826
ACUS11 KWNS 122159
SWOMCD
SPC MCD 122159
MIZ000-OHZ000-INZ000-130000-
MESOSCALE DISCUSSION 1937
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT TUE AUG 12 2025
AREAS AFFECTED...SOUTHERN/EASTERN LOWER MI...NORTHERN IN...FAR
NORTHWEST OH
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 122159Z - 130000Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...A THREAT FOR LOCALLY DAMAGING WIND WILL CONTINUE INTO THIS
EVENING.
DISCUSSION...A BAND OF CONVECTION HAS GRADUALLY INTENSIFIED OVER THE
LAST 1-2 HOURS ACROSS PARTS OF CENTRAL/SOUTHERN LOWER MI, WITH A
MORE ISOLATED DISCRETE CELL MOVING ALONG A QUASI-STATIONARY SURFACE
BOUNDARY ACROSS SOUTHEAST LOWER MI. DESPITE POOR MIDLEVEL LAPSE
RATES, RELATIVELY STRONG HEATING AND RICH MOISTURE HAS ALLOWED
MLCAPE TO INCREASE INTO THE 1500-2500 J/KG RANGE DOWNSTREAM OF THE
ONGOING CONVECTION. DEEP-LAYER FLOW IS RELATIVELY MODEST, THOUGH
20-30 KTS OF UNIDIRECTIONAL SOUTHWESTERLY FLOW ALOFT (AS NOTED ON
RECENT VWPS FROM KGRR) MAY ALLOW FOR SOME CONTINUED STORM CLUSTERING
WITH TIME. A THREAT FOR LOCALLY DAMAGING WIND WILL SPREAD EASTWARD
WITH THIS CONVECTION THIS EVENING, ESPECIALLY WHERE STRONGER HEATING
AND STEEPENING OF LOW-LEVEL LAPSE RATES OCCURRED THIS AFTERNOON.
BACKED SURFACE WINDS NEAR/NORTH OF THE BOUNDARY ACROSS SOUTHEAST
LOWER MI WILL LOCALLY ENHANCE EFFECTIVE SHEAR/SRH, AND A TRANSIENT
SUPERCELL OR TWO WITH MARGINAL HAIL POTENTIAL CANNOT BE RULED OUT AS
WELL.
..DEAN/HART.. 08/12/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...DTX...APX...IWX...GRR...
LAT...LON 43318444 44328369 44048260 42778225 42168269 41908342
41408484 40858679 41398665 43318444
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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