853  
ACUS01 KWNS 292002  
SWODY1  
SPC AC 292000  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0300 PM CDT SUN JUN 29 2025  
 
VALID 292000Z - 301200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE  
CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS  
OF THE UPPER MIDWEST...  
   
..SUMMARY  
 
ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE  
FROM THE UPPER GREAT LAKES INTO THE CENTRAL HIGH PLAINS. WIND IS THE  
PRIMARY RISK, THOUGH HAIL IS EXPECTED ACROSS PORTIONS OF THE HIGH  
PLAINS.  
   
..20Z UPDATE  
 
THE SLIGHT RISK WAS EXPANDED SOUTHEASTWARD FROM PARTS OF THE CENTRAL  
PLAINS INTO THE MIDDLE MS VALLEY, WHERE A CLUSTER OF THUNDERSTORMS  
IS INTENSIFYING AS IT IMPINGES ON A STRONGLY UNSTABLE AIR MASS. THE  
PRIMARY CONCERN WITH THIS ACTIVITY IS DAMAGING WIND GUSTS. FOR  
INFORMATION ON THE SEVERE RISK HERE, REFERENCE SEVERE THUNDERSTORM  
WATCH 478. ADDITIONALLY, 2-PERCENT TORNADO PROBABILITIES WERE ADDED  
ALONG THIS CORRIDOR AND WESTWARD INTO SOUTHEAST/SOUTH-CENTRAL KS AND  
FAR NORTHEAST/NORTH-CENTRAL OK. HERE, ANTECEDENT OUTFLOW IS  
DIURNALLY DESTABILIZING AMID RICH BOUNDARY-LAYER MOISTURE.  
CLOCKWISE-CURVED LOW-LEVEL HODOGRAPHS WILL SUPPORT A LOCALIZED  
TORNADO RISK WITH ANY CELLS THAT CAN DEVELOP IN THIS CORRIDOR.  
 
FARTHER WEST, SIGNIFICANT-WIND PROBABILITIES WERE ADDED OVER  
NORTHWEST KS, SOUTHWEST NE, AND FAR EASTERN CO. ANY THUNDERSTORM  
CLUSTERS THAT EVOLVE OUT OF CO AND MOVE THROUGH THIS AREA WILL HAVE  
THE POTENTIAL OF PRODUCING GUSTS UPWARD OF 75 MPH -- AIDED BY STEEP  
DEEP-LAYER LAPSE RATES AND SUFFICIENTLY ELONGATED HODOGRAPHS.  
ADDITIONALLY, VISIBLE SATELLITE IMAGERY SHOWS A SHALLOW  
BOUNDARY-LAYER CUMULUS FIELD ALONG A SURFACE WIND SHIFT IN THIS  
GENERAL AREA. AS STORMS MOVE INTO THIS AREA OF ENHANCED MOISTURE AND  
STEEP LAPSE RATES, A BRIEF TORNADO WILL BE POSSIBLE.  
 
REFERENCE SEVERE THUNDERSTORM WATCH 477 AND MCD 1508 FOR THE SEVERE  
RISK IN THE UPPER MIDWEST, AND MCDS 1509 AND 1510 FOR THE HIGH  
PLAINS SEVERE RISK.  
 
..WEINMAN.. 06/29/2025  
   
PREV DISCUSSION  
/ISSUED 1130 AM CDT SUN JUN 29 2025/  
   
..EASTERN KS/WESTERN MO  
 
AN OVERNIGHT MCS IS SLOWLY WEAKENING OVER CENTRAL MO, WITH AN  
ASSOCIATED OUTFLOW BOUNDARY EXTENDING FROM EASTERN KS INTO  
SOUTH-CENTRAL MO. STRONG HEATING WILL OCCUR ALONG AND SOUTH OF THE  
BOUNDARY, WHERE SEVERAL 12Z CAM SOLUTIONS INDICATE DEVELOPMENT OF  
AFTERNOON THUNDERSTORMS. GIVEN THIS SCENARIO, HAVE EXTENDED THE  
SLGT RISK FARTHER SOUTH INTO THIS REGION. LOCALLY DAMAGING WIND  
GUSTS WOULD BE THE MAIN CONCERN. REFER TO MCD #1506 FOR FURTHER  
SHORT-TERM DETAILS.  
   
..WY/CO/SD/NE  
 
A LOW-AMPLITUDE SHORTWAVE TROUGH IS DIGGING INTO WY. AS FORCING  
ASSOCIATED WITH THIS SYSTEM OVERSPREADS THE HIGH PLAINS OF WY,  
HIGH-BASED CONVECTION IS EXPECTED. THUNDERSTORMS WILL INTENSIFY AS  
THEY TRACK INTO A MODERATELY UNSTABLE AIR MASS AND WEAK BUT BACKED  
LOW-LEVEL FLOW. SEVERE STORMS CAPABLE OF LARGE HAIL AND DAMAGING  
WINDS MAY AFFECT THE BLACK HILLS REGION AND SOUTHWARD INTO THE NE  
PANHANDLE.  
 
STORMS WILL ALSO DEVELOP SOUTHWARD INTO THE FOOTHILLS OF CO THIS  
AFTERNOON AND SPREAD EASTWARD. WINDS AND TEMPERATURES ALOFT ARE  
LESS FAVORABLE FOR ORGANIZED/SEVERE STORMS THAT FAR SOUTH, BUT AT  
LEAST ISOLATED INSTANCES OF LARGE HAIL AND DAMAGING WINDS ARE  
POSSIBLE.  
   
..IA/WI  
 
STRONG HEATING IS OCCURRING ACROSS MUCH OF WI TODAY, WHERE A MOIST  
AIR MASS WILL LEAD TO MODERATE CAPE VALUES. THUNDERSTORMS WILL  
DEVELOP BY MID-AFTERNOON ALONG A REMNANT WEAK BOUNDARY ACROSS  
CENTRAL WI/NORTHEAST IA AND SPREAD NORTHEASTWARD THROUGH THE DAY.  
VERTICAL SHEAR IS NOT PARTICULARLY STRONG, AND OVERALL CONVECTIVE  
ORGANIZATION IS EXPECTED TO BE LOW. NEVERTHELESS, STEEP LOW-LEVEL  
LAPSE RATES AND AMPLE INSTABILITY WILL PROMOTE STRONG DOWNDRAFTS AND  
SOME HAIL IN THE STRONGEST CELLS.  
 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page