316  
ACUS11 KWNS 171659  
SWOMCD  
SPC MCD 171658  
SDZ000-NEZ000-171830-  
 
MESOSCALE DISCUSSION 0748  
NWS STORM PREDICTION CENTER NORMAN OK  
1158 AM CDT SUN MAY 17 2026  
 
AREAS AFFECTED...SOUTH-CENTRAL SD INTO NORTH-CENTRAL NE  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 171658Z - 171830Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...SEVERE THUNDERSTORM POTENTIAL WILL INCREASE THROUGH EARLY  
AFTERNOON DOWNSTREAM FROM ONGOING ELEVATED CONVECTION ACROSS  
NORTH-CENTRAL NEBRASKA INTO SOUTH-CENTRAL SOUTH DAKOTA. AREA IS  
BEING MONITORED FOR POSSIBLE WATCH ISSUANCE.  
 
DISCUSSION...ELEVATED CONVECTION IS ONGOING AT MIDDAY NEAR THE  
SURFACE COLD FRONT. INFLOW AHEAD OF THIS STORM COMPLEX IS AIDING IN  
NORTHWESTWARD MOISTURE TRANSPORT ACROSS NE AND NEAR A MODIFYING  
OUTFLOW BOUNDARY DRAPED ACROSS NORTH-CENTRAL NE. WITH ADDITION  
HEATING/MOISTENING INTO EARLY AFTERNOON, CONVECTION DEVELOPING ALONG  
THE SOUTHERN FLANK OF THIS STORM COMPLEX MAY EVENTUALLY BECOME  
SURFACE-BASED NEAR THE RESIDUAL OUTFLOW BOUNDARY. STRONGER  
DESTABILIZATION IS EXPECTED INTO THE AFTERNOON AND THIS CURRENTLY  
ELEVATED ACTIVITY MAY GRADUALLY BECOME SURFACE-BASED. UNCERTAINTY  
REMAINS REGARDING HOW THIS AREA OF CONVECTION WILL ULTIMATELY EVOLVE  
AND HOW MUCH SEVERE POTENTIAL WILL ACCOMPANY THIS ACTIVITY IN THE  
SHORT TERM, BEFORE A MORE SUBSTANTIAL RISK DEVELOPS FURTHER EAST  
LATER THIS AFTERNOON. AT LEAST SOME LARGE HAIL AND DAMAGING WIND  
RISK MAY ACCOMPANY INITIAL CONVECTION. TRENDS WILL BE MONITORED AND  
AN INITIAL WATCH ISSUANCE MAY BE NEEDED.  
 
..LEITMAN/MOSIER.. 05/17/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...FSD...ABR...LBF...UNR...  
 
LAT...LON 42870114 43679978 43739910 43339845 42499842 41859885  
41659992 41670077 41850129 42260140 42870114  
 
MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH  
MOST PROBABLE PEAK WIND GUST...65-80 MPH  
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page