217  
ACUS11 KWNS 222011  
SWOMCD  
SPC MCD 222010  
NEZ000-COZ000-SDZ000-WYZ000-MTZ000-222215-  
 
MESOSCALE DISCUSSION 1257  
NWS STORM PREDICTION CENTER NORMAN OK  
0310 PM CDT MON JUN 22 2026  
 
AREAS AFFECTED...EASTERN WYOMING AND ADJACENT PORTIONS OF  
NEBRASKA...SOUTH DAKOTA AND FAR SOUTHEAST MONTANA  
 
CONCERNING...SEVERE THUNDERSTORM WATCH 376...  
 
VALID 222010Z - 222215Z  
 
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 376  
CONTINUES.  
 
SUMMARY...THE THREAT FOR LARGE HAIL IS SLOWLY INCREASING ACROSS  
EASTERN WYOMING AND FAR WESTERN NEBRASKA. THIS THREAT WILL GRADUALLY  
SPREAD EAST/SOUTHEAST OVER THE NEXT FEW HOURS.  
 
DISCUSSION...LATEST GOES IR AND MRMS DATA SHOWS STEADY  
INTENSIFICATION OF A TRIO OF SUPERCELLS NEAR THE SHERIDAN, WY AREA  
ALONG WITH MORE ISOLATED CELLS NEAR DOUGLAS, WY AND NEAR KIMBALL,  
NE. ACROSS NORTH/NORTHEAST WY, LOW-LEVEL MOISTURE IS MORE LIMITED,  
BUT INCREASING ASCENT ASSOCIATED WITH THE LEFT-EXIT REGION OF THE  
300 MB JET ALOFT CONTINUES TO OVERSPREAD THE REGION, AIDING IN  
MID-LEVEL COOLING AND COMPENSATING FOR THE OTHERWISE MODEST  
MOISTURE. THIS ASCENT WILL CONTINUE TO PROMOTE STORM INTENSIFICATION  
THROUGH EARLY EVENING AS CELLS SPREAD EAST/SOUTHEAST. RECENT  
FORECAST GUIDANCE AND SARS ESTIMATE HAIL SIZES HINT THAT HAIL SIZES  
WILL MOST LIKELY REACH INTO THE 1-2 INCH RANGE OVER THE NEXT COUPLE  
OF HOURS.  
 
FURTHER SOUTH, STORMS IN EAST-CENTRAL WY TO FAR WESTERN NE CONTINUE  
TO PROPAGATE INTO A PLUME OF RICHER LOW-LEVEL MOISTURE (DEWPOINTS IN  
THE LOW TO MID 50S) WHERE A REGIONAL SBCAPE MAXIMUM IS NOTED (NEAR  
2000 J/KG). CONTINUED LOW-LEVEL MOISTURE ADVECTION COUPLED WITH  
INCREASING MID-LEVEL FLOW ATTENDANT TO THE UPSTREAM MID-LEVEL WAVE  
SHOULD FURTHER AUGMENT THE CONVECTIVE ENVIRONMENT OVER THE NEXT FEW  
HOURS. BY THE 22-00 UTC PERIOD, THE HIGHEST SHIP VALUES SHOULD  
RESIDE FROM EASTERN WY INTO WESTERN NE, SUGGESTING THAT THE GREATEST  
POTENTIAL FOR 2-3 INCH HAIL MAY MANIFEST ACROSS THIS REGION.  
 
..MOORE.. 06/22/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...UNR...BOU...CYS...BYZ...RIW...  
 
LAT...LON 41020409 41600441 42690516 43860632 44660688 44990684  
45300658 45400596 45320544 44630469 43310368 42520320  
41580272 41180270 41030280 40820328 40790367 40830389  
41020409  
 
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  
 
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