Tropical Storm in Texas, September 1 to 2, 2003

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
830 PM CDT SUN AUG 31 2003

CIRCULATION CENTER ASSOCIATED WITH TD GRACE LOCATED OVER NRN BRAZOS
COUNTY AT 01Z AND PUSHING NWD. ETA MODEL APPEARS TO HAVE BEST HANDLE
ON THE SYSTEM IN THE SHORT TERM AND WILL GENERALLY FOLLOW IT FOR
FCST. 00Z LCH SOUNDING SHOWS PW OF 2.43 INCHES WITH K-INDEX OF 40 ON
CRP SOUNDING. MODELS SHOW 30 KT LLJ DEVELOPING OVERNIGHT WHICH WILL
CONTINUE TO TRANSPORT HIGH PW AIR ACROSS CWA.

MAIN FCST CHALLENGE IS POTENTIAL FOR HEAVY RAINFALL AND FFA
CONFIGURATION OVERNIGHT. PRIMARY CONCERN FOCUSES ON TWO AREAS. FIRST
AREA OVER THE NWRN ZONES WHERE CORE RAINS COULD DEVELOP OVERNIGHT
NEAR CENTER OF GRACE. GOOD NEWS FOR OUR AREA IS GRACE CONTINUES
STEADILY MOVING NORTHWARD WHICH COULD HELP FOCUS THE HEAVIEST OF
THESE RAINS NORTH OF THE CWA. SECOND AREA OF CONCERN IS OVER WRN
COUNTIES WHERE MESOSCALE OUTFLOW BOUNDARY (NOW OVER SC TX) COULD
COMBINE WITH MOISTURE TRANSPORT FROM LLJ TO FOCUS HEAVY TSRA
OVERNIGHT. LATEST ETA HINTS AT THIS SHOWING HIGHER QPF WRN 1/3 OF
CWA AFTER MIDNIGHT. REST OF SE TX WILL SEE BANDS OF SCATTERED
CONVECTION BUT SHORT DURATION AND QUICK MOVEMENT SHOULD PRECLUDE A
SIGNIFICANT FLOODING THREAT. WILL LOWER FFA FOR TWO TIERS OF
COUNTIES CLOSEST TO COAST...BUT KEEP IT GOING NORTH OF A COLUMBUS TO
CONROE TO LIVINGSTON LINE. WILL ALSO LOWER POPS SE HALF OF THE AREA.

MARINE...SEAS STILL BORDERLINE SCA CRITERIA OVER WATERS BUT WINDS
HAVE DROPPED OFF SIGNIFICANTLY. WILL LIKELY LOWER SCA TO SCEC DURING
THE 1030 PM UPDATE.

35/43/38

.HGX...FLOOD WATCH NORTH OF COLUMBUS-CONROE-LIVINGSTON LINE THRU MON.
       SCA HIGH ISLAND TO MATAGORDA SHIP CHANNEL OUT 60 NM

PRELIMS...
CLL TT 075/084 072/089 072 885
IAH TE 075/085 074/090 073 664
GLS TE 079/086 078/088 079 454

THE REMAINS OF GRACE DRIFTING NORTHWEST ACROSS HARRIS COUNTY...
CIRCULATION CLEARLY DEPICTED SW OF TOMBALL AT 18Z. VERY HEAVY RAINS
HAVE BEEN FALLING ALONG THE FEEDER BAND FROM 60NM SOUTH OF GALVESTON
TO THE BOLIVAR PENINSULA TO NEAR LIVINGSTON. SHERIFFS REPORTING TRAVEL
ALONG BOLIVAR DIFFICULT DUE TO WATER ON ROADS. WILL LIKELY GET A BRIEF
LULL IN CONVECTION INLAND THROUGH MID AFTERNOON OVER THE
CENTRAL/NORTHWEST ZONES. 12Z MODELS DIDNT GRASP THE INLAND SURFACE
CIRCULATION AT ALL...AND HAVE FOCUSED ON THE BAGGINESS ALONG THE
INVERTED TROUGH. LARGE CLUSTER OF CONVECTION WELL SOUTH IN THE WEST-
CENTRAL GULF NEAR 25.7N/94.5W...MAY SHUT DOWN THE TROPICAL TAP
SOMEWHAT ON MONDAY. SWELLS OF 5 TO 9 FEET CONTINUE THIS AFTERNOON AND
SHOULD BE SUBSIDING...PLANNING TO LEAVE SCA 0-60NM.

