565  
ACUS01 KWNS 090543  
SWODY1  
SPC AC 090541  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1241 AM CDT WED SEP 09 2026  
 
VALID 091200Z - 101200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN OHIO  
INTO WESTERN NEW YORK...  
   
..SUMMARY
 
 
ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS  
OF THE CENTRAL PLAINS TO THE OHIO VALLEY ON WEDNESDAY. A MORE  
ORGANIZED SEVERE WEATHER THREAT IS EXPECTED FROM EASTERN OHIO TO  
WESTERN NEW YORK.  
   
..SYNOPSIS
 
 
A BELT OF ENHANCED MID-LEVEL FLOW WILL MOVE THROUGH THE BROAD  
UPPER-LEVEL TROUGH ACROSS ONTARIO, OVERSPREADING THE GREAT LAKES  
INTO UPSTATE NEW YORK AND QUEBEC. A COLD FRONT WILL EXTEND FROM A  
DEEP SURFACE LOW ACROSS NORTHERN ONTARIO SOUTH THROUGH THE UPPER  
MIDWEST AND INTO THE CENTRAL HIGH PLAINS. ISOLATED TO WIDELY  
SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED NEAR THE SURFACE TROUGH  
ACROSS THE OHIO VALLEY INTO THE NORTHEAST AND ALONG THE FRONT FROM  
THE MIDWEST TO THE CENTRAL HIGH PLAINS.  
   
..EASTERN OHIO INTO WESTERN NEW YORK
 
 
ACROSS THE EASTERN OHIO VALLEY INTO PORTIONS OF THE NORTHEAST,  
STRENGTHENING MID-LEVEL FLOW WILL OVERSPREAD THE REGION WITH  
THUNDERSTORMS DEVELOPING ALONG THE COLD FRONT AND PRE-FRONTAL  
SURFACE TROUGH. UPPER 60S TO 70S DEW POINTS AND FILTERED DAYTIME  
HEATING WILL YIELD MODERATE INSTABILITY AMID AMPLE DEEP LAYER SHEAR  
FOR ORGANIZATION. MODE WILL LIKELY BE A MIX OF MULTI-CELL CLUSTERS  
AND TRANSIENT SUPERCELLS, WITH POTENTIAL FOR DAMAGING WIND.  
GENERALLY WEAK LAPSE RATE PROFILES AND QUICK MODE TRANSITION TO  
CLUSTERS/LINEAR SEGMENTS SHOULD LIMIT HAIL AND TORNADO POTENTIAL.  
NONETHELESS, AS THE LOW-LEVEL JET INCREASES INTO THE AFTERNOON AND  
CLOCKWISE CURVATURE INCREASES IN HODOGRAPHS A TORNADO MAY BE  
POSSIBLE.  
   
..OHIO VALLEY TO THE MIDWEST AND THE CENTRAL PLAINS
 
 
MORNING CONVECTION WILL BE LIKELY ACROSS MUCH OF THE  
MIDWEST/MID-MISSOURI VALLEY INTO THE NORTHWESTERN OHIO VALLEY.  
REMNANT SHOWER ACTIVITY/CLOUD COVER WILL LIKELY LIMIT SEVERE  
POTENTIAL WITH NORTHERN EXTENT. NONETHELESS, ISOLATED TO WIDELY  
SCATTERED THUNDERSTORM ACTIVITY IS EXPECTED TO DEVELOP BY THE  
AFTERNOON ALONG THE FRONT AND REMNANT OUTFLOW FROM THE EASTERN OHIO  
VALLEY THROUGH PORTIONS OF THE MIDWEST AND INTO THE CENTRAL PLAINS.  
FLOW WILL BE FAIRLY WEAK ACROSS THE CENTRAL PLAINS, WITH GENERALLY A  
MARGINAL DAMAGING WIND THREAT WITH MULTI-CELL CLUSTERS AS DAYTIME  
HEATING STEEPENS LOW-LEVEL LAPSE RATES AMID DEEPLY MIXED PROFILES.  
SLIGHTLY BETTER FLOW ALOFT MAY FAVOR A MORE FOCUSED CLUSTER ACROSS  
THE MID-MISSISSIPPI VALLEY INTO WESTERN KENTUCKY/TENNESSEE.  
 
..THORNTON/CHALMERS.. 09/09/2026  
 

 
 
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