729  
ACUS01 KWNS 090103  
SWODY1  
SPC AC 090101  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0801 PM CDT THU MAY 08 2025  
 
VALID 090100Z - 091200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF  
SOUTH TEXAS...THE TENNESSEE VALLEY...SOUTHERN APPALACHIANS AND  
SOUTHEAST...  
   
..SUMMARY  
 
SCATTERED THUNDERSTORMS WITH SEVERE WIND GUSTS AND LARGE HAIL WILL  
CONTINUE THIS EVENING OVER PARTS OF THE TENNESSEE VALLEY, SOUTHERN  
APPALACHIANS AND SOUTHEAST. SEVERE WIND GUSTS AND LARGE HAIL ARE  
ALSO EXPECTED ACROSS PARTS OF SOUTH TEXAS, WHERE HAILSTONES OF  
GREATER THAN 2 INCHES IN DIAMETER WILL BE POSSIBLE.  
   
..TENNESSEE VALLEY/SOUTHERN APPALACHIANS/SOUTHEAST  
 
LATEST WATER VAPOR IMAGERY SHOWS A POSITIVELY-TILTED MID-LEVEL  
TROUGH OVER THE OHIO VALLEY, WITH AN EAST-TO-WEST ORIENTED PLUME OF  
MID-LEVEL MOISTURE FROM THE MID MISSISSIPPI VALLEY INTO THE SOUTH  
AND CENTRAL APPALACHIANS. AT THE SURFACE, A QUASI-STATIONARY FRONT  
IS ANALYZED IN THE OHIO VALLEY. TO THE SOUTH OF THE FRONT OVER THE  
OHIO AND TENNESSEE VALLEYS, SURFACE DEWPOINTS ARE IN THE MID 50S TO  
THE MID 60S F. THE RAP HAS MODERATE INSTABILITY IN PLACE FROM THE  
TENNESSEE VALLEY EASTWARD INTO THE SOUTHERN APPALACHIANS AND  
SOUTHWARD INTO THE GULF COAST STATES. SCATTERED THUNDERSTORMS ARE  
ONGOING, CONCENTRATED ALONG THE NORTHERN EDGE OF MODERATE  
INSTABILITY FROM KENTUCKY AND TENNESSEE EASTWARD INTO WESTERN NORTH  
CAROLINA. RAP FORECAST SOUNDINGS IN THIS VICINITY EARLY THIS EVENING  
HAVE 0-6 KM SHEAR RANGING FROM 35 TO 45 KNOTS, MOSTLY DUE TO SPEED  
SHEAR IN THE MID-LEVELS. THIS, COMBINED WITH 0-3 KM LAPSE RATES IN  
THE 7.5 TO 8 C/KM RANGE, SHOULD BE FAVORABLE FOR SEVERE GUSTS WITH  
THE STRONGER CELLS. THE SHEAR WILL ALSO SUPPORT SUPERCELL  
DEVELOPMENT WITH LARGE HAIL POSSIBLE. THE SEVERE THREAT SHOULD  
BECOME MORE ISOLATED LATER THIS EVENING AS INSTABILITY DECREASES  
ACROSS THE REGION.  
   
..SOUTH TEXAS  
 
A SHORTWAVE TROUGH, WITH MULTIPLE VORTICITY MAXIMUMS, APPEARS TO BE  
LOCATED IN THE LOWER RIO GRANDE VALLEY, ACCORDING TO WATER VAPOR  
IMAGERY. SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING AHEAD  
OF THE TROUGH FROM NEAR LAREDO EXTENDING EASTWARD ONTO THE TEXAS  
COASTAL PLAIN. FROM THE STORMS SOUTHWARD, MODERATE INSTABILITY IS  
ANALYZED BY THE RAP, WITH MLCAPE ESTIMATED TO BE IN THE 1000 TO 2000  
J/KG RANGE. THE AIRMASS IS VERY MOIST WITH SURFACE DEWPOINTS IN THE  
LOWER TO MID 70S F. WITHIN THIS MOIST AIRMASS, RAP FORECAST  
SOUNDINGS EARLY THIS EVENING HAVE 0-6 KM SHEAR NEAR 50 KNOTS, WITH  
700-500 MB LAPSE RATES NEAR 7.5 C/KM. THIS ENVIRONMENT WILL SUPPORT  
SUPERCELLS WITH LARGE HAIL, AND HAILSTONES GREATER THAN 2 INCHES IN  
DIAMETER WILL BE POSSIBLE WITHIN THE MORE INTENSE CORES. ISOLATED  
SEVERE GUSTS MAY ALSO OCCUR WITHIN THE STRONGER DOWNDRAFTS. THE  
ONGOING SEVERE STORMS WILL TRACK SOUTHEASTWARD ACROSS THE REMAINDER  
OF SOUTH TEXAS THIS EVENING...SEE MCD 749.  
 
..BROYLES.. 05/09/2025  
 
 
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