Alert archive / Texas / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 128, NWS Austin/San Antonio, TX

May 12, 2000Llano County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 12, 2000, 6:27 PM CDT for Llano County, Texas. It was in force for 63 min. 2 reports came from 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, with what was reported inside it.

The facts

Issued
May 12, 2000, 6:27 PM CDT (23:27 UTC)
Expired
May 12, 2000, 7:30 PM CDT
In force
63 min
Issued by
NWS Austin/San Antonio, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Llano County, TX

What was reported inside it

TimeReportWhereRemark
May 12, 6:40 PM CDTHail 0.88Llano, TX
May 12, 7:07 PM CDTHail 1.75Llano, 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 12, 6:15 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 11.5 hours before the alert went out and 254 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 12:00Z on 2000-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2090 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 12:00Z on 2000-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 236 square meters per square second.1939Sfc1 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
2090 J/kg
Mixed-layer CIN
-527 J/kg
Mixed-layer LCL
1549 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
236 m²/s²
0-3 km storm-relative helicity
253 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KEWX 122328
SVRSAT
TXC299-130030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
627 PM CDT FRI MAY 12 2000

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

* SEVERE THUNDERSTORM WARNING FOR THE FOLLOWING COUNTIES IN TEXAS...
  LLANO COUNTY

* UNTIL 730 PM CDT

* AT 627 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 15 MILES NORTHWEST OF LLANO...MOVING EAST AT 25
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LLANO AROUND 700 PM CDT

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

A TORNADO WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING. PREPARE TO MOVE TO A
PLACE OF SAFETY IN A STURDY STRUCTURE SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM IF A TORNADO IS SPOTTED.


LAT...LON 3090 9895 3054 9894 3053 9844 3092 9847

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 Austin/San Antonio, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at May 12, 2:45 PM CDT, 3 hours 42 minutes earlier.

Area forecast discussion, May 12, 2:45 PM CDT, 3 hours 42 minutes before
SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
245 PM CDT FRI MAY 12 2000

MOST OF THE MODEL RUNS HAVE BEEN FAIRLY CONSISTENT IN BRINGING THE
COLD FRONT WHICH IS IN WEST CENTRAL TEXAS SOUTHWARD ACROSS THE AREA
AND DEVELOPING PRECIPITATION WITH THE FRONT BEGINNING EITHER LATE
THIS AFTERNOON OR THIS EVENING.  WILL KEEP THAT TREND IN CURRENT
FORECAST AND POSSIBLY RAISE POPS IN SOME AREAS.  INCREASING
MIDDLE CLOUDS OVER SOUTHWEST TEXAS INDICATES SOME LIFTING OCCURRING
AS UPPER TROUGH COMES CLOSER.

STEEP LAPSE RATE ABOVE CAP SO ANY THUNDERSTORMS COULD BECOME QUITE
STRONG.  LOW-LEVEL MOISTURE IS FAIRLY LIMITED ESPECIALLY WEST BUT
MAIN TRAJECTORIES BEHIND THE FRONT LATER TONIGHT AND SATURDAY WILL
BE FROM THE EAST WHERE MOISTURE IS BETTER.  COOLER TEMPERATURES ON
TAP FOR AREA BEHIND THE COLD FRONT AIDED BY MOSTLY CLOUDY
CONDITIONS.

COOLER AIR WILL BE DEEPER BUT BEGINNING TO SLIP TO THE EAST ON
SUNDAY AS RAIN THREATS BEGIN TO DECREASE.  A WARMER AND DRIER
PATTERN WILL SET BACK IN MONDAY THROUGH WEDNESDAY AS AN UPPER RIDGE
IS REESTABLISHED OVER THE AREA.

PRELIMINARY NUMBERS
AUS 68/80/60/80 4632
SAT 71/82/63/81 35g32
DRT 72/83/65/82 2321

.EWX...NONE.

16/06/20

In the hours before

Special weather statement, May 12, 2:52 PM CDT, 3 hours 35 minutes before
TXZ171>173-183>194-202>209-217>225-228-122349-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
252 PM CDT FRI MAY 12 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT FOR THE
HILL COUNTRY AND ADJACENT AREAS OF SOUTH CENTRAL TEXAS.  THIS
INCLUDES THE METROPOLITAN AREAS OF AUSTIN AND SAN ANTONIO.
LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREAT.

A DRY LINE IS MOVING SLOWLY EAST INTO THE HILL COUNTRY.  AS IT
ENCOUNTERS THE HOT AND VERY INSTABLE AIR...THUNDERSTORMS WILL
RAPIDLY DEVELOP.  A COLD FRONT MOVING SOUTHEAST TOWARD THE
HILL COUNTRY THIS EVENING AND AN UPPER LEVEL DISTURBANCE WILL
KEEP THE SHOWER AND THUNDERSTORMS PRODUCTION GOING THROUGH THE
NIGHT.  LOCALLY HEAVY RAINFALL IS POSSIBLE WHERE SHOWERS AND
THUNDERSTORMS TRAVERSE THE SAME AREA.

EMERGENCY MANAGEMENT AND STORM SPOTTER GROUPS ARE ADVISED TO MONITOR
THE LATEST WEATHER DEVELOPMENTS THROUGHOUT THE DAY.  SPOTTER
ACTIVATION MAY BE REQUIRED LATER THIS EVENING.

FOR INFORMATION ON WEATHER THREATS IN SURROUNDING AREAS...REFER TO
OUTLOOKS FROM OFFICES IN MIDLAND...SAN ANGELO...FORT WORTH...
HOUSTON/GALVESTON...AND CORPUS CHRISTI.

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 6:39 PM CDTTornado WarningEWXLlano51 min

Nearby

Severe Thunderstorm Warnings in Texas, 2000Every severe thunderstorm warning in 2000

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.