Severe Thunderstorm Warning 50, NWS Corpus Christi, TX

COASTAL BEND FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
615 PM CDT FRI AUG 8 2003

WENT AHEAD AND CANCELLED THE HEAT ADVISORY FOR THE VICTORIA
CROSSROADS AREA AND THE COASTAL BEND. THE ADVISORY REMAINS
IN EFFECT MAINLY ALONG AND WEST OF HIGHWAY 281 UNTIL 8 PM.

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CONVECTION REMAINS STRONG OVER SOUTH CENTRAL TEXAS NORTH OF THE
VICTORIA CROSSROADS. ACTIVITY IS MOVING SOUTH AT 30 KNOTS. EVEN
IF CAPPING INVERSION REMAINS STRONG...DO NOT SEE THIS ACTIVITY
DISSIPATING. MSAS ANALYSIS SHOWING STRONG MOISTURE CONVERGENCE
OVER THE VICTORIA AREA WITH CAPE VALUES OVER 3000 J/KG. WITH
LARGE TEMPERATURE/DEWPOINT SPREADS AND DOWNDRAFT CAPE OF 1400
J/KG...STRONG DOWNDRAFTS COULD LEAD TO PULSE SEVERE OVER THE
VICTORIA CROSSROADS AREA. WILL UPDATE THE FORECAST TO RAISE
POPS FOR NORTHERN FORECAST AREA AND INSERT SLIGHT CHANCE POPS
FARTHER SOUTH.

89/TMT

PREVIOUS DISCUSSION...

SHORT-TERM (TONIGHT THROUGH SAT NIGHT)...CONVECTION FIRING ALONG THE
OLD FNTL BNDRY IN NORTHEAST TX WL TRY TO MAKE A RUN AT THE VCT AREA
THIS EVE.  WHILE MOST OF THIS CONVECTION SHOULD TEND TO DIMINISH AS
IT ENCOUNTERS A MORE STABLE AND CAPPED AIRMASS...STILL FEEL ISOLATED
POPS ARE JUSTIFIED FOR THIS EVE ACROSS THE VCT AREA.

WHILE THE UPR RDG BASICALLY HOLDS IN PLACE THROUGH THE PD...WE WL
BEGIN TO GET SOME INFLUENCE FROM UPSTREAM CONVECTION AND ASSCTD
MOISTURE TRANSPORT (PWS INCREASE TO 1.7 TO 2.1 INCHES).  IT DOES
APPEAR THAT THE MAIN INITIATION ZONE FOR CONVECTION WL REMAIN WELL
TO OUR NORTH IN THE VCNTY OF A QUASI-STATIONARY FNT AND SHORTWAVE
ENERGY ROTATING AROUND THE MID/UPR RDG AXIS.  MCS ACTIVITY THAT
DEVELOPS ACROSS NORTH TX AND OKLAHOMA THE NEXT FEW NIGHTS WL HAVE A
TOUGH TIME REACHING OUR CWFA.  FEEL TMW NIGHT ANY WEAKENING
CONVECTION AND/OR OUTFLOW WL HAVE A SLIGHTLY BETTER CHC OF AFFECTING
OUR NRN COUNTIES.  THUS...THE CURRENT THINKING IS TO JUST GO WITH
SLIGHT CHC POPS FOR THE NRN ZONES ATTM AND LEAVE THE REMAINDER OF
THE AREA DRY FOR NOW.  OVERALL THE MODELS ARE NOT HANDLING THE
MOISTURE/QPF FIELDS VERY WELL.  THE GFS IS JUST WAY TOO WET AND
HAVING MAJOR FEEDBACK PROBLEMS AND WL BE LARGELY DISCOUNTED.

THE HEAT WAVE DOES BEGIN TO BREAK DOWN TMW AS THE WINDS BECOME MORE
SELY DURING THE DAY AND A LTL MORE CLOUD CVR IS EXPECTED FROM
CONVECTION TO OUR NORTH.  HOWEVER WE STILL MAY BE LOOKING AT HEAT
ADVY LVLS ONCE AGAIN.  THE OVERALL WIND SPEEDS WL REMAIN WEAK TO
OCCASIONALLY MODERATE.  NO FLAGS FOR THE WATERS ARE EXPECTED.

LONG-TERM (SUNDAY THROUGH FRIDAY)...MAIN FORECAST PROBLEM IN THE
LONG TERM IS ASCERTAINING SURFACE PATTERN AND CORRESPONDING TEMPS
AND POPS.  1200 UTC GFS SEEMS TO HAVE SOME FEEDBACK PROBLEMS.
HOWEVER...FOR LATE THIS WEEKEND...AGREE THAT SURFACE AND UPPER
PATTERN BECOMING MORE FAVORABLE FOR MCS DEVELOPMENT OVER N TEXAS
WITH THICKNESS PATTERN AND CORIFIDI VECTOR SUGGESTING A MORE NORTH
TO SOUTH PROPOGATION.  THROUGH MUCH OF NEXT WEEK...CONVECTION SHOULD
BE MAINLY OUTFLOW (MAINLY OVER NE AREAS) OR DIURNALLY SEABREEZE
DRIVEN AS PWATS SHOULD INCREASE AND MID LEVEL TEMPS SHOULD
COOL.

PRELIMS FOLLOW...
CRP BB 076/098 077/094 075 ---22
VCT BB 076/099 077/094 074 11132
LRD BB 081/107 081/102 076 ---11

MB/80...SHORT-TERM
AP/72...LONG-TERM

.CRP...HEAT ADVISORY FOR TXZ229>231-239>241 UNTIL 01Z SATURDAY.

TXZ229>234-239>247-091100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
603 PM CDT FRI AUG 8 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH TEXAS.

.DAY ONE...TONIGHT

SCATTERED THUNDERSTORMS OVER SOUTH CENTRAL TEXAS WILL MOVE SOUTH
INTO THE VICTORIA CROSSROADS REGION THIS EVENING. DAMAGING WIND
GUSTS AND FREQUENT LIGHTNING WILL BE THE SEVERE WEATHER THREATS.
RAINFALL AMOUNTS UP TO 1 INCH MAY BE POSSIBLE WITH THE STRONGER
STORMS.

A HEAT ADVISORY REMAINS IN EFFECT UNTIL 800 PM CDT THIS EVENING
FOR THE PORTIONS OF SOUTH TEXAS MAINLY WEST OF A GEORGE WEST TO
ALICE TO PREMONT LINE.  THE COMBINATION OF HOT TEMPERATURES
AND HIGH HUMIDITY WILL PRODUCE HEAT INDICES BETWEEN 110 AND 115
THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

AFTERNOON TEMPERATURES IN THE MID 90S TO NEAR 107 DEGREES WILL
COMBINE WITH HUMIDITY TO PRODUCE HEAT INDEX VALUES FROM 105 TO 110
DEGREES FOR INLAND SECTIONS OF THE COASTAL BEND AND THE RIO GRANDE
PLAINS SATURDAY. UPPER LEVEL LOW PRESSURE WILL APPROACH THE REGION
EARLY NEXT WEEK ALLOWING A DECREASE IN TEMPERATURES WHILE PROVIDING
ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM ACTIVITY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE POSSIBLE THIS EVENING IN THE VICTORIA
CROSSROADS AREA.

TMT