254  
ACUS01 KWNS 020101  
SWODY1  
SPC AC 020059  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0759 PM CDT TUE SEP 01 2026  
 
VALID 020100Z - 021200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF  
THE CENTRAL PLAINS AND MIDWEST AS WELL AS THE MID ATLANTIC...  
   
..SUMMARY  
 
SCATTERED STRONG TO SEVERE THUNDERSTORMS REMAIN LIKELY INTO TONIGHT  
ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST, AND  
PARTS OF SOUTHERN NEW YORK INTO THE MID-ATLANTIC. LARGE HAIL AND  
DAMAGING WINDS SHOULD BE THE MAIN THREATS.  
   
..SOUTHERN NY/THE MID ATLANTIC  
 
A MID-LEVEL SHORTWAVE TROUGH AND ENHANCED WEST-NORTHWESTERLY FLOW  
WERE OBSERVED FROM THE NORTHEAST/MID ATLANTIC STATES TO THE LOWER  
GREAT LAKES THIS EVENING. A FRONT WAS DRAPED FROM NORTHWEST TO  
SOUTHEAST ACROSS SOUTHERN NY/NEW ENGLAND, WITH NUMEROUS SHOWERS AND  
STORMS ONGOING ALONG AND SOUTH OF IT THIS EVENING. THE AIR MASS HERE  
IS UNSTABLE AND MODERATELY SHEARED WHICH IS SUPPORTING ORGANIZED  
SUPERCELLS AND SHORT LINEAR SEGMENTS. DAMAGING GUSTS REMAIN LIKELY  
THROUGH THIS EVENING, ALONG WITH SOME HAIL AND PERHAPS A BRIEF  
TORNADO, ESPECIALLY NEAR THE FROM ACROSS SOUTHEASTERN PA AND NJ  
WHERE LOW-LEVEL SEAR IS MAXIMIZED. CONVECTION SHOULD EVENTUALLY  
BEGIN TO WEAKEN WITH THE LOSS OF DIURNAL HEATING AND AS IT  
APPROACHES THE COAST LATER THIS EVENING.  
   
..CENTRAL PLAINS AND MIDWEST  
 
SEVERAL SUPERCELLS HAVE DEVELOPED AHEAD OF A WEAK SURFACE LOW ALONG  
A STALLED FRONT FROM NE INTO SD. A VERY UNSTABLE AIR MASS (MLCAPE OF  
3000+ J/KG) IS IN PLACE AND EXTENDED DOWNSTREAM OF THE CLUSTER  
ACROSS EASTERN SD, NORTHERN IA AND SOUTHERN MN. A BELT OF STRONG  
MID-LEVEL WESTERLY FLOW ALONG THE FRONT WILL CONTINUE TO SUPPORT  
ORGANIZED STORMS. UPSCALE GROWTH IS POSSIBLE THIS EVENING WITH ONE  
OR MORE CLUSTERS OR AN MCS EXPECTED TO EVENTUALLY DEVELOP AND TRACK  
ACROSS PORTIONS OF NORTHERN IA AND FAR SOUTHERN MN. THIS WILL POSE A  
THREAT FOR SEVERE WIND GUSTS AND PERHAPS A TORNADO ALONG THE FRONT  
THROUGH TONIGHT.  
 
FARTHER SOUTHWEST ALONG THE SURFACE LEE TROUGH, SCATTERED HIGH-BASED  
STORMS WERE ONGOING IN EASTERN CO AND WESTERN KS. BUOYANCY AND SHEAR  
ARE MUCH WEAKER, BUT STEEP LAPSE RATES AND T/TD SPREAD OF 30-40  
DEGREES COULD SUPPORT A SPORADIC SEVERE GUSTS WITH THESE STORMS  
BEFORE THEY WEAKEN NEAR SUNSET.  
   
..GREAT LAKES  
 
A SECONDARY MID-LEVEL VORT MAX AND UPPER LOW, CURRENTLY OVER THE  
WESTERN GREAT LAKES, MAY SERVE AS A FOCUS FOR ADDITIONAL STORM  
DEVELOPMENT TONIGHT ACROSS EASTERN WI AND LOWER MI. THE EASTERN  
PORTIONS OF THE QUASI STATIONARY FRONT REMAIN VERY WARM AND  
UNSTABLE. AS ASCENT FROM THE UPPER LOW/SHORTWAVE APPROACH AFTER  
MIDNIGHT, THEY MAY SUPPORT A MODEST ENHANCEMENT OF THE SOUTHWESTERN  
LOW-LEVEL JET. WARM ADVECTION AT THE NOSE OF THIS FEATURE COULD  
ALLOW FOR A CLUSTER OF THUNDERSTORMS TO DEVELOP AND INTENSIFY. THE  
LARGE ELEVATED BUOYANCY AND 40-50 KT WESTERLY FLOW WOULD FAVOR A  
RISK FOR HAIL AND DAMAGING GUSTS BEFORE MOVING INTO SOUTHERN ON BY  
12Z WED. HOWEVER, CONFIDENCE IN HOW THIS SCENARIO EVOLVES REMAINS  
LOW AND ONLY 5% WIND/HAIL PROBABILITIES WILL BE MAINTAINED GIVEN THE  
UNCERTAINTY IN STORM DEVELOPMENT.  
   
..COASTAL SOUTHEAST TEXAS/SOUTHWEST LOUISIANA  
 
TROPICAL STORM EDOUARD WILL CONTINUE TRACKING NORTHWESTWARD ACROSS  
SOUTHEAST TX AND SOUTHWEST LA PER LATEST NHC FORECASTS. SOME  
ENHANCEMENT TO THE LOW-LEVEL WIND FIELD AND HODOGRAPHS HAS BEEN  
NOTED IN OUTER BANDS ALONG THE NORTHERN PORTIONS OF THE CIRCULATION.  
THIS MAY SUPPORT TRANSIENT UPDRAFT ROTATION WITH ANY CELLS. A BRIEF  
TORNADO OR TWO MAY OCCUR ACROSS PARTS OF COASTAL SOUTHEAST  
TX/SOUTHWEST LA THROUGH TONIGHT AS THE SYSTEM WEAKENS.  
 
..LYONS.. 09/02/2026  
 
 
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