711  
ACUS11 KWNS 290045  
SWOMCD  
SPC MCD 290044  
NEZ000-SDZ000-290315-  
 
MESOSCALE DISCUSSION 1370  
NWS STORM PREDICTION CENTER NORMAN OK  
0744 PM CDT SUN JUN 28 2026  
 
AREAS AFFECTED...PARTS PF NORTHWESTERN NEBRASKA INTO SOUTHWESTERN  
SOUTH DAKOTA  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 290044Z - 290315Z  
 
PROBABILITY OF WATCH ISSUANCE...60 PERCENT  
 
SUMMARY...INCREASING STRONG THUNDERSTORM DEVELOPMENT APPEARS  
PROBABLE BY LATE EVENING, IF NOT EARLIER. THIS MAY, AT LEAST  
INITIALLY, INCLUDE EVOLVING SUPERCELLS WITH LARGE HAIL AND AT LEAST  
SOME POTENTIAL FOR TORNADOES. ALTHOUGH TIMING REMAINS A BIT  
UNCERTAIN, IT IS APPEARING MORE PROBABLE THAT A SEVERE WEATHER WATCH  
WILL BE NEEDED AT SOME POINT THIS EVENING.  
 
DISCUSSION...WITHIN LARGER-SCALE MID/UPPER TROUGHING ACROSS THE  
WEST, ANOTHER SIGNIFICANT SHORT WAVE TROUGH IS NOW TURNING EASTWARD  
THROUGH THE EASTERN GREAT BASIN AND WILL CONTINUE TO GRADUALLY PIVOT  
EAST-NORTHEASTWARD THROUGH THIS EVENING. THIS MAY BE PRECEDED BY  
ONE OR TWO MUCH MORE SUBTLE PERTURBATIONS WITHIN DOWNSTREAM CYCLONIC  
FLOW ACROSS THE COLORADO ROCKIES TOWARD THE BLACK HILLS VICINITY,  
WITH AT LEAST ATTEMPTS AT ISOLATED THUNDERSTORM DEVELOPMENT NOW  
UNDERWAY NORTHWEST OF MULLEN NE.  
 
THIS STORM APPEARS TO BE DEVELOPING NEAR THE LEADING EDGE OF  
WESTERLY LOW-LEVEL MOISTURE RETURN TOWARD THE HIGH PLAINS BETWEEN  
THE CHEYENNE RIDGE AND BLACK HILLS VICINITY, WHERE FORCING FOR  
ASCENT ASSOCIATED WITH STRENGTHENING WARM ADVECTION CENTERED AROUND  
THE 700 MB LEVEL IS FORECAST TO FOCUS BY 02-04Z. COUPLED WITH  
STRENGTHENING DEEP-LAYER AND LOW-LEVEL SHEAR NEAR THE NOSE OF AN  
INTENSIFYING LOW-LEVEL JET (50-60+ KT AROUND 850 MB), THE POTENTIAL  
FOR SUPERCELL THUNDERSTORM DEVELOPMENT SEEMS LIKELY TO INCREASE  
THROUGH MID TO LATE EVENING, AIDED BY INFLOW OF AIR CHARACTERIZED BY  
INCREASINGLY SIZABLE POTENTIAL INSTABILITY.  
 
..KERR/THOMPSON.. 06/29/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...ABR...LBF...UNR...CYS...  
 
LAT...LON 43240344 44120131 42620001 42340153 41810252 41820354  
43240344  
 
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH  
MOST PROBABLE PEAK WIND GUST...55-70 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