603  
ACUS03 KWNS 131922  
SWODY3  
SPC AC 131921  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0221 PM CDT MON APR 13 2026  
 
VALID 151200Z - 161200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTION OF THE  
SOUTHERN PLAINS INTO SOUTHERN WISCONSIN...  
   
..SUMMARY  
 
SEVERE THUNDERSTORMS POSING A RISK FOR LARGE HAIL AND STRONG WIND  
GUSTS WILL BE POSSIBLE ACROSS PORTIONS OF THE SOUTHERN PLAINS TOWARD  
THE GREAT LAKES ON WEDNESDAY AFTERNOON AND EVENING.  
   
..SYNOPSIS  
 
THE UPPER-LEVEL TROUGH WILL MOVE EASTWARD FROM THE PLAINS INTO THE  
UPPER MIDWEST ON WEDNESDAY, WITH CONTINUED ENHANCED WEST TO  
SOUTHWESTERLY FLOW ACROSS THE SOUTHERN PLAINS INTO THE GREAT LAKES  
REGION. THE SURFACE DRYLINE WILL REMAIN IN A SIMILAR LOCATION FROM  
TUESDAY, EXTENDING ACROSS WESTERN OKLAHOMA INTO SOUTHWESTERN AND  
WESTERN TEXAS. A SURFACE LOW WILL SHIFT EASTWARD ACROSS IA INTO WI,  
WITH A COLD FRONT SHIFTING SOUTH AND EAST THROUGH THE PERIOD.  
SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED FROM THE SOUTHERN  
PLAINS INTO THE UPPER MIDWEST ALONG THE AFOREMENTIONED BOUNDARIES  
WEDNESDAY AFTERNOON AND EVENING.  
   
..SOUTHERN PLAINS TO GREAT LAKES  
 
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL BE ONGOING AT THE  
START OF THE PERIOD AT 12Z WEDNESDAY ACROSS MUCH OF THE SLIGHT RISK  
REGION. A SECONDARY ROUND OF THUNDERSTORM DEVELOPMENT IS LIKELY TO  
OCCUR NEAR AND AHEAD OF THE DRYLINE EXTENDING FROM WEST TEXAS INTO  
WESTERN OKLAHOMA WEDNESDAY AFTERNOON. IT REMAINS SOMEWHAT UNCERTAIN  
HOW MORNING CONVECTION WILL EVOLVE AND WHAT THE RESULTING EFFECT ON  
THE THERMODYNAMIC ENVIRONMENT WILL BE. MOST GUIDANCE SUGGESTS THAT  
IN THE AREA AHEAD OF THE DRYLINE ACROSS CENTRAL OK TO THE RED RIVER  
IN NORTHERN TEXAS WILL DEVELOP AT LEAST MODERATE INSTABILITY  
(1000-2000 J/KG OF MLCAPE). DEEP LAYER SHEAR PROFILES WILL REMAIN  
STRONG FAVORING SUPERCELLS AS THE PRIMARY MODE. THE MAIN THREAT WILL  
BE FOR LARGE TO VERY LARGE HAIL AND DAMAGING WIND, GIVEN LINEARLY  
ELONGATED HODOGRAPHS AND WEAKER LOW-LEVEL SHEAR.  
 
THUNDERSTORMS ARE ALSO EXPECTED TO RE-DEVELOP FURTHER NORTH ACROSS  
THE CENTRAL PLAINS INTO THE GREAT LAKES REGION ALONG THE  
DRYLINE/COLD FRONT INTERSECTION. A MESSY MODE WITH MIX OF SUPERCELLS  
AND MULTI-CELL CLUSTERS IS LIKELY GIVEN THE EVENTUAL SOUTHWARD  
MOVING COLD FRONT. SIMILARLY, THE MAIN RISKS WILL BE FOR DAMAGING  
WIND AND LARGE HAIL ACROSS THESE REGIONS.  
   
..NORTHEAST  
 
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP ALONG AND  
SOUTH OF A DIFFUSE FRONTAL BOUNDARY ACROSS THE GREAT LAKES INTO  
SOUTHERN NY/NORTHERN PA. MODESTLY UNSTABLE PROFILES, STEEPENING  
LAPSE RATES, AND STRONG DEEP LAYER SHEAR WILL ALLOW FOR SOME  
ISOLATED SEVERE STORM RISK. PRIMARY RISK WOULD BE FOR DAMAGING WIND  
AND SMALL HAIL, THOUGH, A TORNADO COULD BE POSSIBLE NEAR THE  
BOUNDARY.  
 
..THORNTON.. 04/13/2026  
 
 
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