935
ACUS11 KWNS 292134
SWOMCD
SPC MCD 292134
IAZ000-MNZ000-SDZ000-NEZ000-292230-
MESOSCALE DISCUSSION 1836
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT TUE JUL 29 2025
AREAS AFFECTED...PORTIONS OF SOUTHERN SOUTH DAKOTA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 292134Z - 292230Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...SEVERE GUSTS MAY ACCOMPANY A MATURE MCS OVER THE NEXT FEW
HOURS. CONDITIONS ARE BEING MONITORED FOR THE NEED OF A SEVERE
THUNDERSTORM WATCH ISSUANCE.
DISCUSSION...AN EASTWARD-PROPAGATING, COLD-POOL-DRIVEN MCS IS IN
PROGRESS ACROSS SOUTHERN SD, AND IS ADVANCING INTO A HIGHLY UNSTABLE
AIRMASS, CHARACTERIZED BY 3000+ J/KG MLCAPE, DRIVEN BY 8 C/KM LAPSE
RATES ATOP 70S F SURFACE DEWPOINTS. VERTICAL WIND SHEAR IS NOT
OVERLY STRONG IN PROXIMITY TO THIS MCS, WITH ONLY 20-30 KTS OF
EFFECTIVE BULK SHEAR IN PLACE, WHICH IS PARALLEL TO THE MCS LINE
ORIENTATION. NONETHELESS, THE STRONG TO EXTREME INSTABILITY AND
ERODING MLCINH IN ADVANCE OF THE MCS SHOULD COMPENSATE FOR ANY
NEGATIVE FACTORS INVOLVING SHEAR MCS INTENSITY TO SUPPORT AT LEAST
SOME ORGANIZED THREAT FOR SEVERE GUSTS. IN ADDITION, THE MORE MIXED
BOUNDARY LAYER IN SOUTHEAST SD WILL SUPPORT HIGHER DCAPE DOWNSTREAM,
WHICH MAY FURTHER AUGMENT THE SEVERE WIND POTENTIAL. EVOLUTION OF
THE MCS WILL BE MONITORED FOR THE NEED OF A SEVERE THUNDERSTORM
WATCH ISSUANCE.
..SQUITIERI/MOSIER.. 07/29/2025
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...FSD...OAX...ABR...LBF...UNR...
LAT...LON 43670070 44119993 44239878 43899676 43539608 43059615
42789659 42729747 42759819 42879884 43129963 43330023
43670070
MOST PROBABLE PEAK WIND GUST...65-80 MPH
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