975
ACUS03 KWNS 300735
SWODY3
SPC AC 300734
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0234 AM CDT TUE JUN 30 2026
VALID 021200Z - 031200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BLACK
HILLS VICINITY INTO PARTS OF THE MIDWEST...
..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.
..SYNOPSIS
UPPER RIDGING WILL CONTINUE IN THE EAST WITH BROAD CYCLONIC FLOW IN
THE WEST. EMBEDDED SHORTWAVE TROUGHS WILL LIKELY IMPACT THE NORTHERN
PLAINS. ANOTHER SHORTWAVE TROUGH EMBEDDED WITHIN NORTHWESTERLY FLOW
ALOFT WILL MOVE INTO PARTS OF THE NORTHEAST. A STALLED SURFACE
BOUNDARY WILL BE PRESENT FROM THE NORTHERN HIGH PLAINS INTO THE
UPPER MIDWEST WITH A LEE TROUGH/WEAK SURFACE LOW DEVELOPING IN THE
HIGH PLAINS.
..BLACK HILLS INTO IOWA/MINNESOTA
A SUBTLE SHORTWAVE TROUGH IS EVIDENT IN MODEL GUIDANCE. THIS FEATURE
WILL MOVE INTO WYOMING/MONTANA AND EVENTUALLY THE WESTERN DAKOTAS.
CONVECTION APPEARS LIKELY TO DEVELOP WITHIN THE HIGHER TERRAIN (BIG
HORNS/BLACK HILLS) AND MOVE INTO AN AIRMASS WITH INCREASINGLY RICH
LOW-LEVEL MOISTURE TO THE EAST. CONVECTION SHOULD BE ABLE TO
ORGANIZE ALONG THE SURFACE BOUNDARY WITH AROUND 40 KT OF EFFECTIVE
SHEAR PARALLEL TO THE BOUNDARY ITSELF. ADDITIONAL CONVECTION IS ALSO
POSSIBLE ALONG THE STATIONARY FRONT AS LOW-LEVEL WARM ADVECTION
INCREASES. THOUGH THERE IS SOME VARIABILITY IN WHERE ANY EVENTUAL
MCS WILL PROPAGATE, THERE IS ENOUGH CONFIDENCE TO INCLUDE A 15%
SEVERE PROBABILITY AREA THAT ENCOMPASSES THE ENVELOPE OF POTENTIAL
TRACKS. THE ENVIRONMENT WOULD SUPPORT SIGNIFICANT HAIL WITH
SUPERCELLS AND SIGNIFICANT WINDS WITH AN ORGANIZED MCS.
..NORTHEAST
AHEAD OF A COLD FRONT ATTENDANT FROM A SURFACE LOW IN QUEBEC,
CONVECTION WILL BE POSSIBLE DURING THE AFTERNOON. THE TIMING OF THE
CONVECTION, AND THUS THE AVAILABLE BUOYANCY, IS NOT ENTIRELY
CERTAIN. DAMAGING WIND GUSTS AND LARGE HAIL WOULD BE POSSIBLE.
..TENNESSEE VALLEY INTO SOUTHEAST
A SUBTLE EASTERLY WAVE ROTATING AROUND THE UPPER ANTICYCLONE WILL
PROMOTE AFTERNOON CONVECTION WITHIN A VERY MOIST AND UNSTABLE
AIRMASS. GIVEN THE MID-LEVEL LAPSE RATES WILL FAIRLY STEEP, STORMS
WILL LIKELY BE CAPABLE OF DAMAGING DOWNBURST WINDS DESPITE WEAK
SHEAR.
..WENDT.. 06/30/2026
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