Severe Thunderstorm Warning 92, NWS Corpus Christi, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
256 PM CDT TUE AUG 31 2004

.SHORT-TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...GFS/ETA CONSISTENT
WITH A QUASI-STATIONARY UPPER LOW OVR WRN TX...THEN MOVG IT SLOWLY
OVER THE REGION TUESDAY. ASSOCIATED MID/UPPER Q-VECTOR CONVERGENCE
PROGD TO BE WEAK...HOWEVER THE GFS INCREASES UPPER LEVEL DIVERGENCE
SIGNIFICANTLY BY WEDNESDAY NIGHT. GOES SOUNDING INDICATES FAIRLY HIGH
PW VALUES...WITH LOWEST PW VALUES OVR THE NERN CWFA. CONCUR WITH
GFS/ETA THAT PW VALUES WL REMAIN HIGH OVR THE SRN/SWRN CWFA DRG THE
PERIOD. WEAK BNDRY (BASED ON THE MSAS PRESSURE FIELD) CURRENTLY ACRS
THE SRN/WRN CWFA AND WL DISSIPATE DRG THE PD. (ALSO...MSAS DEPICTS A
STRONG THETA-E GRADIENT JUST NORTH OF THE CWFA.) THUS...ISOLD/SCT
CONVECTION TO CONTINUE THIS EVENING IN RESPONSE TO FOREGOING
BNDRYS/INSTABILITY/LOW CIN. COMBINATION OF MSTR/INSTABILITY WL
CONTRIBUTE TO ISOLD/SCT CONVECTION WED...WITH THE GREATEST POPS OVR
THE SWRN BY LATE AFTN/EVENING CONUS OWING TO MSTR/APPROACHING UPPER
DIVERGENCE. UPPER DIVERGENCE NOTWITHSTANDING...ANTICIPATE THAT
INCREASING CIN VALUES TO RESULT IN DECREASING PCPN WEDNESDAY NIGHT.
MARINE...EXPECT WIND/SEAS TO REMAIN BELOW SCA CONDITIONS DRG THE
PERIOD.

&&

.LONG-TERM (THURSDAY THROUGH TUESDAY)...H5 LOW CUT-OFF IN THE MIDDLE
OF THE SUBTROPICAL RIDGE WILL CONTINUE TO SPIN OVER WEST TEXAS
THROUGH THE MIDDLE OF THE WEEK.  IN THE MEANTIME...THIS FEATURE WILL
SPIN A FEW VORT MAXIMA ACROSS THE AREA...PROVIDING CHANCE/SLIGHT
CHANCE POPS.  MAIN FORECAST CHALLENGE WILL BE AMOUNT OF AVAILABLE
BOUNDARY LAYER MOISTURE.  ETA/GFS HAVE SHOWN SIGNIFICANT DIFFERENCES
IN THE HANDLING OF THE MOISTURE RETURN...BUT ARE BEGINNING TO SHOW
SIMILARITIES WITH THE 12Z RUNS.  WITH DRIER AIR FILTERING INTO THE
CWA THROUGH THE NEXT FEW DAYS...SHOULD SEE SOME MOISTURE POOLING
ACROSS THE RIO GRANDE AND SOUTHERN CWA.  WITH SHOW SLIGHT CHANCE
POPS FOR THURSDAY ACROSS THE SOUTHERN AREAS...WITH CHANCE ALONG THE
RIO GRANDE.  ON FRIDAY...SEA-BREEZE SHOULD BE ENHANCE BY THE
AFOREMENTIONED UPPER-LOW OPENING UP AND EJECTING TO THE EAST.  THIS
WILL BRING UPPER-LEVEL SHEAR AXIS ACROSS THE REGION.  WILL SHOW BEST
POPS ACROSS THE SOUTHERN RIO GRANDE PLAINS.  TEMPS WILL RETURN TO
NEAR NORMAL BY THIS TIME.  OVER THE WEEKEND...SHOULD CONTINUE TO SEE
ISOLATED DIURNAL CONVECTION AS MOISTURE INCREASES.  GFS IS SHOWING A
FRONTAL BOUNDARY SLIDING INTO THE REGION ON SUNDAY...WHICH IS QUITE
A BIT FASTER THAN SHOWN YESTERDAY.  WILL REFLECT THIS WITH A WIND
SHIFT LATE SUNDAY/EARLY FRIDAY TO THE ENE.  COULD SEE SOME ACTIVITY
ALONG THE FRONT...BUT WILL GO WITH GHOST POPS AT THIS TIME DUE TO
THE UNCERTAINTY.  CURRENT THINKING IS DRY WEATHER FOR THE FIRST PART
OF NEXT WEEK.  OF COURSE...THIS FORECAST IS DEPENDENT ON HURRICANE
FRANCIS FOLLOWING THE PROJECTED PATH.  IF SHE GETS INTO THE
GULF...SOME CHANGES WOULD BE IN ORDER.

&&

.PRELIMINARY POINT TEMPS/POPS...

CORPUS CHRISTI 71 92 71 92 / 10 30 20 20
VICTORIA       69 93 67 92 / 20 20 10 20
LAREDO         74 94 72 96 / 30 40 30 30
ALICE          70 95 69 94 / 20 30 30 20
ROCKPORT       75 92 74 91 / 10 20 10 20
COTULLA        70 93 66 94 / 30 30 10 20

&&

.CRP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

87/WC...SHORT-TERM
94/MJ...LONG-TERM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
516 AM CDT TUE AUG 31 2004

GMZ230-235-250-255-270-275-TXZ229>234-239>247-011013-
BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS-
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT OCONNOR-
COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM-
COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM-
WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM-
ARANSAS-BEE-CALHOUN-DUVAL-GOLIAD-JIM WELLS-KLEBERG-LA SALLE-LIVE OAK-
MCMULLEN-NUECES-REFUGIO-SAN PATRICIO-VICTORIA-WEBB-
516 AM CDT TUE AUG 31 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT

THE COMBINATION OF A WEAK COLD FRONT SLOWLY APPROACHING THE AREA FROM
THE NORTH...THE AFTERNOON SEA BREEZE AND AN UPPER LEVEL DISTURBANCE
WILL PRODUCE SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN COASTAL BEND
AND THE RIO GRANDE PLAINS MAINLY SOUTH OF A ROCKPORT TO LAKE CORPUS
CHRISTI TO COTULLA LINE. A FEW THUNDERSTORMS ACROSS THIS REGION AND
MAINLY WEST OF HIGHWAY 77 MAY BECOME STRONG PRODUCING FREQUENT
DANGEROUS LIGHTNING STRIKES...WINDS GUSTING TO 40 TO 50 MPH AND VERY
HEAVY RAIN WITH ISOLATED RAINFALL TOTALS OF 1 TO 3 INCHES POSSIBLE.
SLIGHTLY DRIER AIR TO THE NORTHEAST OF THIS REGION WILL CAUSE
THUNDERSTORM COVERAGE TO BE MORE ISOLATED IN NATURE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

A WEAK COLD FRONT WILL BRING ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY THROUGH FRIDAY. DRIER WEATHER AND A
DEVELOPING OFFSHORE WIND ARE EXPECTED SATURDAY THROUGH MONDAY AS
HURRICANE FRANCES CROSSES FLORIDA. WARMING TEMPERATURES AND LOWER
HUMIDITY VALUES WILL DEVELOP THIS WEEKEND AND CONTINUE INTO EARLY
NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

MJG