Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 13, NWS Corpus Christi, TX

April 25, 1999La Salle County, Webb County, Texas

NWS Corpus Christi, TX issued this severe thunderstorm warning at Apr 25, 1999, 8:59 AM CDT for La Salle County, Webb County, Texas. It was in force for 61 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Apr 25, 1999, 8:59 AM CDT (13:59 UTC)
Expired
Apr 25, 1999, 10:00 AM CDT
In force
61 min
Issued by
NWS Corpus Christi, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties La Salle County, TX, Webb County, TX

The radar

The Laughlin AFB radar (KDFX), 153 km from the middle of the area, began a volume at 14:00 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 2.0 hours before the alert went out and 191 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 1999-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1211 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 1999-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
1211 J/kg
Mixed-layer CIN
-153 J/kg
Mixed-layer LCL
517 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
187 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

999 
WUUS1 KCRP 251404 RRA
SVRCRP
TXC283-479-251500-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
859 AM CDT SUN APR 25 1999

THE NATIONAL WEATHER SERVICE IN CORPUS CHRISTI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  LA SALLE COUNTY IN TEXAS
  THIS INCLUDES THE CITY OF COTULLA
  EXTREME NORTH CENTRAL WEBB COUNTY IN TEXAS

* UNTIL 1000 AM CDT

* AT 856 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 29 MILES SOUTH OF COTULLA...MOVING NORTHEAST AT
  20 MPH.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN CORPUS CHRISTI.

LAT...LON 2807 9943 2807 9881 2864 9882 2863 9938

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.

NWS Corpus Christi, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 25, 2:55 AM CDT, 6 hours 4 minutes earlier.

Area forecast discussion, Apr 25, 2:55 AM CDT, 6 hours 4 minutes before
COASTAL BEND FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CORPUS CHRISTI TX
255 AM CDT SUN APR 25 1999

THE FNTL ZONE CONTINUES TO RETROGRADE NWWD AS A WARM FNT THROUGH THE
HILL COUNTRY.  THIS WL CONTINUE THROUGH THE DAY AS LOW PRESSURE
DEVELOPS IN W TX.  WE WL CONTINUE TO WEAKEN OUR CAP.  THIS WL BE
MOST EVIDENT OUT WEST WHERE THE CAP IS EXPECTED TO ERODE BY AFTN.
SOME WK DIFL ALOFT...AN APPROACHING THETA-E RDG AXIS AND WK LOW LVL
CONVERGENCE WL BE ENOUGH TO WARRANT SMALL POPS OUT WEST.  DO NOT
REALLY SEE THE NEED FOR POPS FOR THE EAST UNTIL TNT AND MON.  THAT
IS WHEN WE WL SEE MUCH BETTER LIFT...ESPECIALLY THE NRN SECTIONS.
SPLITTING JETS WL ENHANCE THE DIV/DIFL ALOFT.  ALSO THE LOW LVL
MOIST CONVERGENCE WL BE INCREASING WITH TIME AS THE COLD FNT
APPROACHES.  IT LOOKS OUR BEST CHCS AT PCPN WL BE LATE TNT INTO THE
FIRST PART OF MON.  SOME STORMS MAY BE STRONG DUE TO A GOOD DRY
PUNCH OF AIR.

CLOUDS/PCPN CHCS WL BE ENDING RATHER QUICKLY FROM WEST TO EAST ON
MON ACROSS MOST OF THE AREA.  THE ERN SECTIONS WL LKLY TAKE UNTIL
MON NIGHT TO CLEAR OUT AS THE FNT WL BEGIN STALLING AND WEAKENING AS
IT REACHES THE COAST.  THE WINDS WL BE WEAKENING ON MON GIVEN THE
APPROACHING WK FNT.

PRELIMS FOLLOW...
CRP EE 083/074 081/063 086 123
VCT EE 083/072 080/061 084 134
LRD EB 088/075 091/062 091 222
NGP EE 082/074 080/068 084 123

MB(SYN)...80
JM(MESO)...75

.CRP...NONE.

Nearby

Severe Thunderstorm Warnings in Texas, 1999Every severe thunderstorm warning in 1999

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; radar from the NEXRAD Level II archive.