Alert archive / Texas / Flash Flood Warnings in 2001

Flash Flood Warning 68, NWS Houston/Galveston, TX

August 31, 2001Brazoria County, Fort Bend County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Aug 31, 2001, 9:55 AM CDT for Brazoria County, Fort Bend 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 the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Aug 31, 2001, 9:55 AM CDT (14:55 UTC)
Expired
Aug 31, 2001, 1:00 PM CDT
In force
3 hr
Issued by
NWS Houston/Galveston, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Brazoria County, TX, Fort Bend County, TX

The radar

The Houston radar (KHGX), 59 km from the middle of the area, began a volume at 14:57 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.9 hours before the alert went out and 250 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-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 2001-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1777 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2001-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1777 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
515 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
1.4
Supercell composite
9.7

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KHGX 311459
FFWHOU
TXC039-157-311800-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
955 AM CDT FRI AUG 31 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BRAZORIA COUNTY IN SOUTHEAST TEXAS
  FORT BEND COUNTY IN SOUTHEAST TEXAS

* UNTIL 100 PM CDT

* AT 948 AM CDT...DOPPLER RADAR INDICATED VERY HEAVY RAINFALL        
  EXTENDING FROM NEAR MISSION BEND TO IOWA COLONY TO DAMON AND TO    
  THOMPSONS. RAINFALL RATES WERE ESTIMATED AT ONE TO 
  TWO INCHES PER HOUR. MOVEMENT OF THE THUNDERSTORMS WAS NORTHEAST   
  AT 20 MPH 

* FLOODING IS EXPECTED IN OR NEAR...
  FIRST COLONY...FRESNO...HOLIDAY LAKES...MANVEL...ROSENBERG
  ...NEEDVILLE...MISSOURI CITY...ROSHARON AND WEST COLUMBIA

DO NOT CROSS ANY LOCATION WHERE WATER COVERS THE ROAD

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 2974 9576 2938 9518 2907 9570 2954 9604

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 Aug 31, 9:45 AM CDT, 10 minutes earlier.

Area forecast discussion, Aug 31, 9:45 AM CDT, 10 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
945 AM CDT FRI AUG 31 2001

MCS OVER SW THIRD OF CWFA THIS MORNING PRODUCING ISOLATED 2 INCH
PER HOUR RATES OVER WHARTON AND EXTREME SW FORT BEND COUNTIES.
SATELLITE IR LOOP INDICATE CLOUD TOP WARMING BY NEARLY 10 DEG C LAST
2 HOURS FROM THIS CLUSTER AND HOPEFULLY THIS TREND WILL CONTINUE.
HOWEVER...ANALYZED MORNING DATA SHOWS VERY HIGH PWATS (NEAR 2.5
INCHES AT KLCH) OVER REGION...DIFLUENCE AT UPPER LEVELS AND 30 KT
LLJET. WILL NOT CHANGE PREVIOUS PACKAGE SINCE IT IS ON TRACK.

37/46/48

.HGX...FFA ALL CWA TODAY.
       SCA 20 TO 60 NM HIGH ISLAND TO THE MATAGORDA SHIP CHANNEL.

CLL...080/073 083/073 088 987
IAH...079/074 080/074 086 +87
GLS...083/079 083/079 086 +87

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 7:05 PM CDTTornado WarningHGXLiberty25 min
Aug 30, 7:32 PM CDTTornado WarningHGXChambers, Galveston43 min
Aug 30, 7:49 PM CDTTornado WarningHGXBrazoria, Galveston41 min
Aug 30, 8:20 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Galveston, Harris6 hr
Aug 30, 8:25 PM CDTTornado WarningHGXChambers35 min
Aug 30, 8:45 PM CDTTornado WarningHGXBrazoria45 min
Aug 30, 9:07 PM CDTTornado WarningHGXChambers38 min
Aug 30, 9:35 PM CDTTornado WarningHGXChambers40 min
Aug 30, 10:55 PM CDTFlash Flood WarningHGXJackson, Wharton6 hr
Aug 31, 1:05 AM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Galveston, Harris6 hr
Aug 31, 3:45 AM CDTFlash Flood WarningHGXJackson, Wharton6 hr
Aug 31, 8:30 AM CDTFlash Flood WarningHGXColorado, Jackson, Matagorda, Wharton3 hr
Aug 31, 11:27 AM CDTFlash Flood WarningHGXJackson, Matagorda, Wharton3 hr
Aug 31, 1:00 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend3 hr
Aug 31, 1:52 PM CDTTornado WarningHGXChambers23 min
Aug 31, 2:28 PM CDTFlash Flood WarningHGXJackson, Wharton92 min
Aug 31, 3:55 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Jackson, Wharton2 hr
Aug 31, 5:58 PM CDTFlash Flood WarningHGXBrazoria, Fort Bend, Jackson, Wharton3 hr

Nearby

Flash Flood Warnings in Texas, 2001Every flash flood warning in 2001

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; radar from the NEXRAD Level II archive.