Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 40, NWS Austin/San Antonio, TX

March 18, 1999Val Verde County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Mar 18, 1999, 12:49 AM CST for Val Verde County, Texas. It was in force for 76 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Mar 18, 1999, 12:49 AM CST (06:49 UTC)
Expired
Mar 18, 1999, 2:05 AM CST
In force
76 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties

County Val Verde County, TX

The radar

The Laughlin AFB radar (KDFX), 109 km from the middle of the area, began a volume at 06:53 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

Del Rio, TX (KDRT), launched 00:00Z, 6.8 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-pSkew-T log-p diagram, Del Rio, TX at 00:00Z on 1999-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 834 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 1999-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.1939587897Sfc1 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
834 J/kg
Mixed-layer CIN
-195 J/kg
Mixed-layer LCL
1444 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
280 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.6

Open this sounding in Storm Lab

The text

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

999 
WUUS1 KSAT 180648 RRA
SVRSAT
TXC465-180805-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1249 AM CST THU MAR 18 1999

THE NATIONAL WEATHER SERVICE IN AUSTIN/SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  VAL VERDE COUNTY IN TEXAS

* UNTIL 205 AM CST

* AT 1245 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 5 MILES NORTHEAST OF COMSTOCK MOVING TOWARDS
  THE NORTHEAST AT NEAR 20.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CARTA VALLEY AND LOMA ALTA BY 1 AM.

SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING. GO INSIDE A STURDY BUILDING AND
STAY AWAY FROM WINDOWS

JDS

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 17, 9:39 PM CSTSevere Thunderstorm WarningEWXVal Verde61 min
Mar 17, 10:46 PM CSTSevere Thunderstorm WarningEWXVal Verde59 min
Mar 17, 11:08 PM CSTTornado WarningEWXVal Verde32 min
Mar 18, 2:18 AM CSTSevere Thunderstorm WarningEWXEdwards72 min
Mar 18, 3:25 AM CSTSevere Thunderstorm WarningEWXEdwards60 min
Mar 18, 5:24 AM CSTFlash Flood WarningEWXReal3 hr
Mar 18, 8:47 AM CSTFlash Flood WarningEWXGillespie3 hr
Mar 18, 9:31 AM CSTFlash Flood WarningEWXKerr3 hr
Mar 18, 9:46 AM CSTFlash Flood WarningEWXLlano3 hr
Mar 18, 12:10 PM CSTFlash Flood WarningEWXGillespie110 min
Mar 18, 12:41 PM CSTFlash Flood WarningEWXLlano114 min
Mar 18, 2:49 PM CSTFlash Flood WarningEWXLlano2 hr

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.