344  
ACUS01 KWNS 161615  
SWODY1  
SPC AC 161613  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1113 AM CDT TUE JUN 16 2026  
 
VALID 161630Z - 171200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND  
EVENING ACROSS PARTS OF INDIANA AND LOWER MICHIGAN...AND TONIGHT  
OVER PARTS OF IOWA....  
   
..SUMMARY
 
 
SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND TONIGHT ACROSS  
MULTIPLE PARTS OF THE MIDWEST, AS WELL AS ON A MORE ISOLATED BASIS  
ACROSS THE GULF COAST, SOUTH-CENTRAL PLAINS AND NORTHERN PLAINS.  
   
..IN/LOWER MI
 
 
MORNING WATER VAPOR LOOP SHOWS A STRONG AND PROGRESSIVE CLIPPER  
SYSTEM TRACKING SOUTHEASTWARD ACROSS MN/WI. A BAND OF CLOUDS AND  
ISOLATED THUNDERSTORMS PRECEDES THIS SYSTEM, EXTENDING FROM SOUTHERN  
LOWER MI INTO CENTRAL IL. WHILE A FEW STRONG STORMS ARE POSSIBLE TO  
DEVELOP IN THIS BAND, THE GREATER RISK FOR SEVERE STORMS APPEARS TO  
BE ASSOCIATED WITH A PERIOD OF HEATING IN THE WAKE OF THESE CLOUDS.  
STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT WILL COMBINE WITH  
DEWPOINTS AROUND 60F TO RESULT IN SUFFICIENT AFTERNOON/EVENING CAPE  
FOR WIDELY SCATTERED STRONG/SEVERE STORM DEVELOPMENT. LARGE HAIL  
WILL BE THE INITIAL MAIN CONCERN, ALONG WITH SOME RISK OF A TORNADO  
OR TWO. BY EARLY EVENING, DAMAGING WINDS WILL BE THE MAIN CONCERN.  
   
..IA OVERNIGHT
 
 
THE NEXT IN A SERIES OF FAST-MOVING UPPER-LEVEL FEATURES WILL MOVE  
ACROSS THE DAKOTAS TONIGHT, WITH LARGE-SCALE FORCING FOR ASCENT  
SPREADING INTO PARTS OF MN/IA BEFORE 12Z. THIS ASCENT WILL BEGIN  
INTERACTING WITH A PLUME OF RETURNING MOISTURE, LEADING TO SCATTERED  
THUNDERSTORM DEVELOPMENT IN THE PRE-DAWN HOURS. ELEVATED SUPERCELLS  
CAPABLE OF LARGE HAIL WILL BE THE MAIN RISK THROUGH 12Z.  
   
..MT/ND
 
 
THE AFOREMENTIONED UPPER FEATURE WILL AFFECT NORTHEAST MT AND THE  
DAKOTAS THIS AFTERNOON AND EVENING. A DEEPLY-MIXED BOUNDARY LAYER  
WILL DEVELOP OVER THIS AREA WITH TEMPERATURES IN THE 80S AND 35-45F  
T-TD SPREADS. CAPE WILL BE RATHER WEAK, WHICH SHOULD LIMIT OVERALL  
CONVECTIVE ORGANIZATION. NEVERTHELESS, FAST-MOVING HIGH-BASED  
SHOWERS AND THUNDERSTORMS CAPABLE OF GUSTY AND OCCASIONALLY SEVERE  
WIND GUSTS ARE EXPECTED.  
   
..GULF COAST
 
 
THE TROPICAL SYSTEM (PTC 1) ALONG THE SOUTH TX COAST IS EXPECTED TO  
SLOWLY ORGANIZE TODAY, WITH WIDESPREAD SHOWERS AND THUNDERSTORMS  
FROM EAST TX INTO THE CENTRAL GULF COAST. LOW-LEVEL WINDS ARE NOT  
PARTICULARLY STRONG AND FORECAST HODOGRAPHS ARE ONLY MARGINALLY  
FAVORABLE FOR UPDRAFT ROTATION. NEVERTHELESS WITH SUCH A BROAD AREA  
OF RISK, A TORNADO OR TWO IS CERTAINLY POSSIBLE THIS AFTERNOON  
THROUGH TONIGHT.  
 
..HART/LYONS.. 06/16/2026  
 

 
 
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