940  
ACUS11 KWNS 302021  
SWOMCD  
SPC MCD 302021  
NDZ000-SDZ000-MTZ000-WYZ000-302245-  
 
MESOSCALE DISCUSSION 0906  
NWS STORM PREDICTION CENTER NORMAN OK  
0321 PM CDT SAT MAY 30 2026  
 
AREAS AFFECTED...PARTS OF EASTERN MT...NORTHEAST WY...SOUTHWEST  
ND...NORTHWEST SD  
 
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY  
 
VALID 302021Z - 302245Z  
 
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
 
SUMMARY...ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE THROUGH LATE  
AFTERNOON.  
 
DISCUSSION...OCCASIONALLY STRONG STORMS ARE ONGOING THIS AFTERNOON  
ACROSS EASTERN MT, TO THE NORTHEAST OF A NEGATIVE-TILT MID/UPPER  
SHORTWAVE TROUGH APPROACHING THE CENTRAL/NORTHERN HIGH PLAINS. THIS  
CONVECTION IS ONGOING WITHIN A WEAK TO MODERATELY UNSTABLE  
ENVIRONMENT, WITH GENERALLY LIMITED DEEP-LAYER SHEAR. STORMS IN THIS  
AREA MAY TEND TO REMAIN DISORGANIZED THROUGH THE AFTERNOON, THOUGH  
MARGINALLY SEVERE HAIL AND LOCALIZED STRONG GUSTS CANNOT BE RULED  
OUT IN THE NEAR TERM.  
 
IN THE WAKE OF THIS CONVECTION, DIURNAL HEATING IS UNDERWAY FROM  
NORTHEAST WY/SOUTHEAST MT INTO NORTHWEST SD/SOUTHWEST ND, WHERE  
SOMEWHAT STRONGER INSTABILITY WILL EVOLVE BY LATE AFTERNOON. RENEWED  
STORM INITIATION WILL BE POSSIBLE WITH TIME, WITH THE HIGHEST  
CONFIDENCE IN REDEVELOPMENT NEAR THE BIG HORNS AND NORTHERN PARTS OF  
THE BLACK HILLS. DEEP-LAYER SHEAR WILL GENERALLY REMAIN MODEST, BUT  
A FEW STRONGER MULTICELLS COULD DEVELOP, ACCOMPANIED BY AN ISOLATED  
HAIL THREAT. INCREASINGLY PROMINENT OUTFLOW MAY ALSO LEAD TO  
LOCALIZED STRONG TO SEVERE GUSTS, ESPECIALLY IF ANY STRONGER  
CLUSTERS OR LINE SEGMENTS EVOLVE WITH TIME.  
 
..DEAN/HART.. 05/30/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...BIS...UNR...BYZ...GGW...RIW...  
 
LAT...LON 45160752 45600863 46930848 47620777 47890609 47730487  
47400442 46400349 45630335 44930323 44720353 44560427  
44360502 44150550 44320584 45160752  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
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