Deep sources of endless moisture. Combine with a front and ULL, and you have a potential "waterfall" coming down from the atmosphere! Could get interesting around here if it bullseye's anywhere.

Special Weather Statement
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
430 PM CDT TUE OCT 20 2015
TXZ171>173-183>194-202>209-217>225-228-211200-
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-
INCLUDING THE CITIES OF...LLANO...BURNET...GEORGETOWN...DEL RIO...
ROCKSPRINGS...LEAKEY...KERRVILLE...BANDERA...FREDERICKSBURG...
BOERNE...BLANCO...SAN MARCOS...AUSTIN...BASTROP...GIDDINGS...
BRACKETTVILLE...UVALDE...HONDO...SAN ANTONIO...NEW BRAUNFELS...
SEGUIN...LOCKHART...LA GRANGE...EAGLE PASS...CRYSTAL CITY...
PEARSALL...PLEASANTON...FLORESVILLE...KARNES CITY...GONZALES...
CUERO...HALLETTSVILLE...CARRIZO SPRINGS
430 PM CDT TUE OCT 20 2015
...RAINFALL LIKELY THURSDAY THROUGH SATURDAY NIGHT...
...PERIODS OF LOCALLY HEAVY RAINFALL AND FLOODING POSSIBLE...
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE ACROSS SOUTH
CENTRAL TEXAS ON WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL BECOME
NUMEROUS TO WIDESPREAD THURSDAY THROUGH SATURDAY NIGHT AS UPPER
LEVEL DISTURBANCES AND A COLD FRONT INTERACT WITH DEEP MOISTURE
FROM THE CARIBBEAN AND TROPICAL PACIFIC. THERE IS A POTENTIAL FOR
LOCALLY HEAVY RAINFALL IN SOME SPOTS.
THE BEST CHANCES FOR LOCALLY HEAVY RAINFALL WILL OCCUR THURSDAY
INTO FRIDAY AND SATURDAY INTO SATURDAY NIGHT ALONG AND EAST OF A
KERRVILLE TO PEARSALL LINE. THIS INCLUDES MOST OF THE HILL
COUNTRY...INTERSTATE 35 CORRIDOR...AND COASTAL PLAINS. THIS
INCLUDES THE AUSTIN AND SAN ANTONIO AREAS. THE HEAVY RAINFALL
COULD LEAD TO FLOODING. FLASH FLOODING COULD DEVELOP MORE RAPIDLY
IN BURN AREAS. THE HEAVY RAINFALL AND LIGHTNING COULD LEAD TO
DISRUPTIONS OF OUTDOOR ACTIVITIES. RAINFALL WILL SLOWLY END FROM
WEST TO EAST SUNDAY INTO MONDAY.
TOTAL RAINFALL AMOUNTS FOR WEDNESDAY THROUGH MONDAY COULD REACH 3
TO 6 ALONG AND EAST OF A KERRVILLE TO PEARSALL LINE WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WEST OF THIS LINE...TOTAL RAINFALL
AMOUNTS OF 1 TO 2 INCHES ARE EXPECTED.
ALL INTERESTS IN SOUTH CENTRAL TEXAS ARE URGED TO CLOSELY MONITOR
FORECASTS AS DETAILS ON THIS POTENTIAL HEAVY RAINFALL EVENT BECOME
MORE CLEAR.