770  
ACUS11 KWNS 272207  
SWOMCD  
SPC MCD 272207  
SDZ000-MTZ000-272330-  
 
MESOSCALE DISCUSSION 1478  
NWS STORM PREDICTION CENTER NORMAN OK  
0507 PM CDT FRI JUN 27 2025  
 
AREAS AFFECTED...PORTIONS OF NORTHWEST AND NORTH-CENTRAL SOUTH  
DAKOTA  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 272207Z - 272330Z  
 
PROBABILITY OF WATCH ISSUANCE...40 PERCENT  
 
SUMMARY...INITIAL HIGH-BASED CONVECTION ACROSS NORTHEAST WY MAY  
PERSIST AND INTENSIFY ACROSS NORTHWEST SD THIS AFTERNOON/EVENING.  
CONFIDENCE IN STORM EVOLUTION IS LOW, BUT A MIX OF SUPERCELLS AND  
CLUSTERS COULD SUPPORT A HAIL AND WIND RISK. CONDITIONS ARE BEING  
MONITORED FOR POSSIBLE WW ISSUANCE.  
 
DISCUSSION...AS OF 22 UTC, REGIONAL OBSERVATIONS SHOWED A COMPLEX  
SURFACE PATTERN EVOLVING ACROSS THE CENTRAL AND NORTHERN HIGH  
PLAINS. SEVERAL THUNDERSTORMS HAVE INITIATED ALONG A WIND SHIFT  
ACROSS THE HIGHER TERRAIN OF NORTHEASTERN WY AS ASCENT FROM A  
MID-LEVEL SHORTWAVE TROUGH HAS MOVED OVERHEAD. WHILE INITIALLY  
HIGH-BASED, THESE STORMS ARE APPROACHING THE WESTERN EDGE OF A VERY  
UNSTABLE WARM SECTOR WITH DEEP SURFACE MOISTURE CONCENTRATED ALONG  
THE NORTHERN PERIPHERY OF THE BLACK HILLS. MODERATE VERTICAL SHEAR  
IS ALSO PRESENT FROM THE UDX VAD SUFFICIENT FOR SUPERCELLS.  
 
RECENT CAM GUIDANCE AND OBSERVATIONAL TRENDS SUGGEST THESE STORMS  
MAY CONTINUE TO INTENSIFY AS THEY MOVE EASTWARD. HOWEVER, THERE  
REMAINS CONSIDERABLE UNCERTAINTY ON THE CONVERGE OF THE STRONGER  
STORMS. THE LARGE BUOYANCY AND SUPPORTIVE SHEAR WOULD FAVOR A RISK  
FOR LARGE TO VERY LARGE HAIL AND DAMAGING GUSTS. THE PRESENCE OF  
MULTIPLE SURFACE BOUNDARIES COULD ALSO SUPPORT A BRIEF TORNADO WITH  
ANY OF THE STRONGER ROTATING STORMS. GIVEN THE INCREASING SEVERE  
POTENTIAL, CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR WW  
ISSUANCE ACROSS PARTS OF NORTHWEST AND NORTH-CENTRAL SD.  
 
..LYONS/GUYER.. 06/27/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...ABR...UNR...BYZ...  
 
LAT...LON 44190288 44310121 45140057 45920066 45920382 45240406  
44620386 44190299 44190288  
 
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH  
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN  
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