861  
ACUS11 KWNS 231924  
SWOMCD  
SPC MCD 231924  
NEZ000-SDZ000-NDZ000-232130-  
 
MESOSCALE DISCUSSION 2100  
NWS STORM PREDICTION CENTER NORMAN OK  
0224 PM CDT SUN AUG 23 2026  
 
AREAS AFFECTED...SOUTHEAST NORTH DAKOTA...WESTERN SOUTH DAKOTA...AND  
PORTIONS OF THE NEBRASKA PANHANDLE  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 231924Z - 232130Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...THE THREAT FOR SEVERE STORMS CAPABLE OF LARGE HAIL UP TO  
TWO INCHES AND SEVERE WIND GUSTS UP TO 75 MPH IS EXPECTED TO  
INCREASE BY MID TO LATE AFTERNOON. A SEVERE THUNDERSTORM WATCH IS  
POSSIBLE.  
 
DISCUSSION...VISIBLE SATELLITE AND LIGHTNING DATA INDICATE INCIPIENT  
THUNDERSTORM DEVELOPMENT OVER THE BLACK HILLS, WHICH IS BEING AIDED  
BY HEATING ALONG THE HIGH TERRAIN AND CONVERGENCE IN THE VICINITY OF  
A SURFACE LOW. THE 18Z RAPID CITY SOUNDING IS LIKELY REPRESENTATIVE  
OF THE AMBIENT ENVIRONMENT, FEATURING MODESTLY STEEP MID-LEVEL LAPSE  
RATES ATOP A MOIST BOUNDARY LAYER WITH MLCAPE OF 1500-2000 J/KG AND  
SOME RESIDUAL CAPPING. WHILE DEEP-LAYER SHEAR ISN'T PARTICULARLY  
STRONG, THE 18Z RIVERTON, WY SOUNDING SAMPLED STRONGER WINDS ABOVE  
5-6 KM AGL, WHICH WILL SPREAD EAST INTO THE REGION LATER THIS  
AFTERNOON.  
 
ELSEWHERE, HIGH-BASED CONVECTION IS DEVELOPING OVER PORTIONS OF  
SOUTHEAST WY INTO THE WESTERN NE PANHANDLE AMIDST A DEEPER,  
WELL-MIXED BOUNDARY. DEEPENING CUMULUS IS ALSO BEING OBSERVED OVER  
FAR EASTERN MT, ALONG AND AHEAD OF A WEAK SURFACE TROUGH. LATEST  
TIME-LAGGED HRRR AND RRFS ENSEMBLE GUIDANCE INDICATES THE POTENTIAL  
FOR WIDELY SCATTERED STORMS TO EVOLVE BY MID TO LATE AFTERNOON FROM  
PARTS OF THE WESTERN DAKOTAS INTO THE NE PANHANDLE, WHICH SEEMS  
REASONABLE BASED ON THE OBSERVATIONAL SIGNALS MENTIONED ABOVE.  
PARAMETER SPACE APPEARS SUPPORTIVE OF ORGANIZED STORM MODES,  
INCLUDING SUPERCELLS CAPABLE OF LARGE HAIL, POTENTIALLY UP TO TWO  
INCHES IN DIAMETER. SEVERE WIND GUSTS UP TO 75 MPH ALSO APPEAR  
POSSIBLE, ESPECIALLY WITH THE STORMS MOVING INTO THE NE PANHANDLE.  
 
CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE SEVERE  
THUNDERSTORM WATCH.  
 
..MEAD/SMITH.. 08/23/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...BIS...LBF...UNR...CYS...  
 
LAT...LON 44000392 44660399 47280403 47290368 47130326 44500268  
42180209 41680239 41640291 42540322 43690382 44000392  
 
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  
 
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