Flash Flood Warning 31, NWS Houston/Galveston, TX

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
950 PM CDT FRI SEP 6 2002

MAIN ISSUE TONIGHT CONCERNS VERY HVY RAINFALL AS STRONG CONVECTION
MOVES ONSHORE AND TRAINING OCCURS ALONG THE COAST. RAINFALL RATES
WITH THE STRONG TSTMS/BANDS WILL BE IN THE 4 INCH AN HOUR RANGE
ALONG THE COAST. FURTHER INLAND... RAINFALL NOT EXPECTED TO BE AS
HVY TONIGHT AS ALONG THE COAST...BUT TOTALS WILL GRADUALLY ADD
UP AS CONTINUOUS RAIN LIKELY IN MANY LOCATIONS. NO CHANGES TO
CURRENT FLASH FLOOD WATCH. ISOLATED TORNADOES ARE ALSO A POSSIBILITY
TONIGHT...ESPECIALLY ALONG THE COAST.

MOST OF THESE ISSUES ARE NOT REALLY AN UPDATE ISSUE AS CURRENT ZONES
HAVE HVY RAIN AND TORNADO THREAT WELL COVERED. CHANGES FOR THE
UPDATE WILL CONCERN TWEAKING THE WINDS TO BE CLOSE TO THE LATEST NHC
TRACK AND POSSIBLY MAKING SOME CHANGES TO POPS TO ACCOUNT FOR THE
LATEST TRENDS.

.HGX...TROPICAL STORM WARNING AND HURRICANE WATCH
           PORT OCONNOR TO HIGH ISLAND.
       FLASH FLOOD WATCH THROUGH SATURDAY ALL BUT FAR NE ZONES.
       INLAND TROPICAL STORM WIND WARNING WEST CENTRAL ZONES.
       TORNADO WATCH SOUTHEAST PORTIONS.

33/41/43/30

PREVIOUS DISCUSSION...
21Z UPDATE ON TROPICAL STORM FAY HAS CENTER AT 27.8 NORTH...94.8
WEST AND NEARLY STATIONARY. OFFICIAL TPC FCST TRACK HAS FAY MAKING
LANDFALL NEAR MATAGORDA BAY AROUND MIDDAY SATURDAY. OUTFLOW HAS
IMPROVED OVER WEST SIDE OF THE STORM AND LOWEST PRESSURE HAS DROPPED
TO 999 MB SO THERE IS SOME POTENTIAL FAY COULD BECOME A CAT 1
HURRICANE PRIOR TO LANDFALL.

FORECAST FOR NEAR TERM PERIODS WILL AGAIN BE TAILORED AROUND TPC
TRACK FCST. EXPECT HEAVY RAIN SHIELD TO SPREAD INLAND INTO CENTRAL
ZONES THIS EVENING...WITH HEAVIEST RAINS SHIFTING TO WESTERN HALF OF
THE AREA BY LATE SAT/SAT NIGHT. FOR TONIGHT...EXPECTING 3 TO 6
INCHES OF RAINFALL COASTAL COUNTIES...WITH 1 TO 3 INCHES CENTRAL
ZONES. FOR STORM TOTAL ACCUMULATIONS: CURRENT THINKING IS WIDESPREAD
4 TO 8 INCH ACCUMULATIONS WITH ISOLATED TOTALS OF 12 TO 15 INCHES
MAINLY OVER THE SOUTHWEST PORTION OF CWA. WILL EXTEND FFA THROUGH
SATURDAY AND KEEP SAME CONFIGURATION SOUTH OF A SHEPHERD TO
MADISONVILLE LINE. BASED ON CURRENT FCST TRACK...TROPICAL STORM
FORCE WINDS WILL REACH WHARTON/FT. BEND COUNTIES BY 12Z SO WILL
UPGRADE NPW TO INLAND TROPICAL STORM WIND WARNING FOR WEST CENTRAL
ZONES. ISOLATED TORNADOES WILL BECOME A THREAT LATE TONIGHT/SATURDAY
MAINLY SOUTH OF I-10. ALREADY HAVE SPS OUT TO HANDLE THIS SITUATION.
NEXT HURRICANE LOCAL STATEMENT WITH SPECIFIC INFORMATION ON
TIDES...FORECAST WINDS...AND EVACUATIONS WILL BE ISSUED AROUND 5 PM.

LATER PERIODS (SUNDAY ONWARD)...

AVN/CANADIAN/ECMWF IN GOOD AGREEMENT ON MOVEMENT OF FAY ONCE IT
COMES INLAND SATURDAY. SYSTEM SHOULD PUSH SLOWLY WESTWARD AND STALL
OVER SOUTH CENTRAL TEXAS AS IT BUMPS INTO MID LEVEL RIDGE. EVEN
AFTER DEPARTURE OF SYSTEM...CWA WILL LIE IN LARGE PLUME OF TROPICAL
MOISTURE (PWS 2.1 TO 2.3 INCHES) CURRENTLY STRETCHING FROM THE STORM
EASTWARD TO NRN CARIBBEAN. 12Z AVN SHOWS STRONG CONVERGENCE FROM SFC
TO 850 MB ACROSS AREA SUN/MON WHICH COULD HELP FOCUS CONVECTION. AS
A RESULT...HEAVY RAIN AND FLOODING THREAT WILL PERSIST ACROSS CWA
THROUGH AT LEAST MONDAY...AND WILL GO LIKELY POPS ALL AREAS SUN/MON.

SAVING GRACE BY MIDWEEK MAY BE EARLY SEASON COLD FRONT BEING PROGGED
BY AVN/ECMWF TO CROSS CWA TUESDAY. AVN SHOWS SIGNIFICANT DRYING
ACROSS CWA TUE-WED (PWS DROPPING BELOW 1.5 INCHES). NOT READY TO
JUMP ON THIS YET BUT WILL WORD CHANCE POPS FOR TUE/WED...DECREASING
TO SLIGHT CHANCE THU/FRI.

35/42/43/47/30

PRELIMS...
CLL TT 073/084 074/086 073 488 NE ZONES 466
IAH TT 074/082 075/086 074 ++7
GLS TT 076/082 077/084 077 ++7

TXZ200-210>214-226-227-235>238-071300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1145 PM CDT FRI SEP 6 2002

...A TORNADO WATCH HAS BEEN EXTENDED UNTIL 8 AM CDT FOR PORTIONS OF
SOUTHEAST TEXAS...

A TORNADO WATCH IS IN EFFECT UNTIL 8 AM CDT FOR JACKSON...
MATAGORDA...BRAZORIA...GALVESTON...CHAMBERS...LIBERTY...HARRIS...
...FORT BEND...WALLER...AUSTIN...COLORADO AND WHARTON COUNTIES.

RAINBANDS ASSOCIATED WITH TROPICAL STORM FAY WILL MOVE INLAND
OVERNIGHT ALONG THE SOUTHEAST TEXAS COAST. ISOLATED TORNADOES ARE
POSSIBLE AS THESE RAINBANDS MOVE ONSHORE. THE TORNADOES ARE LIKELY TO
BE EMBEDDED WITHIN THE HEAVY RAIN AREAS. STRONG...DAMAGING WIND GUSTS
ARE ALSO POSSIBLE AS RAINBANDS MOVE ONSHORE.

REMEMBER A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES
AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. RESIDENTS
SHOULD BE ON ALERT FOR TORNADO WARNINGS TONIGHT.

STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL TELEVISION OR RADIO
STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR LATER STATEMENTS
CONCERNING THIS POTENTIALLY DANGEROUS SEVERE WEATHER THREAT.