598  
ACUS11 KWNS 281947  
SWOMCD  
SPC MCD 281947  
SDZ000-MTZ000-WYZ000-282145-  
 
MESOSCALE DISCUSSION 1493  
NWS STORM PREDICTION CENTER NORMAN OK  
0247 PM CDT SAT JUN 28 2025  
 
AREAS AFFECTED...WESTERN SD...FAR NORTHEAST WY/SOUTHEAST MT  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 281947Z - 282145Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...ISOLATED LARGE HAIL AND LOCALIZED SEVERE GUSTS MAY  
ACCOMPANY INITIAL STORMS ALONG THE NORTH SIDE OF THE BLACK HILLS. A  
SEVERE THUNDERSTORM WATCH ISSUANCE IS POSSIBLE.  
 
DISCUSSION...INITIAL CB DEVELOPMENT IS UNDERWAY NEAR THE MT/WY/SD  
BORDER AREA, WITHIN AN UPSLOPE FLOW, POST-FRONTAL REGIME ALONG THE  
NORTHERN PORTION OF THE BLACK HILLS. THIS OROGRAPHIC ASCENT WILL BE  
NECESSARY TO SUSTAIN STORMS AMID GREATER MLCIN FARTHER SOUTHEAST PER  
THE 18Z UNR SOUNDING. WITH MODERATE MID-LEVEL WEST-SOUTHWESTERLIES  
ATOP THE LOW-LEVEL NORTHERLIES, EFFECTIVE BULK SHEAR WILL BE  
SUFFICIENT FOR SUPERCELL STRUCTURES. WITH A RIBBON OF LOW 60S  
SURFACE DEW POINTS FROM FAR NORTHEAST WY ACROSS NORTHWEST SD,  
MODERATE MLCAPE OF 1500-2000 J/KG SHOULD BE MAINTAINED. LARGE HAIL  
SHOULD BE THE MAIN HAZARD. OVERALL CONVECTIVE COVERAGE MAY REMAIN  
ISOLATED AND LARGELY TIED TO THE TERRAIN THROUGH LATE AFTERNOON.  
 
..GRAMS/HART.. 06/28/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...UNR...BYZ...  
 
LAT...LON 45890260 45460259 44410278 44030353 44390421 44340520  
44420533 44770534 45170507 45820396 45890260  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  
 
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