Severe Thunderstorm Warning 100, NWS Austin/San Antonio, TX

SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
206 AM CDT FRI JUN 13 2003

SHORT-TERM...
SIGNIFICANT SEVERE/LOCALLY HEAVY RAIN EPISODE APPEARS LIKELY IN THE
NEXT 18 TO 30 HOURS. BOUNDARY FROM NORTHEASTERN TEXAS CONVECTION
LAYS ACROSS FAR NORTHEASTERN CWA WITH DRYLINE RETREATING ACROSS WEST
TEXAS. MEANWHILE, STRONG SHORT-WAVE SEEN ALONG OVER NORTHWESTERN
MEXICO INTO ARIZONA. AIRMASS QUITE MOIST WITH PWS OF 1.7 TO 2.0
ACROSS THE CWA. WILL GO 20 POPS TODAY FOR AIRMASS CONVECTION, WITH
30 IN THE NORTHEAST DUE BOUNDARY WHICH SHOULD SLOWLY DISSIPATE.
TONIGHT INTO SATURDAY THE SHORT-WAVE MOVES ACROSS TEXAS AND PROVIDES
STRONG UPPER DIFFLUENCE. FORECAST CAPES OF 3K TO 4K, HELICITIES OF
100 TO 300, LIS -8 TO -10, AND WEAKENING CIN ALL POINT TO SEVERE
THUNDERSTORMS DEVELOPING OUT WEST WHERE DRYLINE, SHORT-WAVE, AND
MOUNTAINS GENERATE FIRST WITH CORFIDI VECTORS SUGGESTING MOVEMENT
ACROSS CWA. PWS 140 OF AVERAGE INDICATE LOCALLY HEAVY RAINFALL ALSO
POSSIBLE. EXPECT AIRMASS TO BE RECOVERING MOST OF SATURDAY AS UPPER
LOW DEVELOPS IN THE SOUTHERN PLAINS DUE OVERNIGHT SHORT-WAVE SLOWING
AND STALLING AS FLOW ALOFT BUCKLES. COULD BE ANOTHER SIGNIFICANT
EPISODE SATURDAY NIGHT INTO SUNDAY AS MODELS SHOW COOL FRONT AND
ASSOCIATED MCSS TO DROP SOUTH ACROSS CWA. FOR NOW WILL LEAVE OUT
MENTION THOSE PERIODS TO LET LATER SHIFTS FINE TUNE. TEMPERATURES
WILL REMAIN ABOUT A CATEGORY OR SO ABOVE CLIMO, EXCEPT BOUNDARIES
MAY MAKE SOME MINIMUMS LOWER THAN FORECAST.

LONG TERM...
QUASI-STATIONARY UPPER LOW OVER THE SOUTHERN PLAINS OPENS UP ON
TUESDAY, THEN LIFTS OUT WEDNESDAY. THE COOL FRONT STALLS ALONG OR
JUST SOUTH OF THE CWA PROVIDING A FOCUS FOR CONVECTION. ALSO EXPECT
DEVELOPMENT OF THE HIGHER TERRAIN OF WEST TEXAS/NEW MEXICO WHICH
WILL LIKELY SEND MCS ACROSS THE CWA. WILL MAINTAIN RAIN CHANCES
MONDAY THROUGH WEDNESDAY. THURSDAY LOOKS DRY DUE WEAK RIDGING.

PRELIMINARY NUMBERS...
AUS 094/075 092/070 090 36433
DRT 096/074 096/075 094 26233
SAT 094/076 094/074 092 25433

.EWX...NONE.

04/02

TXZ171>173-183>194-202>209-217>225-228-141200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
600 AM CDT FRI JUN 13 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON
MAINLY OVER WESTERN PORTIONS OF SOUTH CENTRAL TEXAS...MAINLY VAL
VERDE...EDWARDS AND KINNEY COUNTIES.  SEVERE THUNDERSTORMS ARE
EXPECTED TO DEVELOP BY LATE AFTERNOON ALONG A DRY LINE OVER
WEST TEXAS AND SPREAD RAPIDLY EASTWARD.  A MODERATE RISK OF
SEVERE STORMS EXISTS THIS EVENING THROUGHOUT ALL OF SOUTH CENTRAL
TEXAS AS A VIGOROUS UPPER AIR DISTURBANCE MOVES ACROSS THE AREA.
THIS INCLUDES THE AUSTIN AND SAN ANTONIO METRO AREAS. LARGE HAIL AND
DAMAGING WINDS MAY OCCUR ALONG WITH A FEW TORNADOES LATE THIS
AFTERNOON AND TONIGHT.

.DAYS TWO THROUGH SEVEN...
ISOLATED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE SATURDAY
THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL LIKELY BE NEEDED LATE THIS AFTERNOON AND
EVENING FOR MUCH OF SOUTH CENTRAL TEXAS AND THE HILL COUNTRY.