Flash Flood Warning 300, NWS Austin/San Antonio, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1231 PM CDT WED JUL 4 2007

.AVIATION...
UPPER LEVEL LOW ACROSS WESTERN DEEP SOUTH TEXAS WILL CONTINUE TO
PULL GULF MOISTURE INTO SOUTH CENTRAL TEXAS. SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE
REGION THROUGH THIS AFTERNOON AND EVENING. AS A RESULT, CONDITIONS
WILL BE QUITE VARIABLE ALONG THE I-35 CORRIDOR THROUGH AT LEAST
00Z. STRATUS DECK WILL CONTINUE TO SLOWLY LIFT...BUT ROUNDS OF
CONVECTION WILL LOWER CIGS/VSBYS TO IFR. EASTERLY SFC WINDS AROUND
10 KTS WILL PREVAIL...WITH GUSTS TO 25 KTS POSSIBLE IN AND NEAR
THUNDERSTORMS THROUGH THIS AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 1023 AM CDT WED JUL 4 2007/

UPDATE...AS THE UPPER LOW MEANDERS ACROSS WESTERN PORTIONS OF
CORPUS CHRISTIS CWA (COUNTY WARNING AREA)..SOUTHEAST AND SOUTH
CENTRAL PORTIONS OF OUR CWA WILL REMAIN VULNERABLE TO VERY HEAVY
RAINS AND RESULTANT FLASH FLOODING. DAYTIME HEATING WILL PRODUCE
WIDESPREAD SCATTERED HEAVY CONVECTION TO OCCUR THIS AFTERNOON
ACROSS MUCH OF OUR CWA. THEN BY LATE TONIGHT..LOW LEVEL JET
REFORMATION WILL BECOME FOCUSED ALMOST PERPENDICULAR TO THE
ESCARPMENT COUNTIES ALONG THE I-35 CORRIDOR AND WITH THE NORTHEAST
QUADRANT OF THE UPPER LOW STILL OVER THE SOUTH CENTRAL
CWA..ADDITIONAL HEAVY RAIN AMOUNTS ARE EXPECTED WHICH MAY AFFECT
THE MAIN STEM MEDINA.. SAN ANTONIO..FRIO AND ATASCOSA RIVERS
THROUGH THE NEXT 24 TO 36 HOUR PERIOD.

PREV DISCUSSION... /ISSUED 328 AM CDT WED JUL 4 2007/

DISCUSSION...
THE UPPER LOW LOCATED ON TOP OF US THIS MORNING AND IS FORECAST TO
SLOWLY WOBBLE TOWARD THE SOUTHWEST ACROSS THE RIO GRANDE INTO
MEXICO OVER THE NEXT 24-48 HOURS. THIS WILL KEEP SOUTH CENTRAL TX
ON THE DANGEROUSLY WET SIDE OF THE UPPER LOW AT LEAST FOR THE NEXT
TWO DAYS AS DEEP GULF MOISTURE FEEDS INTO THE AREA...MAKING FOR
VERY EFFICIENT WARM RAIN PROCESSES ON TOP OF ALREADY SATURATED
SOILS. IN ADDITION WATER VAPOR IMAGERY AND GFS TIME CROSS SECTIONS
INDICATE POSSIBLE UPPER LEVEL SUB-TROPICAL MOISTURE TAP FROM THE
PACIFIC FEEDING INTO THE AREA. HAVE NO CHOICE BUT TO EXTEND THE
FLASH FLOOD WATCH THRU THURSDAY AFTERNOON WITH HEAVIEST RAIN FOCUS
SLOWLY SHIFTING WESTWARD TOWARD THE RIO GRANDE PLAINS BY LATE
TONIGHT/THURSDAY AND POSSIBLY INTO FRIDAY. LONG RANGE GUIDANCE
MOVE REMNANTS OF THE UPPER LOW BACK NWD INTO WEST CENTRAL TX OVER
THE WEEKEND INTO EARLY NEXT WEEK SO HAVE CONTINUED TREND OF LOWER
CHANCE-SLIGHT CHANCE POPS...BUT STAYING ABOVE MEX GUIDANCE POPS
WHICH ALWAYS TREND TOWARD MUCH DRIER CLIMATOLOGY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              83  71  85  72  90 /  70  60  60  40  50
AUSTIN BERGSTROM INTL AIRPORT  82  71  85  72  89 /  70  60  60  40  50
DEL RIO INTL AIRPORT           89  72  89  73  90 /  70  60  70  60  50
SAN ANTONIO INTL AIRPORT       83  72  86  74  90 /  90  60  60  40  50

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR THE FOLLOWING
ZONES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...DIMMIT...EDWARDS...FAYETTE...FRIO...
GILLESPIE...GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...
KINNEY...LAVACA...LEE...LLANO...MAVERICK...MEDINA...REAL...TRAVIS...
UVALDE...VAL VERDE...WILLIAMSON...WILSON...ZAVALA.

&&

02/25

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
502 AM CDT WED JUL 4 2007

TXZ171>173-183>194-202>209-217>225-228-051015-
LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-
GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-
MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-
FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-
502 AM CDT WED JUL 4 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY AND TONIGHT...
A FLASH FLOOD WATCH REMAINS IN EFFECT. AN UPPER LEVEL LOW PRESSURE
SYSTEM OVER SOUTH CENTRAL TEXAS MOVING SOUTHWESTWARD WILL COMBINE
WITH A VERY MOIST UNSTABLE AIRMASS OVER THE AREA. THERE IS A MODERATE
TO HIGH POTENTIAL FOR EXCESSIVE RAINFALL FROM WAVES OF SHOWERS AND
THUNDERSTORMS MOVING ACROSS THE AREA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...
A FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY AFTERNOON. THERE WILL
CONTINUE TO BE A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL AND FLASH FLOODING THROUGH AT LEAST THURSDAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED TODAY THROUGH THURSDAY.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1107 AM CDT WED JUL 04 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1102 AM     FLASH FLOOD      8 WSW SEGUIN            29.54N 98.09W
07/04/2007                   GUADALUPE          TX   LAW ENFORCEMENT

            CREEK RD CLOSED SOUTH OF WEIL RD.

&&

JPB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1130 AM CDT WED JUL 04 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1120 AM     FLASH FLOOD      SAN ANTONIO             29.46N 98.51W
07/04/2007                   BEXAR              TX   DEPT OF HIGHWAYS

            NUMEROUS RDS ACROSS BEXAR COUNTY CLOSED

1120 AM     FLASH FLOOD      MOORE                   29.05N 99.02W
07/04/2007                   FRIO               TX   LAW ENFORCEMENT

            FM 462 CLOSED IN MOORE

1120 AM     FLASH FLOOD      CHARLOTTE               28.86N 98.70W
07/04/2007                   ATASCOSA           TX   DEPT OF HIGHWAYS

            FM140 CLOSED EAST OF CHARLOTTE

&&

JPB