369  
ACUS11 KWNS 290301  
SWOMCD  
SPC MCD 290301  
SDZ000-NEZ000-290500-  
 
MESOSCALE DISCUSSION 1501  
NWS STORM PREDICTION CENTER NORMAN OK  
1001 PM CDT SAT JUN 28 2025  
 
AREAS AFFECTED...SOUTHERN SOUTH DAKOTA AND NORTHERN NEBRASKA  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 290301Z - 290500Z  
 
PROBABILITY OF WATCH ISSUANCE...40 PERCENT  
 
SUMMARY...THUNDERSTORMS WILL INCREASE OVERNIGHT NEAR THE  
NEBRASKA/SOUTH DAKOTA BORDER. IF SUFFICIENT CLUSTERING OF  
CONVECTION OCCURS, THEN THERE WILL BE THE POTENTIAL FOR SEVERE  
OUTFLOW GUSTS AND A WATCH MAY NEED TO BE CONSIDERED BY ABOUT 04-05Z.  
 
DISCUSSION...AN EARLIER SUPERCELL HAS DISSIPATED ACROSS SOUTH  
CENTRAL SD, BUT NEW CONVECTION HAS BEEN FORMING TO THE WEST ATOP  
OUTFLOW AND A SURFACE COLD FRONT. AS A 25-35 KT SOUTHERLY LOW-LEVEL  
JET FORMS, WARM ADVECTION ATOP THE FRONTAL SURFACE WILL INCREASE,  
COINCIDENT WITH AN INCREASE IN MIDLEVEL MOISTURE FROM THE WEST THAT  
IS RELATED TO EARLIER HIGH-BASED CONVECTION IN WY/NE PANHANDLE.  
THIS SCENARIO WILL FAVOR AN INCREASE IN ELEVATED CONVECTION NEAR THE  
NE/SD BORDER THROUGH THE OVERNIGHT HOURS. THOUGH THIS CORRIDOR IS  
ALONG THE SOUTHERN EDGE OF THE MIDLEVEL WESTERLIES, MIDLEVEL LAPSE  
RATES REMAIN VERY STEEP (8.5 C/KM OR GREATER) AND PROFILES WILL  
STILL BE FAVORABLE FOR BOTH STRONG UPDRAFTS AND DOWNDRAFTS. IF  
SUFFICIENT CLUSTERING OF STORMS CAN OCCUR, THEN THERE WILL BE SOME  
CONCERN FOR SEVERE OUTFLOW GUSTS AND ISOLATED LARGE HAIL, AND THE  
CONDITIONAL POTENTIAL FOR A SEVERE THUNDERSTORM WATCH BY ROUGHLY  
04-05Z.  
 
..THOMPSON/GUYER.. 06/29/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...FSD...ABR...LBF...UNR...  
 
LAT...LON 42479905 42470128 42620221 43140229 43320186 43610026  
43649893 43239857 42749870 42479905  
 
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
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