Flash Flood Warning 328, NWS Austin/San Antonio, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
418 AM CDT SAT JUL 7 2007

.DISCUSSION...
EARLY MORNING ROUND OF THUNDERSTORMS ARE CONFORMING NICELY TO THE
LATEST FFA PRODUCT. THE THREAT FOR HEAVY RAINFALL WILL PERSIST FOR
A GREATER AREA OF SOUTH CENTRAL TEXAS, BUT WILL WAIT AND SEE THE
TRENDS WITH THE CURRENT COMPLEX OF STORMS FOR ANOTHER HOUR OR TWO
BEFORE UPDATING THE WATCH. GFS HAS SHOWN A BIT MORE CONSISTENCY
ON THE QPF MAX FOR THE RIO GRANDE PLAINS IN PAST RUNS, BUT THE
NAM HAS PERFORMED ADMIRABLY IN OTHER RECENT RAIN EVENTS, AND ITS
06Z RUN FORECAST DEVIATES THE PRECIP MAX TO THE LEFT INTO THE DRT
AREA LATER THIS MORNING. THE EXPIRATION OF THE NEW WATCH PRODUCT
WILL LIKELY BE THE SAME 02Z THAT WAS PREVIOUSLY ISSUED. MID TO
UPPER LEVEL TROUGHING OVER OKLAHOMA IS SHOWING A MORE PROGRESSIVE
TREND THAT SHOULD HELP BREAK UP THE PACIFIC MOISTURE TAP AND
REDUCE THE HEAVY RAIN THREAT. LOW-LEVEL MOISTURE WILL REMAIN
PLENTIFUL, SO WILL CONTINUE WITH SCATTERED CONVECTION TONIGHT, BUT
WITHOUT THE LOCALLY HEAVY RAINFALL MENTION.

MODEL CONSENSU FORECASTS STILL LOOK A TAD TOO OPTIMISTIC ON
DECREASING RAIN CHANCES HEADING INTO THE WORK WEEK. PRECIPITABLE
WATER FORECASTS REMAIN AT OR ABOVE NORMAL MOST OF THIS WEEK AND A
WEAK MID-LEVEL SHEAR AXIS REMAINS OVER CENTRAL TEXAS TO SUPPORT AT
LEAST SOME DIURNAL CONVECTION. THUS HAVE LEANED SLIGHTLY WETTER
THAN THE MEDIUM RANGE GUIDANCE, BUT OTHERWISE HAVE GIVEN IN TO THE
PERSISTENT TREND OF A RETURN TO SEASONAL WEATHER. THE NEXT FEW
AFTERNOONS SHOULD BE A FEW DEGREES BELOW GFS GUIDANCE HIGHS BEFORE
THE ATMOSPERE HAS A CHANCE TO AIR OUT. THE BEST CHANCE FOR AREA-
WIDE STABLE WEATHER LOOKS TO BE THURSDAY AS THE WRN US UPPER RIDGE
NUDGES EAST. BY FRIDAY, SOME OF THE MODEL DATA PUSHES A NW FLOW
EVENT INTO CENTRAL TX, BUT DOES NOT SUGGEST A HEAVY RAINFALL
PATTERN.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              89  73  90  75  92 /  50  30  30  10  20
AUSTIN BERGSTROM INTL AIRPORT  89  71  91  74  91 /  50  30  30  10  20
DEL RIO INTL AIRPORT           92  76  96  77  97 /  40  20  10  10  10
SAN ANTONIO INTL AIRPORT       88  74  90  74  91 /  50  30  20  10  20

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
ATASCOSA...BASTROP...BEXAR...CALDWELL...DE WITT...DIMMIT...
FAYETTE...FRIO...GONZALES...GUADALUPE...KARNES...LAVACA...LEE...
MEDINA...WILSON...ZAVALA.

&&

18/09