Alert archive / Texas / Flash Flood Warnings in 1987

Flash Flood Warning 77, NWS Austin/San Antonio, TX

June 12, 1987Dimmit County, La Salle County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jun 12, 1987, 1:31 AM CDT for Dimmit County, La Salle County, Texas. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jun 12, 1987, 1:31 AM CDT (06:31 UTC)
Expired
Jun 12, 1987, 5:30 AM CDT
In force
4 hr
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

Counties Dimmit County, TX, La Salle 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, 6.5 hours before the alert went out and 176 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 1987-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1550 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 1987-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
1550 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1020 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-0.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSAT 120631
FFWSAT
TXC127-283-121030-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN ANTONIO TX
131 AM CDT FRI JUN 12 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL  530 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTH TEXAS
          ...DIMMIT...LASALLE
 
RADAR INDICATES THAT THUNDERSTORMS PRODUCING HEAVY RAINFALL HAVE
MOVED INTO THE NORTHERN PORTIONS OF DIMMIT AND LASALLE COUNTIES.
THESE THUNDERSTORMS ARE MOVING VERY SLOWLY AND RAINFALL RATES OF UP
TO 3 INCHES PER HOUR ARE POSSIBLE. FLOODING OF LOW WATER CROSSINGS
AND LOW LYING AREAS IS POSSIBLE AND MOTORISTS SHOULD EXERCISE
CAUTION.
 
DANGEROUS LIGHTNING AND GUSTY WINDS OFTEN ACCOMPANY FLASH FLOOD
PRODUCING THUNDERSTORMS.
 
PLEASE LISTEN TO YOUR LOCAL RADIO...TV OR NOAA WEATHER RADIO STATION
FOR LATER STATEMENTS OR WARNINGS REGARDING THIS SEVERE WEATHER EVENT.
 
DANGEROUS LIGHTNING AND GUSTY WINDS OFTEN xACCOMPANY FLASH FLOOD

What forecasters said that day

The local office's own words before this flash flood 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, Jun 11, 8:06 PM CDT, 5 hours 25 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DEL RIO TX
810 PM CDT THU JUN 11 1987

AT 805 PM CDT RADAR INDICATED THUNDERSTORMS 50 MILES NORTHWEST OF DEL
RIO. PANDALE CROSSING...60 MILES NORTHWEST OF DEL RIO...REPORTED
THUNDERSTORMS WITH HEAVY RAIN...STRONG GUSTY WINDS AND FREQUENT
DANGEROUS LIGHTNING DURING THE PAST FIVE MINUTES. THESE STORMS WERE
MOVING TO THE EAST NORTHEAST AT 10 MPH...BUT ALSO BUILDING TO THE
SOUTHEAST TOWARD DEL RIO.

SOME LOW AREAS OF ROADWAYS MAY BECOME FLOODED...HIGHWAYS 163 AND 189
IN NORTHERN VAL VERDE COUNTY ARE ALREADY CLOSED. MOTORISTS ARE URGED
TO USE CAUTION AND NOT TO ATTEMPT TO CROSS FLOODED LOW WATER
CROSSINGS. CAMPERS AND CANOEISTS ALONG THE PECOS RIVER SHOULD USE
EXTREME CAUTION...KEEP A LOOKOUT AND BE READY TO MOVE TO HIGHER
GROUND.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 11, 8:11 PM CDTFlash Flood WarningEWXBandera, Kerr4 hr
Jun 11, 8:18 PM CDTFlash Flood WarningEWXGillespie3 hr
Jun 11, 9:43 PM CDTFlash Flood WarningEWXUvalde3 hr
Jun 11, 11:06 PM CDTFlash Flood WarningEWXMedina4 hr
Jun 12, 12:05 AM CDTFlash Flood WarningEWXFrio4 hr

Nearby

Flash Flood Warnings in Texas, 1987Every flash flood 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.