WILL MORE OR LESS IGNORE THE LOW LEVEL PROGS AND GO WITH THE
CIRCULATION DRIFTING TO NEAR COLLEGE STATION 00-03Z AND THEN ON
NORTHWEST MORE SLOWLY. (THANKS HPC/EWX FOR COLLABORATION) DIFFLUENCE
ALOFT AND STRONG MOISTURE TRANSPORT DOWN LOW SHOULD SHIFT WEST AROUND
6Z AND BE INTO BRAZORIA/FORT BEND REGION WRAPPING NORTHWARD INTO THE
CENTER WITH A CORE EVENT TRYING TO GET ORGANIZED. QPF OF 2 TO 5 INCHES
WITH ISOLATED AMOUNTS OF 7 TO 8 INCHES SEEMS IN ORDER THROUGH 12Z
MONDAY MAINLY ALONG THE IMMEDIATE COAST AND THEN CLOSER TO THE CENTER
IN MONTGOMERY/WALKER/TRINITY/HOUSTON/MADISON/BRAZOS/GRIMES COUNTIES.
WILL OBVIOUSLY KEEP THE FLOOD WATCH UP. A LITTLE MORE IFFY MONDAY AS
FOCUS FOR PRECIP SHOULD BE OUT OF THE AREA THOUGH STRONG MOISTURE
TRANSPORT STILL GOING OVER THE CWA AND DAYTIME HEATING COULD GET
SHRA/TSRA TO BLOW UP OVER THE AREA AND BE A NEARLY FIXED...TRAINING
NORTH. MODELS STILL ADVERTISING A COLD FRONT TO MOVE SOUTH AND TO GET
NEAR THE COLLEGE STATION AREA 12Z TUESDAY AND AM HAVING A REALLY HARD
TIME BELIEVING THIS SCENARIO. WILL LIKELY HOLD OFF WITH IT KEEPING IT
NORTH OF THE FA THROUGH AT LEAST THURSDAY...THE AIRMASS THAT IS TRYING
TO PUSH THE BOUNDARY SOUTH IS PACIFIC IN NATURE AND AFTER CROSSING THE
ROCKIES IS NOT LIKELY TO HAVE MUCH PUSH LEFT.

45/37/47/DH

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-011100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
700 AM CDT SUN AUG 31 2003

...TROPICAL STORM WARNING IN EFFECT FROM HIGH ISLAND TO MATAGORDA
BAY...
...FLOOD WATCH IN EFFECT FOR ALL OF SOUTHEAST TEXAS THROUGH
TONIGHT...
...LOCALLY HEAVY RAINFALL POSSIBLE THROUGH TONIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT.
A TROPICAL STORM WARNING REMAINS IN EFFECT THIS MORNING FROM HIGH
ISLAND TO MATAGORDA BAY. WEAK AND POORLY ORGANIZED TROPICAL STORM
GRACE IS EXPECTED TO MOVE INLAND ALONG THE MIDDLE TEXAS COAST LATER
TODAY. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
PERSIST ACROSS PORTIONS OF SOUTHEAST TEXAS TODAY AND TONIGHT AS
INFLOW OFF THE GULF CONTINUES. RAINFALL TOTALS THROUGH MIDNIGHT
TONIGHT ARE EXPECTED TO AVERAGE AS HIGH AS 6 TO 8 INCHES WITH
ISOLATED 8 TO 12 INCH AMOUNTS POSSIBLE WHERE THE BEST TRAINING
DEVELOPS. PLEASE REFER TO HLSHOU AND FFAHGX FOR MORE DETAILS
REGARDING THIS ONGOING FLOOD THREAT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.
THE THREAT FOR LOCALLY HEAVY RAINFALL IS EXPECTED TO GRADUALLY SHIFT
TO THE WEST ON MONDAY AFTERNOON. WESTERN PORTIONS OF SOUTHEAST TEXAS
MAY EXPERIENCE THE GREATEST THREAT FOR LOCALLY HEAVY RAINFALL. THESE
SAME WESTERN COUNTIES MAY CONTINUE TO BE UNDER THE GUN FOR HEAVY
RAINFALL ON TUESDAY AND WEDNESDAY AS THE REMNANTS OF GRACE MOVE
SLOWLY IN AND AROUND THE TEXAS HILL COUNTRY. SLIGHTLY DRIER AIR
MIGHT FINALLY ENTER THE FORECAST AREA FROM THE NORTH TOWARD THE END
OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...
EMERGENCY MANAGERS AND STORM SPOTTERS SHOULD BE PREPARED FOR
ACTIVATION. PREPAREDNESS PLANS SHOULD BE IMPLEMENTED.