088  
ACUS11 KWNS 050759  
SWOMCD  
SPC MCD 050758  
SDZ000-MTZ000-WYZ000-050930-  
 
MESOSCALE DISCUSSION 1889  
NWS STORM PREDICTION CENTER NORMAN OK  
0258 AM CDT TUE AUG 05 2025  
 
AREAS AFFECTED...FAR SOUTHEAST MONTANA...FAR NORTHEAST WYOMING AND  
WESTERN SOUTH DAKOTA.  
 
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY  
 
VALID 050758Z - 050930Z  
 
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
 
SUMMARY...ISOLATED LARGE HAIL IS POSSIBLE EARLY THIS MORNING ACROSS  
PORTIONS OF SOUTHEAST MONTANA, NORTHEAST WYOMING, AND WESTERN SOUTH  
DAKOTA.  
 
DISCUSSION...THE LOW-LEVEL JET HAS STRENGTHENED SIGNIFICANTLY OVER  
THE PAST HOUR ACROSS WESTERN SOUTH DAKOTA (NOW APPROACHING 40 KNOTS  
ON THE KUDX VWP). AS A RESULT, ELEVATED THUNDERSTORMS HAVE INCREASED  
IN COVERAGE ACROSS WESTERN SOUTH DAKOTA AND FAR SOUTHEAST MONTANA.  
AN ENVIRONMENT FEATURING 30 TO 40 KNOTS OF DEEP LAYER SHEAR, 2000 TO  
2500 J/KG MUCAPE, AND SUPPORT FROM THE LOW-LEVEL JET MAY RESULT IN A  
FEW ELEVATED SUPERCELLS CAPABLE OF PRIMARILY LARGE HAIL EARLY THIS  
MORNING. IN ADDITION, A MATURE MCS HAS DEVELOPED ACROSS SOUTHEAST  
MONTANA. AS THIS MCS ADVANCES EAST, AT LEAST SOME SEVERE WIND  
POTENTIAL COULD EXIST IF A MORE CONSOLIDATED/FASTER MOVING SEGMENT  
CAN EMERGE FROM THIS MCS. AT THIS TIME, THE STRONGER STORM IN POWDER  
RIVER, MONTANA WOULD LIKELY HAVE THE GREATEST POTENTIAL FOR THIS  
SOLUTION AS IT MOVES EAST-SOUTHEAST ALONG THE INSTABILITY GRADIENT  
EARLY THIS MORNING. GIVEN THE ISOLATED NATURE OF THE THREAT, A  
SEVERE THUNDERSTORM WATCH IS UNLIKELY.  
 
..BENTLEY/MOSIER.. 08/05/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...UNR...BYZ...  
 
LAT...LON 44850523 45120566 45320572 45520561 45690440 45650320  
45280185 44810143 44080122 43310115 43000191 43020270  
43150354 44010408 44590467 44850523  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
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