Alert archive / Texas / Flash Flood Warnings in 2003

Flash Flood Warning 19, NWS Houston/Galveston, TX

September 1, 2003Brazoria County, Matagorda County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Sep 1, 2003, 3:35 AM CDT for Brazoria County, Matagorda County, Texas. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Sep 1, 2003, 3:35 AM CDT (08:35 UTC)
Expired: Sep 1, 2003, 6:30 AM CDT
In force: 3 hr
Issued by: NWS Houston/Galveston, TX
Area: Counties, with a storm outline in the text

Counties Brazoria County, TX, Matagorda County, TX

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 8.6 hours before the alert went out and 219 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 2085 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1057 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS54 KHGX 010838
FFWHOU
TXC039-321-011130-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
335 AM CDT MON SEP 1 2003

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BRAZORIA COUNTY IN SOUTHEAST TEXAS
  MATAGORDA COUNTY IN SOUTHEAST TEXAS

* UNTIL 630 AM CDT

* AT 330 AM CDT...DOPPLER RADAR INDICATED VERY HEAVY RAINFALL ACROSS 
SOUTHERN PORTIONS OF MATAGORDA AND BRAZORIA COUNTIES. RADAR HAS 
ESTIMATED UP TO 5 INCHES OF RAIN SINCE MIDNIGHT JUST NORTH OF MATAGORDA.

* FLOODING IS EXPECTED MAINLY ALONG AND SOUTH OF HIGHWAY 35 IN BOTH 
MATAGORDA AND BRAZORIA COUNTIES BUT COULD SPREAD FURTHER INLAND AS 
MORE RAIN DEVELOPS.

DO NOT CROSS ANY LOCATION WHERE WATER COVERS THE ROAD

USE EXTRA CAUTION AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DEPTH
AND SPEED OF FLASH FLOOD WATERS.

PLEASE REPORT FLOODING TO THE COUNTY SHERIFF...LOCAL POLICE...OR
DEPARTMENT OF PUBLIC SAFETY. THEY WILL RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

LAT...LON 2925 9507 2904 9518 2876 9556 2850 9620
          2864 9629 2897 9633 2951 9525

$$

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this flash flood warning went out at Sep 1, 1:44 AM CDT, 1 hour 51 minutes earlier.

Area forecast discussion, Sep 1, 1:44 AM CDT, 1 hour 51 minutes before

SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
144 AM CDT MON SEP 1 2003

HAVE DECIDED TO GO AHEAD AND EXTEND THE FLOOD WATCH BACK DOWN TO THE
COAST DUE TO THE CURRENT FLARE UP (SEE FFAHGX). SOME LOCATIONS
ACROSS OUR UPPER TEXAS COASTAL COUNTIES RECEIVED BETWEEN 4 AND 12
INCHES OF RAIN YESTERDAY...AND IT WILL NOT TAKE A WHOLE LOT MORE TO
LEAD TO FLOODING. THE FLOOD WATCH IS IN EFFECT FOR TODAY FOR ALL OF
SOUTHEAST TEXAS. THANKS LCH FOR COORDINATION.

42/46

.HGX...FLOOD WATCH ALL OF SOUTHEAST TEXAS TODAY.
       SCEC 00-60 NM WATERS.

UPDATED PRELIMS...
CLL TT 075/084 072/089 072 685
IAH TE 075/085 074/090 073 664
GLS TE 079/086 078/088 079 854
---------------------------------------------------------------------

.PREVIOUS DISCUSSION (114 AM)...
DID A ZONE UPDATE TO RAISE COASTAL COUNTY POPS AND MAKE A COUPLE
OTHER 1ST PERIOD ADJUSTMENTS. MONITORING DEVELOPING CONVECTION ACROSS
THE COASTAL COUNTIES AND OVER THE ADJACENT COASTAL WATERS. FAST
STORM MOTION IS KEEPING RAINFALL TOTALS SO FAR ON THE LIGHT SIDE...
BUT WILL HAVE TO WATCH IF SIGNIFICANT TRAINING DEVELOPS. MAY NEED TO
RECONFIGURE THE FLOOD WATCH A LITTLE FURTHER SOUTH AND EAST IF THESE
STORMS PERSIST OR INCREASE IN COVERAGE. A COASTAL WATERS FORECAST
UPDATE WAS ALSO MADE.   42/46

Hazardous weather outlook, Aug 31, 7:00 AM CDT, 20 hours 35 minutes before

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.

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 1, 4:21 AM CDT	Special Marine Warning	HGX		114 min
Sep 1, 6:20 AM CDT	Flash Flood Warning	HGX	Matagorda	3 hr
Sep 1, 7:00 AM CDT	Flash Flood Warning	HGX	Chambers, Galveston	3 hr
Sep 1, 7:50 AM CDT	Flash Flood Warning	HGX	Brazoria	2 hr

Nearby

Flash Flood Warnings in Texas, 2003 Every flash flood warning in 2003

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.