Alert archive / Texas / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 103, NWS Austin/San Antonio, TX

May 20, 1987Val Verde County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 1987, 10:20 PM CDT for Val Verde County, Texas. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
May 20, 1987, 10:20 PM CDT (03:20 UTC)
Expired
May 20, 1987, 11:20 PM CDT
In force
60 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Val Verde County, TX

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 3.3 hours before the alert went out and 66 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 00:00Z on 1987-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2341 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 00:00Z on 1987-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 square meters per square second.193958Sfc1 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
2341 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
1554 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDRT 210328 COR
SVRDRT
TXC465-210320-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DEL RIO TX
1028 PM CDT WED MAY 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 1120 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY IN

SOUTHCENTRAL TEXAS...VAL VERDE

THE TORNADO WARNING ISSUED EARLIER FOR PERSONS IN VAL VERDE
COUNTY TX HAS EXPIRED.

A LARGE SEVERE THUNDERSTORM WAS LOCATED EAST OF DEL RIO NEAR LAUGHLIN
AFB OUT TO THE KINNY VAL VERDE COUNTY LINE. THIS SEVERE THUNDERSTORM
WAS MOVING EAST AT 20 MPH.

THIS CONTINUES TO BE A VERY DANGEROUS STORM.  AS THIS THUNDERSTORM
MOVED ACROSS THE LAKE AMISTAD AND THE CITY OF DEL RIO IT PRODUCED A
A POSSIBLE TORNADO...WINDS UP TO 73 MPH...MARBLE SIZE HAIL AND VERY
HEAVY RAIN..

PERSONS IN THE PATH OF THIS DANGEROUS THUNDERSTORM SHOULD MOVE INSIDE
A STRONG BUILDING. STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS
PASSED.

REMEMBER SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH..DESTRUCTIVE HAIL..DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICK>LY SO DONT DRIVE INTO AREAS
WHERE WATER COVERS THE ROAD.

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, May 20, 7:40 PM CDT, 2 hours 40 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN TX
740 PM CDT WED MAY 20 1987

SEVERE THUNDERSTORM ACTIVITY CONTINUES IN AND AROUND THE CITY OF SAN
ANTONIO SPREADING NORTH AND EASTWARD.

THESE SEVERE THUNDERSTORMS ARE ONLY 50 TO 60 MILES SOUTHWEST OF AUSTIN
...BUT THEY ARE EXPECTED TO DIMINISHING IN INTENSITY AFTER SUNSET
AS THEY APPROACH CALDWELL AND HAYS COUNTIES.

RESIDENTS IN HAYS AND CALDWELL COUNTIES SHOULD STAY ALERT TO THE MOVMENT
OF THESE STORMS FOR THE NEXT ONE TO TWO HOURS.
Special weather statement, May 20, 8:09 PM CDT, 2 hours 11 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN TX
805 PM CDT WED MAY 20 1987

A SEVERE THUNDERSTORM WAS LOCATED OVER THE CENTRAL PORTIONS OF COMAL
COUNTY MOVING TOWARDS THE NORTH.

THIS SEVERE THUNDERSTORM IS LOCATED ABOUT 45 MILES MILES SOUTHWEST
OF AUSTIN MOVING TOWARDS HAYS AND BLANCO COUNTIES.

RESIDENTS IN HAYS AND BLANCO COUNTIES SHOULD STAY ALERT TO THE MOVMENT
OF THIS SEVERE STORM FOR THE NEXT HOUR...FOR IF THE STORM CONTINUES/
AT ITS PRESENT INTENSITY A SEVERE THUNDESTORM WARNING
MAYBE ISSUED FOR EITHER OR BOTH HAYS AND BLANCO COUNTIES.
Special weather statement, May 20, 8:23 PM CDT, 1 hour 57 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DEL RIO TX
823 PM CDT WED MAY 20 1987

AT 820 PM CDT AN AREA OF THUNDERSTORMS COVERED MOST OF CENTRAL
VAL VERDE COUNTY AND WAS MOVING NORTHEAST AT ABOUT 10 TO 15 MPH.

VERY HEAVY THUNDERSTORMS WERE NORTHEAST OF LANGTRY.  SOUTH WINDS 20
WITH ESTIMATED GUSTS TO 40 MPH WAS REPORTED NORTH OF COMSTOCK ALONG
THE DEVILS RIVER.  THE MOST INTENSE AND DANGEROUS THUNDERSTORMS
WERE STILL LOCATED IN MEXICO ABOUT 20 MILES WEST AND SOUTHWEST OF DEL
RIO MOVING NORTHEAST TOWARD VAL VERDE COUNTY.

PERSONS LIVING IN THE PATH OF THESE THUNDERSTORMS SHOULD BE PREPARED
TO TAKE SAFETY PRECAUTIONS IF THIS STORM MOVES INTO THEIR VICINITY.

