Alert archive / Texas / Flash Flood Warnings in 2001

Flash Flood Warning 61, NWS Austin/San Antonio, TX

September 4, 2001DeWitt County, Lavaca County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Sep 4, 2001, 12:45 AM CDT for DeWitt County, Lavaca 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
Sep 4, 2001, 12:45 AM CDT (05:45 UTC)
Expired
Sep 4, 2001, 3:30 AM CDT
In force
3 hr
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties DeWitt County, TX, Lavaca County, TX

The radar

The Austin/San Antonio radar (KEWX), 96 km from the middle of the area, began a volume at 05:44 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

Corpus Christi, TX (KCRP), launched 00:00Z, 5.8 hours before the alert went out and 157 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, Corpus Christi, TX at 00:00Z on 2001-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2619 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 00:00Z on 2001-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 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
2619 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1035 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
1.1
Supercell composite
8.8

Open this sounding in Storm Lab

The text

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

000 
WGUS54 KEWX 040544
FFWSAT
TXC123-285-040830-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1245 AM CDT TUE SEP 4 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* FLASH FLOOD WARNING FOR THE FOLLOWING COUNTIES IN TEXAS...
  LAVACA
  DEWITT

* UNTIL 330 AM CDT

* AT 1240 AM...WEATHER SERVICE DOPPLER RADAR INDICATED HEAVY RAINS 
THROUGHOUT MUCH OF LAVACA AND DEWITT COUNTIES.  THIS AREA OF HEAVY 
RAIN WAS MOVING SOUTHEAST AT 10 TO 15 MPH.  WITH THE RECENT 
RAINS...GROUNDS REMAIN TOTALLY SATURATED...WITH RAPID RUNOFF AND 
RESULTANT FLOODING EXPECTED.
   
HEAVY RUNOFF WILL FORCE SMALL STREAMS AND CREEKS OUT OF 
BANKS...FLOODING SECONDARY ROADS...LOW BRIDGES AND CROSSINGS ACROSS 
LAVACA COUNTY THE NEXT FEW HOURS. MOTORISTS SHOULD APPROACH FLOOD 
PRONE AREAS VERY SLOWLY...AND UNDER NO CIRCUMSTANCES ENTER FLOODED 
LOW WATER CROSSINGS. 

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND
ARROYOS...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

LAT...LON 2897 9767 2887 9755 2934 9666 2956 9682

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 3, 7:13 PM CDTSevere Thunderstorm WarningEWXVal Verde77 min
Sep 3, 9:07 PM CDTFlash Flood WarningEWXVal Verde53 min
Sep 4, 3:46 PM CDTFlash Flood WarningEWXDeWitt, Karnes, Lavaca4 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.