775  
ACUS01 KWNS 290458  
SWODY1  
SPC AC 290457  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1157 PM CDT THU AUG 28 2025  
 
VALID 291200Z - 301200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF  
THE SOUTHERN AND CENTRAL HIGH PLAINS...AND IN PARTS OF THE SABINE  
RIVER VALLEY...  
   
..SUMMARY
 
 
THUNDERSTORMS WITH POTENTIAL FOR HAIL AND ISOLATED SEVERE GUSTS WILL  
BE POSSIBLE TODAY ACROSS PARTS OF THE SOUTHERN AND CENTRAL HIGH  
PLAINS. A FEW MARGINALLY SEVERE GUSTS COULD ALSO OCCUR OVER PARTS OF  
THE SABINE RIVER VALLEY.  
   
..SOUTHERN AND CENTRAL HIGH PLAINS
 
 
AT MID-LEVELS, FLOW WILL BE NORTHWESTERLY OVER MUCH OF THE CENTRAL  
U.S. TODAY, AS A RIDGE REMAINS IN PLACE OVER THE CENTRAL HIGH  
PLAINS. AT THE SURFACE, A LOW IS FORECAST TO MOVE EASTWARD THROUGH  
SOUTHWESTERN SOUTH DAKOTA AS A LEE TROUGH DEEPENS ACROSS WESTERN  
NEBRASKA AND EASTERN COLORADO. AS SURFACE TEMPERATURES WARM AND  
LOW-LEVEL CONVERGENCE INCREASES, SCATTERED THUNDERSTORMS ARE  
EXPECTED TO DEVELOP NEAR THE SURFACE TROUGH. ALONG AND TO THE EAST  
OF THE TROUGH, SURFACE DEWPOINTS IN THE LOWER TO MID 60S F WILL  
CONTRIBUTE TO AN AXIS OF MODERATE INSTABILITY BY AFTERNOON. IN  
ADDITION, RAP FORECAST SOUNDINGS ALONG THIS CORRIDOR SHOW MODERATE  
DEEP-LAYER SHEAR, OWING MOSTLY TO SPEED SHEAR IN THE MID-LEVELS.  
THIS INSTABILITY/SHEAR ENVIRONMENT COULD BE ENOUGH FOR A MARGINAL  
SEVERE THREAT LATE THIS AFTERNOON AND EARLY THIS EVENING, WITH THE  
PRIMARY THREATS BEING FOR HAIL AND ISOLATED SEVERE GUSTS.  
   
..SABINE RIVER VALLEY
 
 
A MID-LEVEL TROUGH WILL MOVE ACROSS THE EASTERN U.S. TODAY, AS  
CYCLONICALLY CURVED NORTHWESTERLY FLOW REMAINS OVER MUCH OF THE  
SOUTHEAST. AT THE SURFACE, A SLOW-MOVING FRONT WILL BE POSITIONED  
FROM EAST TEXAS EASTWARD INTO THE CENTRAL GULF COAST STATES.  
THUNDERSTORMS ARE EXPECTED TO BE ONGOING NEAR THE FRONT IN THE  
MORNING. THIS CONVECTION SHOULD MOVE SOUTHEASTWARD ACROSS THE LOWER  
MISSISSIPPI VALLEY DURING THE DAY. TO THE SOUTHWEST OF THIS  
CONVECTION, THE AIRMASS WILL REMAIN UNDISTURBED FROM SOUTHEAST TEXAS  
INTO SOUTHWEST LOUISIANA. THIS WILL ALLOW FOR STRONGER SURFACE  
HEATING, WHICH SHOULD RESULT IN A POCKET OF MODERATE INSTABILITY BY  
AFTERNOON. ISOLATED THUNDERSTORMS THAT DEVELOP WITHIN THIS POCKET OF  
INSTABILITY COULD PRODUCE MARGINALLY SEVERE WIND GUSTS, MAINLY WHEN  
LOW-LEVEL LAPSE RATES BECOME STEEP IN THE MID TO LATE AFTERNOON.  
 
..BROYLES/THORNTON.. 08/29/2025  
 

 
 
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