BOATERS ON LAKE AMISTAD...RIO GRANDE...PECOS AND DEVILS RIVERS SHOULD
BE AWARE OF THIS POTENTIAL DANGEROUS STORM AND CONSIDER MOVING TO A
SAFE HARBOR IF THEY HAVE NOT ALREADY DONE SO.  DANGEROUS CLOUD TO
GROUND LIGHTNING AND STRONG GUSTY SURFACE WINDS HAVE BEEN REPORTED
6OUT OF THESE THUNDERSTORMS.

HEAVY RAIN...GUSTY WINDS...SMALL HAIL AND DANGEROUS LIGHTNING ARE
QUITE LIKELY FROM THESE THUNDERSTORMS.
Local storm report, May 20, 8:28 PM CDT, 1 hour 52 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE SAN ANTONIO TX
825 PM CDT WED MAY 20 1987

TIME         EVENT

 720 PM      NUMEROUS REPORTS OF PEA AND MARBLE SIZE HAIL NORTHEAST
             SAN ANTONIO...BEXAR COUNTY
 725 PM      ESTIMATED WIND GUST TO 50 MPH JUDSON AND NACOGDOCHES ROADS
             NORTHEAST SAN ANTONIO...BEXAR COUNTY
 730 PM      POSSIBLE TORNADO INDICATED NE OF SAN ANTONIO BY RANDOLPH
             AFB RADAR...BEXAR COUNTY
 802 PM   <   HALF INCH HAIL 13MILES WEST OF NEW BRAUNFELS..COMAL COUNTY
 803 PM      LARGE HAIL AND HIGH WINDS FM 3159 SOUTH OF CANYON LAKE
             ...COMAL COUNTY
 810 PM      PEA SIZE HAIL AT CANYON LAKE...COMAL COUNTY
Special weather statement, May 20, 10:08 PM CDT, 12 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN TX
1005 PM CDT WED MAY 20 1987

THE SEVERE THUNDERSTORM WARNING ISSUED AT 927 PM FOR PERSONS IN TRAVIS
COUNTY IS NO LONGER IN EFFECT.

THIS THUNDERSTORM IS DECREASING IN INTENSITY AND MOVING INTO THE
SOUTHWEST PORTIONS OF WILLIAMSON COUNTY WITH A MOVEMENT TOWARDS
THE NORTH NORTHEAST.

AS THIS THUNDERSTORMS MOVES OVER THE CENTRAL PORTIONS OF WILLIAMSON
COUNTY IT MAY PRODUCE SMALL HAIL...BR0IEF HEAVY RAINFALL AND GUSTY WINDS.

NO DAMAGE REPORTS HAVE BEEN RECEIVED AT THE AUSTIN WEATHER
SEVERE OFFICE FROM BLANCO...HAYS OR WESTERN TRAVIS COUNTY TONIGHT.
Local storm report, May 20, 10:11 PM CDT, 9 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE SAN ANTONIO TX
1008 PM CDT WED MAY 20 1987

TIME         EVENT

 842 PM      MARBLE TO GOLF BALL SIZE HAIL...TREES BENDING HEAVILY...
             COMAL COUNTY
10011 PM      FROM DEL RIO TEXAS...WIND GUST TO 73 MPH...1 INCH RAIN...
             MARBLE SIZE HAIL...MOVING INTO KINNEY COUNTY

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 7:11 PM CDTSevere Thunderstorm WarningEWXWilson64 min
May 20, 7:38 PM CDTSevere Thunderstorm WarningEWXAtascosa, Frio67 min
May 20, 7:42 PM CDTSevere Thunderstorm WarningEWXComal63 min
May 20, 8:34 PM CDTSevere Thunderstorm WarningEWXBlanco, Hays56 min
May 20, 8:50 PM CDTSevere Thunderstorm WarningEWXVal Verde56 min
May 20, 8:56 PM CDTSevere Thunderstorm WarningEWXMaverick64 min
May 20, 9:00 PM CDTTornado WarningEWXUvalde, Zavala60 min
May 20, 9:03 PM CDTSevere Thunderstorm WarningEWXAtascosa, Frio57 min
May 20, 9:27 PM CDTSevere Thunderstorm WarningEWXTravis63 min
May 20, 9:27 PM CDTTornado WarningEWXVal Verde58 min
May 20, 9:47 PM CDTSevere Thunderstorm WarningEWXKinney58 min
May 20, 10:37 PM CDTSevere Thunderstorm WarningEWXEdwards68 min
May 20, 10:42 PM CDTSevere Thunderstorm WarningEWXMedina, Uvalde, Zavala63 min
May 20, 11:47 PM CDTSevere Thunderstorm WarningEWXMedina, Uvalde, Zavala58 min
May 21, 1:00 AM CDTSevere Thunderstorm WarningEWXUvalde60 min
May 21, 6:17 AM CDTFlash Flood WarningEWXBexar3 hr
May 21, 6:23 PM CDTSevere Thunderstorm WarningEWXLlano67 min

Nearby

Severe Thunderstorm Warnings in Texas, 1987Every severe thunderstorm warning in 1987

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.