Alert archive / Texas / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 93, NWS Austin/San Antonio, TX

May 20, 1987Frio County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 1987, 6:39 PM CDT for Frio County, Texas. It was in force for 66 min.

The area

The counties it named.

The facts

Issued
May 20, 1987, 6:39 PM CDT (23:39 UTC)
Expired
May 20, 1987, 7:45 PM CDT
In force
66 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Frio 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 12:00Z, 11.7 hours before the alert went out and 177 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 1987-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 52 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 1987-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 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
52 J/kg
Mixed-layer CIN
-344 J/kg
Mixed-layer LCL
1692 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
100 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSAT 202339 RRA
SVRSAT
TXC163-210045-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN ANTONIO TX
639 PM CDT WED MAY 20 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  745 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH TEXAS
          ...FRIO
 
A SEVERE THUNDERSTORM IN SOUHTERN FRIO COUNTY HAS PRODUCED HAIL UP TO
FOUR INCHS IN DIAMETER. THIS STORM HAS BEEN DRIFTING TO THE NORTH BUT
CAN CHANCE DIRECTIONS SUDDENLY. ANOTHER SEVERE STORM IN THE
NORTHWESTERN PART OF THE COUNTY HAS BEEN MOVING TO THE NORTHWEST AT
ABOUT 10 MPH.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...HAIL
3/4 INCH OR MORE IN DIAMETER...FREQUENT LIGHTNING AND VERY HEAVY
RAIN.
 
WHEN A THUNDERSTORM THREATENS...SEEK SHELTER INSIDE A HOME OR
BUILDING AWAY FROM DOORS AND WINDOWS.  REFRAIN FROM USING ELECTRICAL
APPLIANCES. SEVERE THUNDERSTORMS CAN AND OCCASIONALL1Y DO PRODUCE
TORNADOES WITH LITTLE OR NO WARNING.

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, 5:14 PM CDT, 1 hour 25 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANTONIO TX
515 PM CDT WED MAY 20 1987

HONDO RADAR INDICATES A THUNDERSTORM HAS DEVELOPED IN THE DILLEY AREA...
IN SOUTHERN FRIO COUNTY...DURING THE PAST HALF HOUR.

THIS THUNDERSTORM LIKELY CONTAINS SMALL HAIL...FREQUENT LIGHTNING...
GUSTY WINDS AND LOCALLY HEAVY RAIN WHICH MAY CAUSE LOCALIZED FLOODING
OF LOW-LYING AREAS IN AND AROUND DILLEY AND SOUTHERN FRIO COUNTY.  THE
FRIO RIVER MAY COLLECT SOME OF THIS RUNOFF AND REFLECT SMALL RISES
DOWNSTREAM BELOW DILLEY TONIGHT.

THE MOVEMENT OF THIS THUNDERSTORM IS TOWARD THE NORTHEAST...WHICH WILL
TRACK IT ALONG INTERSTATE 35.  TRAVEL BETWEEN DEVINE...PEARSALL AND
DILLEY MAY BE RESTRICTED BY HEAVY RAIN...SLICK ROADWAYS AND REDUCED
VISIBILITY FOR ANOTHER HOUR OR SO.

ADDITIONAL STATEMENTS OR WARNINGS WILL BE ISSUED AS CONDITIONS
WARRANT...SO PLEASE STAY TUNED.
Special weather statement, May 20, 6:06 PM CDT, 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANTONIO TX
610 PM CDT WED MAY 20 1987

HONDO RADAR INDICATES A THUNDERSTORM HAS DEVELOPED BETWEEN SAN ANTONIO
AND FLORESVILLE...IN EXTREME WESTERN WILSON COUNTY.

THIS THUNDERSTORM LIKELY CONTAINS SMALL HAIL...FREQUENT LIGHTNING...
GUSTY WINDS AND LOCALLY HEAVY RAIN WHICH MAY CAUSE LOCALIZED FLOODING
OF LOW-LYING AREAS BETWEEN SAN ANTONIO AND FLORESVILLE.  FISHERMEN AND
BOATERS CLOSE TO BRAUNIG LAKE AND CALAVERAS LAKE SHOULD SEEK SHELTER
AND MOVE TO SHORE AND AWAY FROM THE WATER AT ONCE.

THE MOVEMENT OF THIS THUNDERSTORM WILL TAKE IT ACROSS EXTREME EASTERN
BEXAR COUNTY...TO THE EAST OF THE CITY OF SAN ANTONIO.  MOTORISTS ON
US 181 SHOULD BE ALERT FOR REDUCED VISIBILITIES IN HEAVY RAIN...AS
WELL AS SLICK AND WET ROADS AND HIGHWAYS.

ADDITIONAL STATEMENTS OR WARNINGS WILL BE ISSUED AS CONDITIONS
WARRANT...SO PLEASE STAY TUNED.

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 7:26 PM CDTFlash Flood WarningEWXBexar3 hr
May 19, 8:00 PM CDTSevere Thunderstorm WarningEWXBexar60 min
May 19, 8:09 PM CDTFlash Flood WarningEWXGuadalupe3 hr
May 19, 8:28 PM CDTTornado WarningEWXBexar62 min
May 19, 8:50 PM CDTSevere Thunderstorm WarningEWXMcMullen55 min
May 19, 9:16 PM CDTSevere Thunderstorm WarningEWXGuadalupe59 min
May 19, 9:39 PM CDTSevere Thunderstorm WarningEWXWilson66 min
May 19, 10:55 PM CDTSevere Thunderstorm WarningEWXGonzales, Karnes65 min
May 19, 11:20 PM CDTSevere Thunderstorm WarningEWXDeWitt55 min
May 20, 12:05 AM CDTSevere Thunderstorm WarningEWXLavaca55 min
May 20, 5:44 PM CDTSevere Thunderstorm WarningEWXFrio61 min
May 20, 6:13 PM CDTSevere Thunderstorm WarningEWXBexar2 hr

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.