Flash Flood Warning 70, NWS Corpus Christi, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
400 PM CDT FRI JUN 25 2004

.SHORT-TERM...SEABREEZE BOUNDARY COLLIDED WITH WESTERLY FLOW IN THE
LOWER LEVELS TO CREATE A LOCALIZED BAND OF VERY HEAVY RAINFALL ALONG
THE COAST.  THIS CONVECTION HAS OUTFLOWED OUT AND EXPECT TO SEE SOME
MOVEMENT DURING THE NEXT HOUR AWAY FROM THE HARDEST HIT AREAS.
MEANWHILE WATER VAPOR LOOP TELLS THE STORY...WITH UPPER LOW SPINNING
OVER CENTRAL TEXAS AND A STRONG SHORTWAVE IS MOVING THROUGH NE
MEXICO AND IGNITING LOTS OF CONVECTION TO THE NW OF THE CWA.  MODELS
SEEM TO BE HANDLING THIS PRETTY WELL AND ARE HINTING AT AN EXPLOSION
OF CONVECTION OVER THE WESTERN COUNTIES TONIGHT.  HOWEVER...BELIEVE
THE MODELS ARE TOO SLOW WITH THE TIMING AND WILL BUMP THE SPEED UP.
WITH CAPES OF 4000 J/KG AND DRY AIR ALOFT OVER THE WESTERN COUNTIES
WILL INCLUDE MENTION OF SEVERE THIS EVENING...BUT OVER THE EASTERN
COUNTIES AFTERNOON CONVECTION MAY HAVE STABILIZED THE AIRMASS AND
SEVERE THREAT APPEARS TO BE LOWER.  WILL GO WITH CATEGORICAL POPS
TONIGHT EVERYWHERE...AS I EXPECT AN MCS TO FORM OVER THE WESTERN CWA
AND MOVE EAST ACROSS THE CWA AND EVERYONE SHOULD RECEIVE RAINFALL
WITH THIS SYSTEM.  WILL ALSO TRY TO TREND POPS DOWN TOMORROW AS THE
ATMOSPHERE WILL BE PRETTY WORKED OVER FROM TONIGHTS ACTIVITY.
HOWEVER...GIVEN THE POSITION OF THE UPPER LOW...EASTERN CWA MAY
RECOVER BY TOMORROW AFTERNOON AS THE NEXT SHORTWAVE MOVES THROUGH
DUE TO TRAJECTORY OF RETURN GULF MOISTURE.  NEXT SHIFT CAN ASSES THE
FORECAST FOR SATURDAY...AM RELUCTANT TO GO LESS THAN 50 OR 60 POPS
OVER THE EAST WITH MODELS INDICATING MORE QPF TOMORROW AFTERNOON.
WENT LOWER ON THE TEMPS DUE TO RAIN/CLOUDS.

&&

.LONG-TERM (SATURDAY NIGHT THROUGH FRIDAY)...CONVECTIVE FEEDBACK IN
THE GFS MAKES FORECAST TOUGHER WITH TIME. AVAILABLE MODEL CONSENSUS
SHOWS THE UPPER LOW BEING PICKED BACK UP IN THE WRLY FLOW AND
LIFTING E-NE AWAY FROM THE REGION SATURDAY NIGHT INTO SUNDAY...WITH
MOISTURE SLOWLY DECREASING. SO AFTER A WET START TO THE WEEKEND...IT
LOOKS LIKE SUN COULD TAPER OFF AND HAVE LOWERED POPS SUN FOR JUST
SCT ACTIVITY (ALTHOUGH THIS STILL REMAINS HIGHLY UNCERTAIN).
SUBTROPICAL RIDGE AXIS TRIES TO PUSH INTO THE REGION FROM THE EAST
EARLY NEXT WEEK AS UPPER TROUGH DIGS INTO THE WRN STATES. GFS SHOWS
WEAK S/WVS ROUNDING THIS S/WV AND KEEPING THE RIDGE FROM EVER REALLY
BUILDING INTO THE REGION VERY STRONG. MOISTURE SHOULD BE ADEQUATE TO
CONTINUE LOW END SCT POPS INTO THE MIDDLE OF NEXT WEAK BEFORE MORE
DRYING ALLOWS US TO REMOVE POPS BY FRI. SHOULD NOTE THAT HAVE LEANED
MORE TOWARDS ETA WINDS EARLY IN THE PERIOD AS GFS FIELDS ARE ALL
AFFECTED BY CONVECTIVE FEEDBACK (IE INDUCED LLJ).

