353  
ACUS01 KWNS 290551  
SWODY1  
SPC AC 290550  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1250 AM CDT SUN JUN 29 2025  
 
VALID 291200Z - 301200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER  
MIDWEST TO THE CENTRAL HIGH PLAINS...  
   
..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.  
   
..UPPER GREAT LAKES TO THE CENTRAL HIGH PLAINS
 
 
BROADLY CYCLONIC WESTERLIES, CURRENTLY NOTED OVER THE NORTHERN  
PLAINS, WILL GRADUALLY SHIFT EAST AND SAG SOUTH ACROSS THE UPPER MS  
VALLEY LATE IN THE PERIOD. MID-LEVEL FLOW SOUTH OF I-70 WILL REMAIN  
SEASONALLY WEAK, AND THE PROSPECT FOR ORGANIZED CONVECTION SOUTH OF  
THIS CORRIDOR IS LOW.  
 
EARLY THIS MORNING, A WEAK SYNOPTIC FRONT STRETCHED FROM  
NORTHWESTERN MN INTO NORTHERN NE BEFORE ARCING INTO EASTERN WY. THIS  
BOUNDARY IS FORECAST TO SAG SOUTH AND EAST THROUGH THE PERIOD WITH A  
LATE-AFTERNOON POSITION EXPECTED FROM NORTHERN WI-CENTRAL  
IA-NORTHWEST KS-ARCING INTO SOUTHEAST WY. THIS BOUNDARY WILL LIKELY  
SERVE AS THE FOCUS FOR ROBUST CONVECTION DURING THE  
AFTERNOON/EVENING HOURS. DIURNAL HEATING WILL PROVE INSTRUMENTAL IN  
CONVECTIVE DEVELOPMENT AND THE STRONGEST BOUNDARY-LAYER HEATING WILL  
BE NOTED ACROSS THE HIGH PLAINS INTO EXTREME SOUTHEAST NE.  
CONVECTIVE TEMPERATURES WILL BE EASILY BREACHED ALONG THE BOUNDARY  
OVER NORTHERN KS AS TEMPERATURES SOAR THROUGH THE UPPER 90S TO NEAR  
100F. FORECAST SOUNDINGS EXHIBIT CLOUD BASES NEAR 3KM IN THIS  
ENVIRONMENT AND FAIRLY HIGH PWS FAVOR DAMAGING WINDS DESPITE THE  
RELATIVE WEAK SHEAR ACROSS THIS REGION.  
 
FARTHER NORTHEAST, REMNANTS OF EARLY-DAY CONVECTION WILL SPREAD  
ACROSS SOUTHERN MN/NORTHWEST IA. THIS ACTIVITY WILL PROPAGATE  
SOUTHEAST AND LIKELY INFLUENCE REDEVELOPMENT WHERE DIFFERENTIAL  
HEATING IS GREATEST. SOME SHORT-RANGE GUIDANCE SUGGESTS AN MCS MAY  
PROPAGATE SOUTH ALONG THE NE/IA BORDER, WITH SOME UPSCALE GROWTH  
POSSIBLE BY EARLY EVENING. WHILE NOT ALL MODELS AGREE, THIS SIGNAL  
IS LIKELY REAL, ESPECIALLY AS A WEAK LLJ IS FORECAST ACROSS EASTERN  
KS INTO NORTHWEST MO INTO THE EVENING.  
 
ANOTHER CORRIDOR WHERE STRONG/SEVERE CONVECTION IS EXPECTED IS  
ACROSS THE HIGH PLAINS FROM EASTERN WY INTO NORTHEAST CO. NORTHWEST  
FLOW IS FORECAST TO STRENGTHEN ACROSS THE NORTHERN HIGH PLAINS ALONG  
THE BACK SIDE OF THE TROUGH. ISOLATED SUPERCELLS ARE EXPECTED TO  
DEVELOP ALONG THE SYNOPTIC FRONT THAT WILL BE DRAPED ACROSS THIS  
REGION. FORECAST SOUNDINGS DO NOT EXHIBIT STRONG BUOYANCY, BUT  
MODEST SHEAR AND MOIST PROFILES FAVOR ORGANIZED UPDRAFTS THAT SHOULD  
SPREAD SOUTHEAST TOWARD THE NE PANHANDLE. LARGE HAIL AND WIND ARE  
EXPECTED.  
   
..MIDDLE ATLANTIC
 
 
SEASONALLY HIGH PW VALUES AND LIGHT WEST-SOUTHWESTERLY MID-LEVEL  
FLOW WILL ONCE AGAIN FAVOR A FEW SLOW-MOVING LINE SEGMENTS AND  
CLUSTERS. STORMS WILL BE DIURNALLY DRIVEN, AND CONVECTION SHOULD  
FOCUS ALONG A VERY WEAK ZONE OF LOW-LEVEL CONFLUENCE THAT SHOULD  
EXTEND ACROSS THE DELMARVA INTO CENTRAL VA. LOCALLY STRONG GUSTS ARE  
THE PRIMARY CONCERN.  
 
..DARROW/LYONS.. 06/29/2025  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page