Alert archive / Texas / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 49, NWS Austin/San Antonio, TX

April 21, 1997Bastrop County, Travis County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Apr 21, 1997, 3:47 AM CDT for Bastrop County, Travis County, Williamson County, Texas. It was in force for 58 min. 3 reports 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 21, 1997, 3:47 AM CDT (08:47 UTC)
Expired
Apr 21, 1997, 4:45 AM CDT
In force
58 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

Counties Bastrop County, TX, Travis County, TX, Williamson County, TX

What was reported inside it

TimeReportWhereRemark
Apr 21, 3:47 AM CDTThunderstorm Wind 62Taylor, TX
Apr 21, 3:50 AM CDTHail 0.75Round Rock, TX
Apr 21, 4:00 AM CDTHail 0.75Rockne, 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, 8.8 hours before the alert went out and 276 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°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.

000 
TTAA00 KSAT 210848 RRA
SVRSAT
TXC021-453-491-210945-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
347 AM CDT MON APR 21 1997
 
THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  445 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTH CENTRAL TEXAS
 
   ...BASTROP COUNTY...TRAVIS COUNTY...WILLIAMSON COUNTY
 
AT 345 AM DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM NEAR LEANDER
IN WILLIAMSON COUNTY. THE STORM IS MOVING SOUTHEAST AT 20 MPH AND
WILL BE IN NORTHERN PORTIONS OF THE CITY OF AUSTIN NEAR 4 AM.
 
PEOPLE IN THE PATH OF THIS STORM SHOULD BE ALERT TO THE POSSIBILITY
OF LARGE HAIL AND DAMAGING WINDS.  FREQUENT LIGHTNING AND LOCALLY
HEAVY RAIN CAN ALSO OCCUR WITH SEVERE THUNDERSTORMS...FLOODING SMALL
STREAMS...LOW AREAS...AND LOW WATER CROSSINGS.
 
IF YOU SEE SEVERE WEATHER TAKING PLACE...CALL YOUR REPORT TO
THE NEAREST LBAW ENFORCEMENT AGENCY FOR IMMEDIATE RELAY TO THE
NATIONAL WEATHER SERVICE.

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, 9:31 PM CDTSevere Thunderstorm WarningEWXWilliamson44 min
Apr 20, 10:14 PM CDTSevere Thunderstorm WarningEWXGuadalupe46 min
Apr 20, 11:17 PM CDTSevere Thunderstorm WarningEWXLavaca43 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.