558  
ACUS01 KWNS 041242  
SWODY1  
SPC AC 041240  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0740 AM CDT SAT APR 04 2026  
 
VALID 041300Z - 051200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER  
GREAT LAKES/OHIO VALLEY...  
   
..SUMMARY
 
 
SEVERE STORMS CAPABLE OF DAMAGING WINDS AND A TORNADO RISK ARE  
EXPECTED ACROSS PARTS OF THE LOWER GREAT LAKES AND MIDDLE/UPPER OHIO  
RIVER VALLEY, MAINLY THIS AFTERNOON THROUGH EARLY EVENING. OTHER  
MORE ISOLATED SEVERE STORMS MAY OCCUR ACROSS THE TENNESSEE VALLEY,  
LOWER MISSISSIPPI VALLEY, AND EASTERN PART OF TEXAS.  
   
..OHIO/EASTERN INDIANA/LOWER MICHIGAN TO PENNSYLVANIA/NEW YORK
 
 
A SHORTWAVE TROUGH OVER THE UPPER MIDWEST EARLY TODAY WILL CONTINUE  
NORTHEASTWARD TOWARD THE UPPER GREAT LAKES THROUGH TONIGHT.  
CYCLONICALLY INFLUENCED STRENGTHENING DEEP-LAYER SOUTHWESTERLIES  
(50+ KT 700 MB) WILL OVERSPREAD INDIANA/MICHIGAN TOWARD THE LOWER  
GREAT LAKES, ATOP A STEADILY MOISTENING/HEATING WARM-SECTOR BOUNDARY  
LAYER ALONG AND NORTH OF THE OHIO RIVER.  
 
THIS WILL BE AHEAD OF A SURFACE LOW AND COLD FRONT, THAT IS  
CONSIDERABLY AUGMENTED BY GENERALLY WEAKENING THUNDERSTORMS AND  
PREVALENT LINGERING CLOUDS/OUTFLOWS THROUGH THE PRE-DAWN HOURS.  
THESE RESIDUAL FACTORS CAST UNCERTAINTY REGARDING THE MAGNITUDE OF  
TODAY'S OVERALL POTENTIAL, BUT A FORMIDABLE FLOW FIELD AND  
GUIDANCE-ADVERTISED HEATING/STEADY DIURNAL DESTABILIZATION WILL  
STILL BE SUPPORTIVE OF AT LEAST SOME SEVERE POTENTIAL REGIONALLY AS  
STORMS REDEVELOP AND INTENSIFY THIS AFTERNOON. THIS INCLUDES  
DAMAGING WIND POTENTIAL, PARTICULARLY GIVEN THE MAGNITUDE OF  
LOW/MID-TROPOSPHERIC WINDS AND BOUNDARY LAYER MIXING, WITH SOME  
TORNADO THREAT AS WELL, MAINLY IN VICINITY OF THE TRIPLE  
POINT/NEARBY WARM FRONT. OVERALL STORM INTENSITIES SHOULD DECREASE  
BY MID/LATE EVENING, OWING TO NOCTURNAL BOUNDARY-LAYER INFLUENCES  
AND THE PRIMARY UPPER-LEVEL SYSTEM SPREADING AWAY FROM THE REGION.  
   
..TENNESSEE VALLEY/LOWER MISSISSIPPI VALLEY/TEXAS
 
 
WHILE DIMINISHING IN INTENSITY OVERNIGHT, SHOWERS/THUNDERSTORMS  
REMAIN EXTENSIVE AND PREVALENT FROM THE MID-SOUTH/OZARKS  
SOUTHWESTWARD INTO NORTH TEXAS, AS A SYNOPTIC COLD FRONT OTHERWISE  
CONTINUES TO PROGRESS SOUTHEASTWARD ACROSS THESE REGIONS. WHILE  
DETAILS ARE COMPLEXIFIED BY CONSIDERABLE CLOUD COVER AND LINGERING  
STORMS, MULTIPLE CORRIDORS OF REINVIGORATING STORMS SHOULD  
MATERIALIZE THIS AFTERNOON WHERE MORE APPRECIABLE CLOUD  
BREAKS/HEATING OCCUR. DOWNBURSTS/LOCALLY DAMAGING WINDS WILL BE THE  
PRIMARY SEVERE HAZARD, BUT THIS IS CURRENTLY EXPECTED TO BE ON A  
RELATIVELY ISOLATED/EPISODIC BASIS.  
 
..GUYER/WEINMAN.. 04/04/2026  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page