SPC MESOSCALE DISCUSSION 1690 FOR SOUTHERN OKLAHOMA/NORTHERN AND
   WESTERN TEXAS
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
   
   VALID 131900Z - 132200Z
   
   THIS AREA IS BEING MONITORED FOR CONVECTIVE DEVELOPMENT AND A
   POSSIBLE WEATHER WATCH.
   
   LATEST SURFACE ANALYSIS SHOWS A COLD FRONT EXTENDING FROM NEAR HOT
   SPRINGS ARKANSAS...TO NEAR ATOKA OKLAHOMA...TO JUST NORTHWEST OF
   WICHITA FALLS TEXAS TO NORTHWEST OF MIDLAND.  THE AIR MASS SOUTH OF
   THE BOUNDARY REMAINS WARM...MOIST...AND VERY UNSTABLE.  WITH
   TEMPERATURES IN THE LOW 90S...AND DEWPOINTS IN THE LOW TO MID
   70S...SURFACE BASED CAPE VALUES ARE IN THE 3000 TO 4000 J/KG RANGE. 
   HOWEVER...12Z SOUNDINGS FROM MIDLAND AND FORT WORTH SHOW THE
   PRESENCE OF A STRONG CAPPING INVERSION.  SO FAR...THE CAP HAS HELD
   ENOUGH TO LIMIT DEVELOPMENT TO ONLY ISOLATED CELLS IN SOUTHEASTERN
   OKLAHOMA.
   
   THE FRONT IS EXPECTED TO CONTINUE SOUTHWARD THROUGH THE AFTERNOON
   HOURS.  PERSISTENT LOW LEVEL CONVERGENCE ALONG THE FRONT MAY ALLOW
   ADDITIONAL STORMS TO DEVELOPMENT LATER THIS AFTERNOON.  IF THIS
   OCCURS...STORMS WOULD RAPIDLY BECOME SEVERE.  HOWEVER...THERE IS
   STILL CONSIDERABLE UNCERTAINTY AS TO WHETHER THE CAP WILL BREAK. 
   WE WILL CONTINUE TO MONITOR THIS AREA FOR FURTHER DEVELOPMENT.
   
   ..REHBEIN.. 08/13/02