Severe Thunderstorm Warning 243, NWS San Angelo, TX

WEST CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
300 PM CDT TUE AUG 13 2002

AN UPPER LEVEL TROUGH IS DIGGING SOUTH INTO NORTH TEXAS...WEAKENING
THE RIDGE WHICH STRETCHES FROM THE WEST COAST...TO TEXAS. ON THE
SURFACE A COLD FRONT STRETCHES FROM EASTERN WISCONSIN TO SOUTH OF
MIDLAND. THE FRONT IS MAKING SLOW SOUTH/SOUTHEAST PROGRESS NEAR 15
KNOTS BETWEEN LUBBOCK AND ABILENE. TEMPERATURES AHEAD OF THE FRONT
ARE IN THE LOWER 90S...AND 70 TO 80 DEGREES IN THE TEXAS PANHANDLE.
CURRENT RADAR TRENDS SHOW THE CUMULUS FIELD STARTING TO DEVELOP
ALONG THE COLD FRONT.

TONIGHT THROUGH WEDNESDAY NIGHT...
WITH THE COLD FRONT PUSHING SOUTH INTO WEST CENTRAL TEXAS...ALONG
WITH THE MOIST AND UNSTABLE ENVIROMENT ALONG THE FRONT AND WITH
ISENTROPIC LIFT BEHIND THE FRONT...WILL BUMP UP POPS FOR THE
NORTHERN BIG COUNTRY.
ALSO WITH THE STRONG THETA-E RIDGE...GOOD LAPSE RATES AND FULL SUN
AHEAD OF THE FRONT MOVING IN THIS EVENING EXPECT A FEW SEVERE STORMS
POSSIBLE. WITH THE BEST LOW LEVEL SHEAR AND UPPER SUPPORT (RIGHT
ENTRANCE OF AN UPPER JET) TO THE NORTH...THE BEST CHANCE FOR SEVERE
WILL BE ACROSS THE BIG COUNTRY. ALSO WITH PW/S IN THE 1.5 TO 2.0
INCH RANGE EXPECT HEAVY RAIN IN A FEW LOCATIONS ACROSS THE NORTHERN
AND CENTRAL COUNTIES.
BOTH THE AVN AND ETA MODELS ARE SHOWING THE FRONT SLOWLY EDGING
SOUTH THROUGH THE BIG COUNTRY TONIGHT...BEFORE STALLING OUT
SOMEWHERE IN THE CENTRAL OR SOUTHERN COUNTIES. EXPECT THE FRONT TO
STALL OUT...HOWEVER WITH ANY OUTFLOW BOUNDARIES PUSHING SOUTH ACROSS
THE CENTRAL COUNTIES...THIS COULD PUSH THE FRONT TO NEAR INTERSTATE
10.
THE AVN HAS BACKED OFF OF ITS PREVIOUS AGRESSIVENESS...BUT IS STILL
TOO COOL BEHIND THE FRONT...TRYING TO BRING IN 50S FOR THE NORTHERN
BIG COUNTRY. HOWEVER WITH NOTABLY COOLER AFTERNOON TEMPS BEHIND THE
FRONT IN THE PANHANDLE TODAY AND THE FORECAST CLOUD COVER...WILL
DROP HIGHS A CATEGORY ON WEDNESDAY NORTH OF THE FRONT IN THE BIG
COUNTRY.

THURSDAY THROUGH TUESDAY...
THE UPPER LEVEL RIDGE VERY SLOWLY BUILDS IN FROM THE WEST. HOWEVER
THE RIDGE IS NOT EXACTLY ONE OF THOSE TYPICAL DOMINATE TYPES. ONCE
THE WARM FRONT LIFTS OUT...WITHOUT ANY SIGNIFICANT CHANGE THROUGH
NEXT WEEK...WILL CONTINUE WITH THE WARMER (TO NEAR NORMAL) AND DRY
CONDITIONS.

CCF PRELIMS...

ABI 065/085/068/090 4300
SJT 067/089/069/092 3200
JCT 068/090/070/093 2200

.SJT...NONE.

24

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-140-
154-155-168>170-132200-

WEST CENTRAL TEXAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
142 PM CDT TUE AUG 13 2002

...SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WEST
CENTRAL TEXAS THIS AFTERNOON AND TONIGHT...

A COLD FRONT CURRENTLY MOVING INTO NORTH TEXAS ALONG WITH A MOIST
AND UNSTABLE AIRMASS WILL CAUSE THUNDERSTORMS TO FORM LATER THIS
AFTERNOON AND TONIGHT. WINDSHEAR IS ALSO FORECAST TO INCREASE ACROSS
THE BIG COUNTRY LATE THIS AFTERNOON. THIS WILL SET THE STAGE FOR A
FEW SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EARLY TONIGHT. THE
GREATEST POTENTIAL FOR SEVERE THUNDERSTORMS WILL BE NORTH OF A LINE
FROM SAN ANGELO TO BROWNWOOD. THE MAIN THREATS LOOK TO BE STRONG
DAMAGING WINDS AND LARGE HAIL. HOWEVER THUNDERSTORMS THAT MOVE ALONG
ANY BOUNDARIES COULD SPAWN AN BRIEF TORNADO LATE THIS AFTERNOON AND
EARLY EVENING. AT THIS TIME THUNDERSTORM INITIATION LOOKS TO BE
BETWEEN NOW AND 4 PM.

SPOTTER ACTIVATION MAY BE NEEDED...ESPECIALLY OVER THE BIG COUNTRY.