Alert archive / Texas / Tornado Warnings in 1987

Tornado Warning 10, NWS Austin/San Antonio, TX

May 20, 1987Val Verde County, Texas

NWS Austin/San Antonio, TX issued this tornado warning at May 20, 1987, 9:27 PM CDT for Val Verde County, Texas. It was in force for 58 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, 9:27 PM CDT (02:27 UTC)
Expired: May 20, 1987, 10:25 PM CDT
In force: 58 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.

What was reported inside it

Time	Report	Where	Remark
May 20, 10:01 PM CDT	Thunderstorm Wind 60	Val Verde, 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

Del Rio, TX (KDRT), launched 00:00Z, 2.5 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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 210228
TORDRT
TXC465-210325-

BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DEL RIO TX
927 PM CDT WED MAY 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING EFFECTIVE
UNTIL 1025 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY IN

SOUTHCENTRAL TEXAS...VAL VERDE.

AT 920 PM THE LAUGHLIN AFB RADAR INDICATED A POSSIBLE TORNADO WAS
LOCATED 10 WEST OF DEL RIO AND WAS MOVING EAST AT 15 MILES AN HOUR.

THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE IN
THE PATH OF THIS TORNADO MOVE TO A SMALL INTERIOR ROOM ON THE
LOWEST FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND
MOBILE HOMES FOR A REINFORCED BUILDING OR GET INTO A DITCH
OR CULVERT BUT REMAIN ALERT FOR FLASH FLOODING.

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Local storm report, May 20, 7:04 PM CDT, 2 hours 23 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, 2 hours 9 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, 1 hour 47 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, 1 hour 18 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 4 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, 59 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

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 7:11 PM CDT	Severe Thunderstorm Warning	EWX	Wilson	64 min
May 20, 7:38 PM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Frio	67 min
May 20, 7:42 PM CDT	Severe Thunderstorm Warning	EWX	Comal	63 min
May 20, 8:34 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Hays	56 min
May 20, 8:50 PM CDT	Severe Thunderstorm Warning	EWX	Val Verde	56 min
May 20, 8:56 PM CDT	Severe Thunderstorm Warning	EWX	Maverick	64 min
May 20, 9:00 PM CDT	Tornado Warning	EWX	Uvalde, Zavala	60 min
May 20, 9:03 PM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Frio	57 min
May 20, 9:27 PM CDT	Severe Thunderstorm Warning	EWX	Travis	63 min
May 20, 9:47 PM CDT	Severe Thunderstorm Warning	EWX	Kinney	58 min
May 20, 10:20 PM CDT	Severe Thunderstorm Warning	EWX	Val Verde	60 min
May 20, 10:37 PM CDT	Severe Thunderstorm Warning	EWX	Edwards	68 min
May 20, 10:42 PM CDT	Severe Thunderstorm Warning	EWX	Medina, Uvalde, Zavala	63 min
May 20, 11:47 PM CDT	Severe Thunderstorm Warning	EWX	Medina, Uvalde, Zavala	58 min
May 21, 1:00 AM CDT	Severe Thunderstorm Warning	EWX	Uvalde	60 min
May 21, 6:17 AM CDT	Flash Flood Warning	EWX	Bexar	3 hr
May 21, 6:23 PM CDT	Severe Thunderstorm Warning	EWX	Llano	67 min

Nearby

Tornado Warnings in Texas, 1987 Every tornado warning in 1987 Tornadoes 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.