Alert archive / Texas / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 46, NWS Austin/San Antonio, TX

April 20, 1997Williamson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Apr 20, 1997, 9:31 PM CDT for Williamson County, Texas. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 20, 1997, 9:31 PM CDT (02:31 UTC)
Expired
Apr 20, 1997, 10:15 PM CDT
In force
44 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Williamson County, TX

What was reported inside it

TimeReportWhereRemark
Apr 20, 10:00 PM CDTHail 0.75Hutto, TX

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.5 hours before the alert went out and 245 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, Fort Worth, TX at 00:00Z on 1997-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 406 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 1997-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.193958Sfc1 km3 km6 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
406 J/kg
Mixed-layer CIN
-150 J/kg
Mixed-layer LCL
1725 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
277 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

362 
WUUS1 KSAT 210233 RRA
SVRSAT
TXC491-210315-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
931 PM CDT SUN APR 20 1997
 
THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1015 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTH CENTRAL TEXAS
 
   ...WILLIAMSON COUNTY
 
AT 934 PM CDT WEATHER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
WITH DAMAGING WIND MOVING THROUGH WILLIAMSON COUNTY. SOME WIND DAMAGE
HAS BEEN REPORTED IN LIBERTY HILL.
 
SEVERE THUNDERSTORM WINDS CAN REACH SPEEDS OVER 60 MPH.  THESE WINDS
BLOW DOWN TREES...POWER LINES...AND SEVERELY DAMAGE MOBILE HOMES...
SOMETIMES BUILDINGS.  VERY LARGE HAIL CAN INJURE ANYONE CAUGHT
OUTSIDE.
 
REPORT INCIDENTS OF SEVERE WEATHER TO LOCAL LAW ENFORCEMENT.
 
 
&

What forecasters said that day

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

In the hours before

Special weather statement, Apr 20, 5:35 PM CDT, 3 hours 56 minutes before
TXZ171>173-183>194-202>209-217>225-228-211200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
535 PM CDT SUN APR 20 1997

THE STORM PREDICTION CENTER IN NORMAN OK HAS ISSUED A SEVERE
THUNDERSTORM WATCH FOR THE ENTIRE TEXAS HILL COUNTRY AND ADJOINING
PORTIONS OF SOUTH CENTRAL TEXAS.

A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR THE
DEVELOPMENT OF SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGINGS
WINDS.

THE WATCH IS ALONG AND NORTH OF A LINE FROM DEL RIO TO UVALDE...
HONDO... SAN ANTONIO... NEW BRAUNFELS... SAN MARCOS... AUSTIN... AND
GEORGETOWN.

THE ATMOSPHERE HAS BECOME VERY UNSTABLE WITH INCREASING HUMIDITY AND
WARM TEMPERATURES ACROSS SOUTH AND CENTRAL TEXAS.  A WEAK UPPER LEVEL
DISTURBANCE WILL MOVE THROUGH CENTRAL TEXAS THIS EVENING.
THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THE DISTURBANCE.

THE HAZARDOUS WEATHER OUTLOOK WILL NORMALLY BE UPDATED BY MEANS OF
THE ZONE FORECAST...SHORT TERM FORECASTS...WATCHES....WARNINGS AND
ADVISORIES.  THE HAZARDOUS WEATHER OUTLOOK ITSELF WILL BE UPDATED
ONLY IF UNFORECAST HAZARDOUS WEATHER DEVELOPS OR IF FORECAST
HAZARDOUS WEATHER IS NO LONGER EXPECTED.
Special weather statement, Apr 20, 5:44 PM CDT, 3 hours 47 minutes before
TXZ171>173-183>194-202>209-217>225-228-211200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
535 PM CDT SUN APR 20 1997

THE STORM PREDICTION CENTER IN NORMAN OK HAS ISSUED A SEVERE
THUNDERSTORM WATCH FOR THE ENTIRE TEXAS HILL COUNTRY AND ADJOINING
PORTIONS OF SOUTH CENTRAL TEXAS.

A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR THE
DEVELOPMENT OF SEVERE THUNDERSTORMS WITH LARGE HAIL AND DAMAGINGS
WINDS.

THE WATCH IS ALONG AND NORTH OF A LINE FROM DEL RIO TO UVALDE...
HONDO... SAN ANTONIO... NEW BRAUNFELS... SAN MARCOS... AUSTIN... AND
GEORGETOWN.

THE ATMOSPHERE HAS BECOME VERY UNSTABLE WITH INCREASING HUMIDITY AND
WARM TEMPERATURES ACROSS SOUTH AND CENTRAL TEXAS.  A WEAK UPPER LEVEL
DISTURBANCE WILL MOVE THROUGH CENTRAL TEXAS THIS EVENING.
THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THE DISTURBANCE.

THE HAZARDOUS WEATHER OUTLOOK WILL NORMALLY BE UPDATED BY MEANS OF
THE ZONE FORECAbST...SHORT TERM FORECASTS...WATCHES....WARNINGS AND
ADVISORIES.  THE HAZARDOUS WEATHER OUTLOOK ITSELF WILL BE UPDATED
ONLY IF UNFORECAST HAZARDOUS WEATHER DEVELOPS OR IF FORECAST
HAZARDOUS WEATHER IS NO LONGER EXPECTED.
Special weather statement, Apr 20, 9:19 PM CDT, 12 minutes before
TXZ171>173-183>194-202>209-217>225-228-210500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
919 PM CDT SUN APR 20 1997

THE THREAT OF SEVERE WEATHER HAS ENDED ACROSS THE FOLLOWING
COUNTIES... VAL VERDE... KINNEY... REAL... UVALDE... EDWARDS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR THE TEXAS HILL
COUNTRY AND PORTIONS OF SOUTH CENTRAL TEXAS NORTH OF A LINE FROM
HONDO TO SAN ANTONIO... NEW BRAUNFELS... SAN MARCOS... AUSTIN... AND
GEORGETOWN INCLUDING BANDERA AND KERRVILLE.
Special weather statement, Apr 20, 9:26 PM CDT, 5 minutes before
TXZ171>173-183>194-202>209-217>225-228-210500-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
919 PM CDT SUN APR 20 1997

THE THREAT OF SEVERE WEATHER HAS ENDED ACROSS THE FOLLOWING
COUNTIES... VAL VERDE... KINNEY... REAL... UVALDE... EDWARDS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR THE TEXAS HILL
COUNTRY AND PORTIONS OF SOUTH CENTRAL TEXAS NORTH OF A LINE FROM
HONDO TO SAN ANTONIO... NEW BRAUNFELS... SAN MARCOS... AUSTIN... AND
GEORGETOWN INCLUDING BANDERA AND KERRVILLE.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 8:07 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano53 min
Apr 20, 8:57 PM CDTSevere Thunderstorm WarningEWXBlanco, Comal, Hays, Kendall63 min
Apr 20, 9:17 PM CDTSevere Thunderstorm WarningEWXTravis58 min
Apr 20, 10:14 PM CDTSevere Thunderstorm WarningEWXGuadalupe46 min
Apr 20, 11:17 PM CDTSevere Thunderstorm WarningEWXLavaca43 min
Apr 21, 3:47 AM CDTSevere Thunderstorm WarningEWXBastrop, Travis, Williamson58 min

Nearby

Severe Thunderstorm Warnings in Texas, 1997Every severe thunderstorm warning in 1997

Sources

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