612
FXUS01 KWBC 300442
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1240 AM EDT TUE JUN 30 2026
VALID 12Z TUE JUN 30 2026 - 12Z THU JUL 02 2026
...SEVERE THUNDERSTORMS POSSIBLE ACROSS THE NORTH-CENTRAL AND
NORTHEASTERN U.S. THROUGH WEDNESDAY...
...SEVERE THUNDERSTORMS POSSIBLE ACROSS CENTRAL/SOUTHERN PLAINS
THROUGH WEDNESDAY...
...DANGEROUS HEAT FOR THE CENTRAL AND EASTERN U.S.; BELOW NORMAL
TEMPERATURES FOR THE WEST...
A BROAD UPPER-LEVEL TROUGHING OVER WESTERN U.S. WILL SUPPORT
UNSETTLED WEATHER AS FACILITATES THE EASTWARD MOVEMENT OF A
FRONTAL BOUNDARY ACROSS NORTH-CENTRAL U.S. THE STRENGTHENING
CYCLONE TRACKING ACROSS SOUTHERN CANADA WILL DRAG A COLD FRONT
SOUTHEASTWARD THROUGH THE NORTHERN PLAINS AND UPPER MIDWEST BEFORE
REACHING THE GREAT LAKES BY LATE TUESDAY INTO WEDNESDAY. THE
FRONTAL BOUNDARY WILL INTERACT WITH WARM AND UNSTABLE AIR MASS,
WHICH WILL PROMOTE REPEATED ROUNDS OF SHOWERS AND THUNDERSTORMS
FROM THE CENTRAL HIGH PLAINS INTO THE UPPER MIDWEST ON TUESDAY.
ADEQUATE DEEP-LAYER SHEAR AND MODERATE TO STRONG INSTABILITY WILL
SUPPORT ORGANIZED CONVECTION CAPABLE OF SEVERE THUNDERSTORMS,
LARGE HAIL, DAMAGING WINDS, AND EXCESSIVE RAINFALL. THE SEVERE
WEATHER AND EXCESSIVE RAINFALL THREAT SHIFTS EASTWARD INTO
PORTIONS OF THE GREAT LAKES AND NORTHEAST LATE TUESDAY AS A WARM
FRONT LIFT NORTHWARD. SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO
WEDNESDAY ACROSS MUCH OF THE CENTRAL PLAINS INTO THE GREAT LAKES,
BUT A QUASI-STATIONARY FRONT AND SURFACE TROUGH OVER THE
INTERMOUNTAIN WEST/NORTHERN ROCKIES WILL BRING A CHANCE FOR
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA.
FARTHER SOUTH, SCATTERED TO NUMEROUS DIURNALLY ENHANCED
THUNDERSTORMS ARE EXPECTED ALONG THE SLOW-MOVING FRONTAL BOUNDARY
ACROSS THE SOUTHEAST THAT WILL BRING CONCERNS FOR LOCALIZED FLASH
FLOODING. ADDITIONALLY, CONVECTION WILL DEVELOP ACROSS EASTERN NEW
MEXICO AND WEST TEXAS, WHERE PERSISTENT SOUTHEASTERLY LOW-LEVEL
FLOW WILL MAINTAIN MOISTURE CONVERGENCE ALONG THE SOUTHERN HIGH
PLAINS. WHILE STORM CONVERGE SHOULD REMAIN SCATTERED, LOCALIZED
HEAVY RAINFALL MAY LEAD TO ISOLATED FLASH FLOODING CONCERNS,
PARTICULARLY IN TERRAIN-FAVORED LOCATIONS AND URBAN CORRIDORS
THROUGH WEDNESDAY. A SURFACE TROUGH WILL EXTEND SOUTHWARD ACROSS
CENTRAL AND SOUTHERN PLAINS, BRINGING ISOLATED SHOWERS AND
THUNDERSTORMS ON TUESDAY. WITH THE COMBINATION OF SOUTHERLY FLOW
AND INSTABILITY, THE STORMS MAY ALSO PRODUCE SUPERCELLS THAT MAY
BRING A SEVERE THUNDERSTORM THREAT WITH DAMAGING WINDS AND LARGE
TO VERY LARGE HAIL OVER CENTRAL/SOUTHERN HIGH PLAINS THROUGH
WEDNESDAY.
THE DOMINATE WEATHER HAZARD DURING THIS WEEK WILL CONTINUE TO BE
DANGEROUS HEAT ACROSS MUCH OF CENTRAL AND EASTERN U.S.
STRENGTHENING MID-LEVEL HEIGHTS BENEATH THE EXPANSIVE RIDGE WILL
SUPPORT AFTERNOON HIGHS TEMPERATURES IN THE 90S AND LOWER 100S.
INCREASING HUMIDITY VALUES WILL PRODUCE PEAK HEAT INDICES BETWEEN
105-115 DEGREES ACROSS PORTIONS OF THE MIDWEST AND MISSISSIPPI
VALLEY THROUGH THURSDAY, AND EXPANDING INTO THE MID-ATLANTIC AND
OHIO VALLEY BY LATE WEEK. WITH THE COMBINATION OF WARM OVERNIGHT
LOWS, GENERALLY REMAINING IN THE 70S, PROVIDING LIMITED RELIEF AND
PROLONGED DAYTIME, THERE IS AN INCREASED RISK OF HEAT-RELATED
ILLNESSES, ESPECIALLY FOR VULNERABLE POPULATIONS AND THOSE WITHOUT
ADEQUATE COOLING. IN THE WEST, PERSISTENT UPPER-LEVEL TROUGHING
WILL RESULT IN BELOW NORMAL TEMPERATURES ACROSS THE REGION THROUGH
THE WEEK.
OUDIT
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