705  
ACUS11 KWNS 122235  
SWOMCD  
SPC MCD 122234  
NEZ000-SDZ000-130030-  
 
MESOSCALE DISCUSSION 1959  
NWS STORM PREDICTION CENTER NORMAN OK  
0534 PM CDT WED AUG 12 2026  
 
AREAS AFFECTED...SOUTHWESTERN SOUTH DAKOTA INTO NORTHERN NEBRASKA  
 
CONCERNING...SEVERE THUNDERSTORM WATCH 576...578...  
 
VALID 122234Z - 130030Z  
 
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 576, 578  
CONTINUES.  
 
SUMMARY...DAMAGING WIND AND LARGE HAIL THREAT CONTINUES WITHIN WW576  
AND WW578.  
 
DISCUSSION...A CLUSTER OF SUPERCELLS CONTINUE SOUTHEASTWARD ACROSS  
SOUTHWESTERN SOUTH DAKOTA. THESE HAVE PRODUCED HAIL UP TO 1.75  
INCHES IN DIAMETER AND DAMAGING WIND UP TO 87 MPH. THESE WILL LIKELY  
CONTINUE TO POSE A RISK FOR LARGE HAIL AND DAMAGING WIND DOWNSTREAM  
OVER THE NEXT FEW HOURS, GIVEN THE VERY FAVORABLY UNSTABLE AND  
DEEPLY SHEARED ENVIRONMENT ACROSS WESTERN NEBRASKA, WHERE MLCAPE  
AROUND 1000-2400 J/KG AND DEEP LAYER SHEAR AROUND 45-50 KTS IS  
DEPICTED BY SPC MESOANALYIS. TRENDS IN HI-RES GUIDANCE SUGGEST THAT  
THIS CLUSTER MAY EVENTUALLY INTERACT WITH CONVECTION COMING OUT OF  
COLORADO LATER THIS EVENING, WITH A CONTINUED DAMAGING WIND RISK  
THROUGH THE EVENING.  
 
..THORNTON.. 08/12/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...LBF...UNR...CYS...  
 
LAT...LON 42880340 43090396 43350404 43540393 43640366 43700343  
43750298 43760295 43640232 43310183 43050191 42910202  
42860217 42810234 42880340  
 
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH  
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  
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