Flash Flooding in Texas, August 31, 2001

Name: Flash Flooding in Texas, August 31, 2001
Start: 2001-08-31T04:00
End: 2001-08-31T13:00
Location: Texas

August 31, 2001 · NWS EWX · 6 events in 6 counties and zones

Scattered showers and thunderstorms reformed shortly after midnight again across the I-35 corridor between San Antonio, New Braunfels, and San Marcos. With soils over all counties along and east of I-35, additional rainfall of between 3 and 5 inches redeveloped flash flooding southeastward to Luling, Seguin, and Karnes City.

Where it happened

Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $130,000
Crop damage: None recorded
Events: 6

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS EWX wrote it up.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Austin/San Antonio, TX wrote its last area forecast discussion before the first event at Aug 31, 1:45 AM CST, 2 hours 15 minutes earlier.

Area forecast discussion, Aug 31, 1:45 AM CST, 2 hours 15 minutes before

SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
245 AM CDT FRI AUG 31 2001

SHORT-WAVE MOVING THROUGH SOUTHERN TEXAS GENERATING CONVECTION
MAINLY SOUTH AND EAST OF SAN ANTONIO WHILE ANOTHER SHORT-WAVE ALONG
WITH LEFT FRONT QUAD OF JET MOVING INTO WESTERN TEXAS GENERATING
CONVECTION FROM WEST-CENTRAL TEXAS INTO THE DAVIS MOUNTAINS.  SOME
DRYING NOTED WEST OF LEAD SHORT-WAVE...ALTHOUGH SATELLITE DERIVED
SOUNDINGS STILL SHOW PWS GREATER THAN 2 INCHES OVER MUCH OF THE EWX
CWA.  INTERACTIONS OF THESE SHORT-WAVES/FAVORABLE JET QUAD WITH A
LOW LEVEL JET WILL LEAD TO FURTHER DEVELOPMENT THIS MORNING SIMILAR
TO PREVIOUS MORNINGS.  WEAK INVERTED SURFACE TROUGH ACROSS SOUTH
CENTRAL TEXAS WILL FOCUS MUCH OF THE CONVECTION THERE...SO WILL GO
WITH CATEGORICAL POPS AND MAINTAIN FLASH FLOOD WATCH THERE.
ELSEWHERE...CHANCE POPS SEEM REASONABLE AND MAY DROP WATCH FOR HILL
COUNTRY DUE TO NOTED DRYING.  FORECAST HIGHS WILL UNDERCUT GUIDANCE
DUE CLOUDS AND RAIN MAINLY SOUTH CENTRAL WITH GUIDANCE OKAY
ELSEWHERE.

DIFFERENCES SHOW UP AFTER TODAY AS ETA SHIFTS SURFACE TROUGH AND
HIGH PWS TO COAST WHILE AVN INDICATES ONLY A LITTLE MOVEMENT EAST
WHICH DICTATES IF THE AXIS OF HEAVY RAINFALL SHIFTS EAST OF CWA OR
NOT.  BOTH MODELS SHOW MID AND UPPER LEVEL WEAKNESS CONTINUING OVER
TEXAS...SO WILL GO WITH A MIDDLE GROUND BETWEEN THE TWO MODELS.
THUS...CHANCE POPS EAST TO LOW CHANCE/SLIGHT CHANCE POPS WEST.
CURRENT WATER VAPOR IMAGERY SUGGESTS SOME MOISTURE FROM EASTERN
PACIFIC TROPICAL STORM FLOSSIE WILL TRY TO MOVE ACROSS SOUTHERN TEXAS
BY SATURDAY.  TEMPERATURE GUIDANCE SEEMS REASONABLE...ALTHOUGH WILL
UNDERCUT HIGHS EAST DUE MAINLY RESIDUAL GROUND MOISTURE.

REMAINDER OF THE LABOR DAY WEEKEND INTO MIDDLE OF NEXT WEEK...THE
WEAKNESS REMAINS IN THE MID AND UPPER LEVELS.  SOME MODELS STILL
ADVERTISE A FEW WEAK BOUNDARIES TRYING TO WORK INTO THE CWA.  AS A
RESULT...WILL MAINTAIN AT LEAST SLIGHT CHANCE POPS THROUGH THURSDAY.

