Alert archive / Texas / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 96, NWS Austin/San Antonio, TX

May 20, 1987Comal County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 1987, 7:42 PM CDT for Comal County, Texas. It was in force for 63 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
May 20, 1987, 7:42 PM CDT (00:42 UTC)
Expired
May 20, 1987, 8:45 PM CDT
In force
63 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Comal County, TX

The radar

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

What was reported inside it

TimeReportWhereRemark
May 20, 8:30 PM CDTHail 1.75Comal, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Victoria Regiona, TX (KVCT), launched 00:00Z, 0.7 hours before the alert went out and 171 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, Victoria Regiona, TX at 00:00Z on 1987-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2069 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, Victoria Regiona, TX at 00:00Z on 1987-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
2069 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
921 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSAT 210042
SVRSAT
TXC091-210145-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN ANTONIO TX
742 PM CDT WED MAY 20 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 845 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH TEXAS
          ...COMAL
 
AT 745 PM CDT...A SEVERE THUNDERSTORM WAS INDICATED BY RADAR BETWEEN
SAN ANTONIO AND NEW BRAUNFELS ON THE BEXAR-COMAL COUNTY LINE...ALONG
IH 35.  THIS THUNDERSTORM IS MOVING TOWARD THE NORTH AT 15 MPH.
MARBLE-SIZED HAIL AND BRIEF HEAVY RAIN HAS BEEN REPORTED WITH THIS
STORM AS IT MOVED ACROSS NORTHEAST SAN ANTONIO DURING THE PAST HOUR.
 
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.
 
YOU SHOULD ASK THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY YOUR
SEVERE WEATHER REPORTS TO THE LOCAL NATIONAL WEATHER SERVICE OFFICE.
 
PLEASE LISTEN TO YOUR LOCAL RADIO...TV OR NOAA WEATHER RADIO STATION
FOR LATER STATEMENTS OR WARNINGS REGARDING THIS SEVERE WEATHER EVENT.

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, 2 hours 28 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, 1 hour 36 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.
Local storm report, May 20, 7:04 PM CDT, 38 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE SAN ANTONIO TX
700 PM CDT WED MAY 20 1987

TIME         EVENT

 540 PM      PEA SIZE HAIL AT DERBY...FRIO COUNTY
 618 PM      MARBLE SIZE HAIL IN DILLEY...FRIO COUNTY
 619 PM      MARBLE SIZE HAIL AT FAIRVIEW...WILSON COUNTY
 625 PM      PEA SIZE HAIL IN CHARLOTTE...ATASCOSA COUNTY
 626 PM      PEA SIZE HAIL AT LAKE CALAVARAS...BEXAR COUNTY
 630 PM      HAIL SIZE UNKNOWN...WESTERN WILSON COUNTY
 635 PM      S4 INCH DIAMETER HAIL AT DILLEY...FRIO COUNTY
 647 PM      PEA TO GOLF BALL SIZE HAIL SOUTHEAST OF LAKE CALAVARAS
             ...BEXAR COUNTY
Special weather statement, May 20, 7:18 PM CDT, 24 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DEL RIO TX
718 PM CDT WED MAY 20 1987

AT 715 PM CDT AN AREA OF THUNDERSTORMS WAS DEVELOPING ABOUT 35 MILES
WEST OF DEL RIO...BETWEEN COMSTOCK AND LANGTRY...AND WAS MOVING
NORTHEAST INTO VAL VERDE COUNTY AT 15 MPH.  AN ENTENSE THUNDERSTORM
WITHIN THIS AREA WAS SOUTHEAST OF COMSTOCK AN JUST SOUTH OF THE RIO
GRANDE RIVER.  PERSONS LIVING BETWEEN BETWEEN COMSTOCK AND LANGTRY
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. DANGEROUS CLOUD TO GROUND LIGHTNINhG HAS BEEN REPORTED
OUT OF THESE THUNDERSTORMS.

HEAVY RAIN...GUSTY WINDS...SMALL HAIL AND DANGEROUS LIGHTNING ARE
QUITE LIKELY FROM THESE THUNDERSTORMS.
Special weather statement, May 20, 7:40 PM CDT, 2 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.

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, 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, 10:20 PM CDTSevere Thunderstorm WarningEWXVal Verde60 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.