649
ACUS01 KWNS 240558
SWODY1
SPC AC 240556
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1256 AM CDT THU JUL 24 2025
VALID 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
MICHIGAN AND THE LOWER GREAT LAKES INTO THE
MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS...
..SUMMARY
LOCALLY DAMAGING THUNDERSTORM WIND GUSTS WILL BE POSSIBLE FROM THE
GREAT LAKES TO THE CENTRAL AND SOUTHERN PLAINS, MAINLY THIS
AFTERNOON AND EVENING. ISOLATED SEVERE STORMS WILL ALSO POSE A RISK
OF LARGE HAIL AND SEVERE WIND GUSTS OVER THE NORTHERN AND CENTRAL
HIGH PLAINS.
..LOWER MI INTO THE LOWER GREAT LAKES
THE MARGINAL RISK HAS BEEN MAINTAINED ACROSS LOWER MI AND ADJACENT
PARTS OF THE GREAT LAKES, THOUGH HIGHER WIND PROBABILITIES MAY
EVENTUALLY BE NEEDED, IF CONFIDENCE INCREASES IN A SUFFICIENT
COVERAGE OF ORGANIZED STORM DEVELOPMENT LATER TODAY INTO THIS
EVENING.
MULTIPLE LOW-AMPLITUDE MIDLEVEL VORTICITY MAXIMA (INCLUDING
POTENTIALLY ONE OR MORE MCVS) WILL MOVE ACROSS PARTS OF THE GREAT
LAKES REGION LATER TODAY, WITHIN A BROADER LARGE-SCALE UPPER-LEVEL
TROUGH. A COLD FRONT WILL MOVE SOUTHEASTWARD ACROSS PARTS OF THE
UPPER MIDWEST AND GREAT LAKES THROUGH THE DAY INTO THE EVENING.
DIURNAL HEATING OF A RICHLY MOIST AIRMASS WILL RESULT IN THE
DEVELOPMENT OF MODERATE BUOYANCY ALONG/AHEAD OF THE FRONT THIS
AFTERNOON. THIS DESTABILIZATION WILL OCCUR BENEATH MODERATE
LOW/MIDLEVEL SOUTHWESTERLY FLOW (25-40 KT IN THE 850-700 MB LAYER).
THE RESULTING ENVIRONMENT WILL BE FAVORABLE FOR OUTFLOW-DOMINANT
STORM CLUSTERS CAPABLE OF WIND DAMAGE.
HOWEVER, DETAILS OF STORM COVERAGE AND TIMING REMAIN UNCERTAIN, DUE
TO WEAK FRONTAL CONVERGENCE AND GENERALLY MODEST LARGE-SCALE ASCENT,
OUTSIDE OF THE POTENTIAL INFLUENCE OF ANY MCVS. THERE IS SOME
POTENTIAL FOR DEVELOPMENT RELATIVELY EARLY IN THE DAY ACROSS
CENTRAL/NORTHERN LOWER MI, WHEN SOMEWHAT STEEPER MIDLEVEL LAPSE
RATES MAY STILL BE IN PLACE. THIS SCENARIO MAY BE THE GREATEST
RELATIVE THREAT FOR ORGANIZED STORMS, THOUGH GUIDANCE VARIES
REGARDING THE COVERAGE OF STORMS THROUGH EARLY AFTERNOON. OTHERWISE,
MIDLEVEL TEMPERATURES WILL TEND TO WARM BY LATER AFTERNOON, THOUGH
ANY STRONGER CELLS/CLUSTERS WOULD STILL BE CAPABLE OF PRODUCING WIND
DAMAGE AS LOW-LEVEL LAPSE RATES STEEPEN.
STORMS MAY SPREAD INTO PARTS OF WESTERN NY FROM ONTARIO LATE THIS
EVENING. WHILE A GENERAL WEAKENING TREND IS EXPECTED BY THIS TIME,
STRONG TO LOCALLY DAMAGING GUSTS CANNOT BE RULED OUT LATE TONIGHT
BEFORE CONVECTION SUBSIDES.
..NORTHERN MO/IL/IN INTO CENTRAL/EASTERN KS AND NORTHERN OK
SCATTERED STORM DEVELOPMENT IS EXPECTED THIS AFTERNOON AND EVENING
FROM CENTRAL/EASTERN KS AND NORTHERN OK INTO PARTS OF NORTHERN
MO/IL/IN, ALONG AND AHEAD OF A COLD FRONT. SOMEWHAT ENHANCED
LOW/MIDLEVEL FLOW WILL BE PRESENT ACROSS NORTHERN IL/IN EARLY IN THE
DAY, BUT GRADUAL WEAKENING OF FLOW IS GENERALLY FORECAST WITH TIME.
FARTHER SOUTHWEST, FLOW IS FORECAST TO REMAIN RATHER WEAK INTO
NORTHERN MO AND THE CENTRAL/SOUTHERN PLAINS. AS A RESULT, STORM
ORGANIZATION MAY TEND TO BE LIMITED, BUT MODERATE TO STRONG BUOYANCY
AND LARGE PW (POTENTIALLY 2 INCHES OR GREATER) WILL SUPPORT A THREAT
OF LOCALIZED DOWNBURSTS. ONE OR MORE SMALL CLUSTERS COULD DEVELOP
AND POSE A THREAT FOR MORE CONCENTRATED WIND DAMAGE, BUT CONFIDENCE
IN THE DETAILS OF THIS POTENTIAL SCENARIO REMAINS LOW.
..HIGH PLAINS
MODERATE BUOYANCY IS EXPECTED TO DEVELOP ACROSS PARTS OF THE CENTRAL
AND NORTHERN HIGH PLAINS THIS AFTERNOON. LARGE-SCALE ASCENT WILL
GENERALLY BE NEBULOUS IN THE WAKE OF A DEPARTING SHORTWAVE TROUGH,
BUT AT LEAST ISOLATED STORM DEVELOPMENT IS POSSIBLE NEAR THE
ADJACENT HIGHER TERRAIN. EFFECTIVE SHEAR OF 30-40 KT WILL SUPPORT
SOME STORM ORGANIZATION. INITIAL DISCRETE CELLS MAY POSE A THREAT OF
HAIL, WHILE SOME OUTFLOW AMALGAMATION COULD EVENTUALLY OCCUR, WITH A
THREAT OF STRONG TO LOCALLY SEVERE GUSTS SPREADING EASTWARD INTO THE
EVENING.
FARTHER SOUTH, SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED INTO
PARTS OF THE SOUTHERN HIGH PLAINS. DEEP-LAYER SHEAR WILL BE WEAK
ACROSS THIS REGION, BUT LOCALIZED STRONG TO SEVERE OUTFLOW GUSTS
WILL BE POSSIBLE.
..DEAN/THORNTON.. 07/24/2025
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