES THE GEFS AND ECENS. SOIL MOISTURE AND/OR WEEK-1 HEAVY
PRECIPITATION CONSIDERATIONS KEPT PARTS OF EASTERN KANSAS OUT OF THE SLIGHT
RISK AREA OF EXTREME HEAT. IN ADDITION, A MODERATE RISK OF EXTREME HEAT IS
DESIGNATED FOR PARTS OF THE SOUTHERN PLAINS, JUN 30-JUL 3, WHERE DRIER
CONDITIONS ARE EXPECTED.
THE PREDICTED PRESENCE OF AN UPSTREAM MID-LEVEL TROUGH OVER THE NORTHERN
ROCKIES AND NORTHERN PLAINS AND A SURFACE LOW OVER SOUTH-CENTRAL CANADA WITH
TRAILING FRONT FAVORS A SLIGHT RISK OF HEAVY PRECIPITATION EARLY IN THE PERIOD
(JUN 30-JUL 2) FROM THE EASTERN DAKOTAS EASTWARD ACROSS PORTIONS OF THE UPPER
AND MIDDLE MISSISSIPPI VALLEY, AND ADJACENT WESTERN GREAT LAKES REGION. THIS
DESIGNATED AREA IS CONSISTENT WITH WHERE THE PETS AND THE UNCALIBRATED TOOLS
FAVOR 1-INCH OR MORE OF PRECIPITATION, WITH THE PETS SIGNALS BEING MORE MUTED
COMPARED TO THE UNCALIBRATED GUIDANCE. ANOTHER CONSIDERATION IS THE ENHANCED
LIKELIHOOD OF MCS ACTIVITY IN THIS REGION, ESPECIALLY DURING THE SECOND HALF OF
THE PERIOD WHEN THE MID-LEVEL RIDGE IS FORECAST TO HAVE SHIFTED TO THE GREAT
PLAINS. AT THIS TIME OF YEAR, THUNDERSTORM CLUSTERS OFTEN FORM NEAR THE RIDGE
CREST AND TRAVEL SOUTHEASTWARD WITH TIME NEAR THE SOUTHERN EDGE OF THE
WESTERLIES. THIS PART OF THE COUNTRY TYPICALLY RECEIVES ABOUT 30-40 PERCENT OF
ITS ANNUAL PRECIPITATION DURING THE SUMMER, LARGELY FROM MCS ACTIVITY AND
PASSING FRONTS. THIS PRECIPITATION IS VERY BENEFICIAL TO AGRICULTURE. SCATTERED
AREAS OF FLOODING ARE POSSIBLE WHERE THERE ARE LOCALIZED HEAVIER RAINFALL
TOTALS, BUT CHANCES ARE NOT HIGH ENOUGH TO JUSTIFY A SPECIFIC AREA AT RISK OF
BROAD-SCALE FLOODING. ELSEWHERE, AN INCH OF PRECIPITATION IS INDICATED BY THE
PET GUIDANCE ACROSS THE FLORIDA PENINSULA, THOUGH IT IS PREDICTED TO FALL OVER
A 7-DAY PERIOD, NOT A 3-DAY PERIOD AS IS REQUIRED FOR HAZARDOUS DESIGNATION.
NO HAZARDS ARE POSTED OVER ALASKA, BUT THERE IS THE POTENTIAL FOR INCREASED
THUNDERSTORM ACTIVITY AND ASSOCIATED LIGHTNING THAT COULD TRIGGER WILDFIRES.
FORECASTER: ANTHONY ARTUSA
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