Alert archive / Texas / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 36, NWS Austin/San Antonio, TX

May 20, 1990Webb County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 1990, 5:45 PM CDT for Webb County, Texas. It was in force for 90 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, 1990, 5:45 PM CDT (22:45 UTC)
Expired
May 20, 1990, 7:15 PM CDT
In force
90 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Webb 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, 6:45 PM CDTHail 1.25Webb, 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

Corpus Christi, TX (KCRP), launched 12:00Z, 10.8 hours before the alert went out and 196 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, Corpus Christi, TX at 12:00Z on 1990-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1896 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, Corpus Christi, TX at 12:00Z on 1990-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 square meters per square second.19395878Sfc1 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
1896 J/kg
Mixed-layer CIN
-395 J/kg
Mixed-layer LCL
1062 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
76 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSAT 202244
SVRSAT
TXC479-210015-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN ANTONIO TX
545 PM CDT SUN MAY 20 1990
 
THE NATIONAL WEATHER SERVICE IN SAN ANTONIO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 715 PM CDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH TEXAS
          ...WEBB
 
A SEVERE THUNDERSTORM WAS INDICATED BY RADAR 10 MILES NORTH OF THE
CITY OF LAREDO. THE STORM WAS MOVING TO THE NORTHEAST AT 20 MPH.
BECAUSE OF THE EXTREME HEAT THAT OCCURRED IN THE LAREDO AREA THIS
AFTERNOON...DAMAGING WINDS ARE VERY POSSIBLE IN THIS STORM.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...HAIL
3/4 INCH OR MORE IN6 DIAMETER...FREQUENT LIGHTNING AND VERY HEAVY
RAIN.
 
YOU SHOULD ASK THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY YOUR
SEVERE WEATHER REPORTS TO THE LOCAL NATIONAL WEATHER SERVICE OFFICE.

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, 11:47 AM CDT, 5 hours 58 minutes before
TXZ030-036-201800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN TX
1145 AM CDT SUN MAY 20 1990

...THUNDERSTORMS DIMINISHING OVER THE HILL COUNTRY...

AT 1130 AM...RADAR INDICATED A LARGE AREA OF SHOWERS WITH A FEW
EMBEDDED THUNDERSTORMS FROM NORTH OF WACO TO SOUTH AND WEST OF AUSTIN
SOUTHWEST TO SOUTH OF SAN ANTONIO. THE STRONGER STORMS WERE ABOUT 30
MILES EAST OF LAKE BUCHANAN. THE STORMS WERE MOVING NORTHEAST AT NEAR
20 MPH.

THIESE THUNDERSTORMS HAVE BEEN DECREASING IN INTENSITY AND AREA COVERAGE
OVER THE PAST HOUR BUT MAY PRODUCE SOME BRIEF LOCALLY HEAVY RAIN.
Special weather statement, May 20, 4:45 PM CDT, 1 hour before
TXZ035-040-202240-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANTONIO, TX
445 PM CDT SUN MAY 20 1990

AT 440 PM THIS AFTERNOON...NATIONAL WEATHER SERVICE RADAR INDICATED A
THUNDERSTORM WITH VERY HEAVY RAIN IN MEXICO...APPROXIMATELY 15 MILES
SOUTHWEST OF THE CITY OF LAREDO.  THE THUNDERSTORM WAS MOVING TO THE
NORTHEAST AT 10 MPH.

BECAUSE THE ATMOSPHERE IS VERY UNSTABLE THIS AFTERNOON...AND BECAUSE
OF AFTERNOON TEMPERATURES WELL OVER 100 DEGREES IN THE LAREDO AREA...
THIS STORM ALSO HAS THE POTENTIAL OF PRODUCING VERY STRONG AND POSSIBLY
DAMAGING WINDS.  IF THE STORM CONTINUES TO MOVE AT ITS CURRENTLY
DIRECTION AND SPEED IT WILL REACH THE CITY OF LAREDO NEAR 600 PM THIS
EVENING.
Special weather statement, May 20, 5:36 PM CDT, 9 minutes before
TXZ035-040-202340-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANTONIO, TX
537 PM CDT SUN MAY 20 1990

SCATTERED THUNDERSTORMS...SOME WITH VERY HEAVY RAINFALL...CONTINUED
AT 530 PM BETWEEN LAREDO AND COTULLA.  THE THUNDERSTORMS WERE MOVING
TO THE NORTHEAST AT 20 MPH.

TEMPERATURES REACHED 109 DEGREES IN LAREDO THIS AFTERNOON...WITH 102
DEGREES REPORTED AT COTULLA.  SUCH EXTREME HEAT DEVELOPES THUNDERSTORMS
WITH BASES SEVERAL THOUSAND FEET ABOVE THE GROUND.  A STORM OF THIS TYPE
HAS THE POTENTIAL FOR PRODUCING VERY STRONG AND GUSTY WINDS...THAT AT
TIMES CAN BE DAMAGING.  OFTEN THE RAIN FALLING FROM THESE STORMS IS SEEN
TO EVAPORATE BEFORE IT REACHES THE GROUND.  IS IS A VISUAL SIG.N THAT THE
STORMS COULD PRODUCE DAMAGING WINDS.

Nearby

Severe Thunderstorm Warnings in Texas, 1990Every severe thunderstorm warning in 1990

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.