.PRELIMS...
AUS 082 072 087 073 090 94433
DRT 092 076 092 076 094 42322
SAT 082 072 087 073 090 94433

.EWX...FLASH FLOOD WATCH TODAY...SOUTH CENTRAL TEXAS AND ADJACENT
        HILL COUNTRY.

04/06/JB

In the hours before

Local storm report, Aug 31, 2:30 AM CST, 1 hour 30 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO, TX
330 AM CDT FRI AUG 31 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0405 PM    AUSTIN                    TX   FLASH FLOODING
08/27/01   TRAVIS                         WATER IN APARTMENT NEAR
                                          WALLER CREEK REPORTED
                                          BY EMC

0705 PM    SOUTHEAST OF KENEDY       TX   FLASH FLOODING
08/29/01   KARNES                         WATER COVERS HWY 239
                                          REPORTED BY LAW ENFORCEMENT

1230 PM    SEGUIN                    TX   FLASH FLOODING
08/30/01   GUADALUPE                      CITY STREETS FLOODED, WATER
                                          BEGINNING TO FLOW OVER
                                          HWY 123 SOUTH OF SEGUIN
                                          REPORTED BY LAW ENFORCEMENT

1255 PM    STOCKDALE                 TX   FLASH FLOODING
08/30/01   WILSON                         PULLING PEOPLE OUT OF HOMES
                                          REPORTED BY EMC

0300 PM    COUPLAND                  TX   FLASH FLOODING
08/30/01   WILLIAMSON                     COUNTY ROADS FLOODING
                                          6 MILES SOUTHEAST OF
                                          COUPLAND

0200 PM    SAN ANTONIO               TX   FLASH FLOODING
08/30/01   BEXAR                          3 FEET DEEP WATER FLOWING
                                          OVER WEST AVE AND LOOP 410
                                          ACCESS REPORTED BY NWS
                                          METEOROLOGIST

0700 PM    PLEASANTON                TX   FLASH FLOODING
08/30/01   ATASCOSA                       LOW WATER CROSSINGS IN FLOOD
                                          ALONG ATASCOSA RIVER REPORTED
                                          BY LAW ENFORCEMENT

0925 PM    COUNTY WIDE               TX   FLASH FLOODING
08/30/91   UVALDE                         SOME FARM ROADS UNDER WATER
                                          REPORTED BY LAW ENFORCEMENT

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

6 flash flood. Local standard time, as filed.

Flash Flood, Bexar

When: August 31, 4:00 AM CST to 8:30 AM CST
Where: Bexar County, Countywide
Property damage: $30,000
Reported by: EMERGENCY MANAGER
Coordinates: 29.449, -98.520 (the zone’s center; the record gives no point)

Flash Flood, Comal

When: August 31, 4:00 AM CST to 8:00 AM CST
Where: Comal County, Countywide
Property damage: $20,000
Reported by: LAW ENFORCEMENT
Coordinates: 29.808, -98.278 (the zone’s center; the record gives no point)

Flash Flood, Guadalupe

When: August 31, 4:00 AM CST to 8:00 AM CST
Where: Guadalupe County, Countywide
Property damage: $20,000
Reported by: AMATEUR RADIO
Coordinates: 29.583, -97.949 (the zone’s center; the record gives no point)

Flash Flood, Hays

When: August 31, 4:00 AM CST to 8:00 AM CST
Where: Hays County, Countywide
Property damage: $20,000
Reported by: LAW ENFORCEMENT
Coordinates: 30.058, -98.031 (the zone’s center; the record gives no point)

Flash Flood, Caldwell

When: August 31, 4:30 AM CST to 8:30 AM CST
Where: Caldwell County, Countywide
Property damage: $20,000
Reported by: LAW ENFORCEMENT
Coordinates: 29.837, -97.620 (the zone’s center; the record gives no point)

Flash Flood, Karnes

When: August 31, 7:00 AM CST to 1:00 PM CST
Where: Karnes County, Countywide
Property damage: $20,000
Reported by: LAW ENFORCEMENT
Coordinates: 28.906, -97.859 (the zone’s center; the record gives no point)

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Texas in 2001 Every state in 2001 This day in weather history Warnings in Texas, August 2001

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5260995, 5260996, 5260997, 5260998, 5260999, 5261063.