Alert archive / Texas / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 50, NWS Austin/San Antonio, TX

April 25, 1997Blanco County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Apr 25, 1997, 11:11 AM CDT for Blanco County, Texas. It was in force for 64 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 25, 1997, 11:11 AM CDT (16:11 UTC)
Expired
Apr 25, 1997, 12:15 PM CDT
In force
64 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Blanco County, TX

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 4.2 hours before the alert went out and 256 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, Del Rio, TX at 12:00Z on 1997-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1194 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, Del Rio, TX at 12:00Z on 1997-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 236 square meters per square second.1939587897Sfc1 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
1194 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
558 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
236 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
1.4
Supercell composite
7.2

Open this sounding in Storm Lab

The text

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

502 
WUUS1 KSAT 251613 RRA
SVRSAT
TXC031-251715-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1111 AM CDT FRI APR 25 1997
 
THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1215 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTH CENTRAL TEXAS
 
   ...BLANCO COUNTY
 
AT 1110 AM NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM WEST OF ROUND MOUNTAIN MOVING TO THE NORTHEAST AT 20 TO 25
MPH. THIS STORM WILL PASS OVER OR JUST TO THE NORTH OF ROUND MOUNTAIN IN
THE NEXT 20 MINUTES. WIND SPEEDS NEAR 50 MPH CAN BE EXPECTED WITH THIS
STORM.
 
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.
 
 
 
&

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 25, 5:39 AM CDT, 5 hours 32 minutes before
TXZ171>173-183>194-202>209-217>225-228-252300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
530 AM CDT FRI APR 25 1997

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PRODUCING LARGE
HAIL... DAMAGING WINDS AND ISOLATED TORNADOES TODAY AND TONIGHT
ACROSS ALL OF SOUTH CENTRAL TEXAS AND THE HILL COUNTRY.

AS A MAJOR STORM SYSTEM CONTINUES TO ORGANIZE OVER WEST TEXAS AND
MOVE SLOWLY SOUTH INTO MEXICO AND THE RIO GRANDE CONDITIONS WILL
BECOME INCREASINGLY FAVORABLE FOR SEVERE WEATHER AND LOCALLY HEAVY
RAINFALL TODAY AND TONIGHT.  A NUMEROUS SHOWERS AND THUNDERSTORMS
THROUGH THE PERIOD WILL PRODUCE A GENERAL 1 TO 2 INCH RAINFALL WITH
STRONGEST STORMS PRODUCING 3 INCHES OF RAIN IN A SHORT PERIOD OF
TIME.

THIS MORNING...SEVERE WEATHER WAS ONGOING OVER SOUTHWEST TEXAS.  AS
THE DEEP LOW PRESSURE SYSTEM NEAR SANDERSON MOVES SOUTH INTO
NORTHEAST MEXICO THIS MORNING...STRONG AND POSSIBLY SEVERE
THUNDERSTORMS WILL EFFECT WESTERN PORTIONS OF THE EDWARDS PLATEAU.

DURING THE AFTERNOON...TEMPERATURES WILL CLIMB INTO THE 70S AND GULF
MOISTURE WILL INCREASE AREA-WIDE IMPROVING THE RISK OF SEVERE WEATHER
ACROSS ALL OF SOUTH CENTRAL TEXAS AND THE HILL COUNTRY.  STORMS WILL
LIKELY DEVELOP OVER THE SIERRA MADRE IN MEXICO... RIO GRANDE PLAINS
OR THE HILL COUNTRY AND MOVE RAPIDLY NORTHEAST ACROSS THE AREA.

TONIGHT...THE SEVERE WEATHER PATTERN MAY EVOLVE INTO A HEAVY RAIN
EVENT.  A SLOW MOVING COLD FRONT WILL BE APPROACHING THE HILL COUNTRY
AND COULD ACT AS A FOCUS FOR ADDITIONAL HEAVY RAIN.  A FLASH FLOOD
WATCH MAY BE REQUIRED ACROSS SOME AREAS OF SOUTH TEXAS AND THE HILL
COUNTRY TONIGHT.

THE DANGER OF NIGHTTIME HEAVY RAIN EVENTS CANNOT BE OVERSTATED.
SINCE OCTOBER 1996...4 SOUTH TEXANS HAVE PERISHED IN AUTOMOBILES
DIRECTLY RELATED TO FLASH FLOODING.  ALL OF THE FATALITIES OCCURRED
WHEN AUTOMOBILES WERE SWEPT FROM THE ROADWAY BY RAGING FLOOD WATERS
IN THE DARKNESS OF NIGHT.

RESIDENTS OF SOUTH CENTRAL TEXAS...INCLUDING THE EDWARDS PLATEAU AND
HILL COUNTRY...SHOULD MONITOR THE LATEST FORECASTS AND ADVISORIES.
THIS IS A POWERFUL STORM SYSTEM PRODUCING RAPID CHANGES IN THE
WEATHER.  BE PREPARED TO MOVE TO A PLACE OF SAFETY IF SEVERE WEATHER
IS SIGHTED OR A WATCH OR WARNING IS ISSUED.

THE NATIONAL WEATHER SERVICE WILL ADVISE YOU OF THE VERY LATEST
DEVELOPING SEVERE WEATHER POTENTIAL VIA NOAA WEATHER RADIO... LOCAL
TV... CABLE TV... RADIO... AND OUR INTERNET WEBSITE LOCATED AT
WWW.SRH.NOAA.GOV.EWX

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.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 8:33 AM CDTFlash Flood WarningEWXVal Verde117 min
Apr 25, 10:20 AM CDTFlash Flood WarningEWXEdwards115 min
Apr 25, 11:17 AM CDTSevere Thunderstorm WarningEWXBurnet58 min
Apr 25, 11:52 AM CDTFlash Flood WarningEWXBlanco, Burnet, Llano4 hr
Apr 25, 1:10 PM CDTFlash Flood WarningEWXGillespie6 hr
Apr 25, 1:53 PM CDTSevere Thunderstorm WarningEWXCaldwell67 min
Apr 25, 2:30 PM CDTSevere Thunderstorm WarningEWXBexar60 min
Apr 25, 2:41 PM CDTFlash Flood WarningEWXBastrop, Caldwell4 hr
Apr 25, 2:47 PM CDTFlash Flood WarningEWXTravis, Williamson4 hr
Apr 25, 3:24 PM CDTFlash Flood WarningEWXFayette4 hr
Apr 25, 3:59 PM CDTFlash Flood WarningEWXGonzales3 hr
Apr 25, 5:16 PM CDTFlash Flood WarningEWXLavaca3 hr

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; the sounding from the Mesonet's radiosonde archive.