Flash Flooding and Hail in Texas, August 20, 2002

SOUTH PLAINS AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
225 PM CDT TUE AUG 20 2002

AT 12Z A BROAD UPPER LEVEL RIDGE WAS LOCATED OVER THE SOUTHERN
CONUS. AN UPPER LEVEL TROUGH WAS DIGGING SOUTHEAST OVER THE PACIFIC
NORTHWEST. A WEAK MID-LEVEL TROUGH WAS LOCATED OVER EXTREME
EASTERN NM AND THE WESTERN HALF OF THE SOUTH PLAINS.

THE 18Z SATELLITE IMAGERY SHOWED THE REMNANT OF THIS MORNING MCS
MOVING NORTHEAST ACROSS THE EASTERN TX PNHDL. THE MCV/WEAK MID-LEVEL
TROUGH WILL CONTINUE TO LIFT NORTHEAST ON THE BACK SIDE OF THE H5
RIDGE AXIS. THE BEST CHANCE FOR THUNDERSTORM DEVELOPMENT LATE THIS
AFTERNOON AND EVENING WILL BE ACROSS THE EASTERN COUNTIES OF THE
CWFA EASTWARD INTO WESTERN OK...EAST OF THE MCV. SUBSIDENCE ON THE
BACK SIDE OF THIS FEATURE MAY STRENGTHEN THE CAP AND PREVENT
THUNDERSTORMS FROM DEVELOPING THIS AFTERNOON ACROSS THE WESTERN AND
CENTRAL COUNTIES OF THE CWFA. THE 18Z SFC MAP SHOWED SFC WINDS
VEERING TO THE SOUTH-SOUTHWEST ACROSS THE WESTERN COUNTIES OF
CWFA...WHILE WINDS ALONG AND EAST OF THE CAP ROCK ESCARPMENT
REMAINED FROM THE SOUTHEAST.  THE WEAK SFC CONVERGENCE MAY PROVIDE
ENOUGH LIFT FOR THUNDERSTORMS TO DEVELOP BY 19 Z EAST OF THE CAP
ROCK ESCARPMENT. THUNDERSTORMS WILL DEVELOP ON THE HIGHER TERRAIN OF
EAST-CENTRAL NM LATE THIS AFTERNOON. THESE STORMS WILL MOVE TO THE
NORTH DUE TO SOUTHERLY FLOW AT MID AND UPPER LEVELS OF THE
ATMOSPHERE. OUTFLOW FROM THE NM STORMS MAY PUSH EAST INTO THE
WESTERN COUNTIES OF THE CWFA THIS EVENING PROVIDING ENOUGH LIFT FOR
THUNDERSTORMS TO DEVELOP.  I WILL GO WITH A 20 POP ACROSS THE
WESTERN AND CENTRAL COUNTIES OF THE CWFA. IF SURFACE CONVERGENCE
CONTINUES TO INCREASE OFF THE CAP ROCK ESCARPMENT LATER THIS
AFTERNOON...I WILL PROBABLY GO WITH SCATTERED THUNDERSTORMS FOR THE
EASTERN COUNTIES.

THE H5 RIDGE AXIS WILL STRENGTHEN ACROSS WEST TX THROUGH SATURDAY AS
THE H5 TROUGH OVER THE PACIFIC NORTHWEST CLOSES OFF AND FILLS.
EXPECT DRY AND WARM CONDITIONS THROUGH FRIDAY.  THE H5 RIDGE OVER
THE SOUTHERN CONUS MAY REMAIN IN PLACE THROUGH THE ENTIRE EXTENDED
FORECAST PERIOD. A WEAK COLD FRONT MAY MOVE SOUTHWARD INTO THE CWFA
ON SUNDAY. THIS MAY PROVIDE THE REGION WITH ONLY A SLIGHT CHANCE OF
THUNDERSTORMS AND SLIGHTLY COOLER AFTERNOON HIGH TEMPERATURES BY
EARLY NEXT WEAK.

FRIONA      068/095/068/095 2-5-
TULIA       068/095/068/094 20-0
LUBBOCK     070/096/070/095 20-0
BROWNFIELD  070/097/069/096 20-0
CHILDRESS   073/101/072/099 50-0
ASPERMONT   075/100/074/098 30-0

.LUB...NONE