046
ACUS03 KWNS 301913
SWODY3
SPC AC 301911
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0211 PM CDT TUE JUN 30 2026
VALID 021200Z - 031200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN PLAINS TO THE GREAT LAKES...
..SUMMARY
STRONG TO SEVERE STORMS WILL BE POSSIBLE FROM THE NORTHERN PLAINS
INTO THE MIDWEST AND GREAT LAKES REGIONS ON THURSDAY. ISOLATED
STRONG TO SEVERE STORMS MAY ALSO OCCUR IN THE TENNESSEE
VALLEY/SOUTHEAST AS WELL AS PARTS OF THE NORTHEAST.
..NORTHERN HIGH PLAINS TO THE UPPER MIDWEST
UPPER RIDGING WILL BUILD OVER THE NORTHERN PLAINS ON THURSDAY,
THOUGH TEMPERATURES ALOFT WILL REMAIN FAIRLY COOL AT AROUND -12 TO
-10 C AT 500 MB. A BROAD BELT OF ENHANCED WEST/SOUTHWESTERLY
MID/UPPER-LEVEL FLOW WILL OVERSPREAD THE REGION, AND A SOUTHERLY
LOW-LEVEL JET IS FORECAST TO INTENSIFY ACROSS THE CENTRAL INTO
NORTHERN PLAINS OVERNIGHT. AT THE SURFACE, A QUASI-STATIONARY
BOUNDARY WILL ARC FROM NORTHERN NORTH DAKOTA INTO CENTRAL MN/WI
DURING THE AFTERNOON. MEANWHILE, A SURFACE TROUGH WILL EXTEND
SOUTHWARD ALONG THE HIGH PLAINS. SOUTH/SOUTHEASTERLY LOW-LEVEL FLOW
WILL MAINTAIN A VERY MOIST AIRMASS ACROSS PARTS OF THE CENTRAL
PLAINS INTO THE UPPER MIDWEST, WHILE TRANSPORTING LOW 60S DEWPOINTS
NORTHWEST TO NEAR THE ND/SD/MT/WY BORDER. A BROAD SWATH OF MODERATE
TO STRONG INSTABILITY WILL MATERIALIZE ACROSS THE WARM SECTOR
BUFFERED BY THESE TWO SURFACE BOUNDARIES.
CONVECTION MAY BE ONGOING WHERE FROM THE MID-MO VALLEY TO UPPER
MIDWEST THURSDAY MORNING, THOUGH THIS IS UNCERTAIN. ADDITIONAL
STORMS ARE EXPECTED DURING THE AFTERNOON ALONG THE SURFACE
BOUNDARIES ACROSS THE NORTHERN HIGH PLAINS SOUTHEASTWARD INTO
MN/IA/WI. FORECAST SOUNDINGS SUGGEST SUPERCELL WILL BE POSSIBLE,
WITH AN ACCOMPANYING ALL-HAZARDS RISK POSSIBLE, AT LEAST INITIALLY.
WITH TIME, CONVECTION IN THE HIGH PLAINS SHOULD GROW UPSCALE AND
TRACK SOUTHEAST ALONG THE SURFACE BOUNDARY AND IN THE VICINITY OF
THE TERMINUS OF THE INCREASING LOW-LEVEL JET. THIS ACTIVITY WILL
POSE A RISK OF DAMAGING WIND SWATHS. ADDITIONAL CLUSTERING/MCS
DEVELOPMENT IS POSSIBLE NEAR THE SURFACE BOUNDARY ACROSS MN/WI AND
PERHAPS INTO LOWER MI DURING THE EVENING/OVERNIGHT.
..TN VALLEY VICINITY
ANOTHER MODEST MIDLEVEL SHORTWAVE IMPULSE WILL LIKELY MIGRATE
THROUGH EASTERLY FLOW ON THE SOUTHERN PERIPHERY OF THE UPPER RIDGE
OVER THE EASTERN U.S. A VERY MOIST AND STRONGLY UNSTABLE AIRMASS
WILL ONCE AGAIN SUPPORT A WET MICROBURST RISK, WITH SOME POTENTIAL
FOR SUFFICIENT CLUSTERING TO RESULT IN FORWARD PROPAGATING
CONVECTION. ISOLATED TO WIDELY SCATTERED DAMAGING WIND GUSTS ARE
EXPECTED.
..NORTHEAST
A WEAK COLD FRONT WILL APPROACH THE REGION THURSDAY NIGHT AS A
SURFACE LOW OVER QUEBEC LIFTS NORTHEAST. AHEAD OF THIS FEATURE A
VERY MOIST, HOT, AND UNSTABLE AIRMASS WILL BE IN PLACE. MINOR HEIGHT
FALLS THROUGHOUT THE DAY AND INCREASING WESTERLY FLOW ALOFT WILL
SUPPORT AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT. STRONG/LOCALLY
DAMAGING GUSTS AND HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS.
..LEITMAN.. 06/30/2026
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