SPC MESOSCALE DISCUSSION 0693 FOR NWRN/CNTRL TX
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 071744Z - 072100Z

ISOLATED THUNDERSTORMS OVER NORTHWEST TEXAS MAY INCREASE IN
INTENSITY/COVERAGE OVER THE NEXT COUPLE OF HOURS AS THEY
MOVE/DEVELOP SOUTHWARD.  A SEVERE THUNDERSTORM WATCH IS POSSIBLE IN
THE NEXT 2 HOURS.  

LATEST ANALYSIS INDICATES COLD FRONT FROM CENTRAL OKLAHOMA TO NEAR
MIDLAND TEXAS.  AN OUTFLOW BOUNDARY FROM OVERNIGHT THUNDERSTORMS
OVER NORTH CENTRAL TEXAS INTERSECTS THE COLD FRONT NEAR ABILENE TX. 
AS THE BOUNDARIES COLLIDED IN THE PAST HOUR...THUNDERSTORMS HAVE
DEVELOPED BETWEEN WICHITA FALLS AND ABILENE.  

PROFILER FROM JAYTON TX INDICATES VERTICAL WIND SHEAR IS SUPPORTIVE
OF SUPERCELLS...WITH 0-6 KM VALUE AROUND 40 KNOTS.  AIRMASS IS
ALREADY MODERATELY UNSTABLE WITH MLCAPE OF 1500-2000 J/KG...AND
ADDITIONAL HEATING WILL RESULT IN CONTINUED DESTABILIZATION. 
SUFFICIENT LOW LEVEL CONVERGENCE ALONG BOUNDARIES PLUS
FRONTOGENETIC EFFECT OF DIFFERENTIAL HEATING DUE TO CLOUD COVER
BEHIND FRONT SHOULD RESULT IN INITIATION OF ADDITIONAL
THUNDERSTORMS DURING THE AFTERNOON.  IF COVERAGE OF STORMS
CONTINUES TO INCREASE...THEN A SEVERE THUNDERSTORM WATCH WILL BE
REQUIRED.      

..CRAVEN.. 05/07/01