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 70 86 74 90 75 / 90 50 40 30 30
VICTORIA       70 85 72 88 74 / 90 60 50 50 50
LAREDO         70 92 74 95 76 / 90 40 40 20 20
ALICE          70 87 73 93 74 / 90 50 40 30 30
ROCKPORT       71 85 76 88 78 / 90 60 50 30 30
COTULLA        69 88 72 94 74 / 90 50 40 40 40

&&

.CRP WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH IN EFFECT
THROUGH 7 AM ALL ZONES.

TR/92...SHORT-TERM
MJG...LONG-TERM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
500 PM CDT FRI JUN 25 2004

GMZ230-235-250-255-270-275-TXZ229>234-239>247-252300-
ARANSAS-BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS-
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT OCONNOR-BEE-CALHOUN-
COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM-
COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM-
DUVAL-GOLIAD-JIM WELLS-KLEBERG-LASALLE-LIVE OAK-MCMULLEN-NUECES-
REFUGIO-SAN PATRICIO-VICTORIA-
WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM-
WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM-WEBB-
500 PM CDT FRI JUN 25 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH TEXAS AND THE ADJACENT
COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT

NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP AND MOVE THROUGH
SOUTH TEXAS THIS EVENING AND TONIGHT.  DUE TO THE SLOW MOVEMENT OF
THE THUNDERSTORMS...HEAVY RAINFALL WILL BE POSSIBLE.  ISOLATED
RAINFALL AMOUNTS OF UP TO 4 INCHES WILL BE POSSIBLE TONIGHT...WITH
MOST LOCATIONS RECEIVING 1 TO 2 INCHES.   ALSO...THERE IS THE
POTENTIAL FOR SEVERE THUNDERSTORMS TO DEVELOP WITH LARGE HAIL AND 60
TO 70 MPH WIND GUSTS EARLY THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

AN UPPER LEVEL DISTURBANCE WILL CONTRIBUTE TO SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS SATURDAY AND SUNDAY. THE MAIN THREAT WILL
BE HEAVY RAINFALL AND POSSIBLE FLOODING. SHOWER AND THUNDERSTORM
ACTIVITY WILL CONTINUE MONDAY THROUGH THURSDAY...HOWEVER THE
COVERAGE AND INTENSITY OF RAINFALL WILL DECREASE SIGNIFICANTLY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT.

TR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
223 PM CDT FRI JUN 25 2004

TXZ229>234-239>246-252010-
ARANSAS-BEE-DUVAL-GOLIAD-JIM WELLS-KLEBERG-LA SALLE-LIVE
OAK-MCMULLEN-NUECES-REFUGIO-SAN PATRICIO-VICTORIA-WEBB-
240 PM CDT FRI JUN 25 2004

...STRONG TO SEVERE THUNDERSTORMS WILL AFFECT MUCH OF THE COASTAL
BEND AND RIO GRANDE PLAINS THIS AFTERNOON AND EVENING...

AT 235 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ACROSS THE COASTAL BEND FROM PORT OCONNOR TO
KINGSVILLE WITH ADDITION SCATTERED STRONG THUNDERSTORMS FORMING OVER
THE RIO GRANDE PLAINS. THROUGH THE REMAINDER OF THE AFTERNOON AND
EARLY EVENING...STRONG THUNDERSTORMS WILL CONTINUE TO INCREASE IN
COVERAGE FILLING IN ACROSS INLAND PORTIONS OF THE COASTAL BEND AND
RIO GRANDE PLAINS. THE STRONGEST STORMS WILL LIKELY DEVELOP IN
WESTERN SECTIONS OF THE COASTAL BEND AND AND ACROSS THE RIO GRANDE
PLAINS.

THESE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING SMALL HAIL...WINDS
GUSTING TO 40 TO 50 MPH...CONTINUOUS LIGHTNING AND TORRENTIAL RAIN
WITH RAINFALL RATES BETWEEN TWO AND THREE INCHES AN HOUR. SOME STORM
TOTAL RAINFALL AMOUNTS COULD APPROACH 3 TO 5 INCHES IN AREAS HARDEST
HIT BY THESE VERY SLOW MOVING STORMS. IN ADDITION SOME STORMS MAY
BECOME SEVERE...ESPECIALLY ALONG AND WEST OF INTERSTATE 37 WEST TO
INTERSTATE 35. SEVERE STORMS THIS AFTERNOON WILL BE CAPABLE OF
PRODUCING PRODUCING DAMAGING WIND GUSTS IN EXCESS OF 60 MPH AND
LARGE HAIL.

STAY TUNED TO NOAA WEATHER RADIO OR LOCAL MEDIA OUTLETS FOR POSSIBLE
SEVERE THUNDERSTORM AND FLASH FLOOD WARNINGS REGARDING THESE
POTENTIALLY DANGEROUS THUNDERSTORMS.

MJG