Alert archive / Texas / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 76, NWS Austin/San Antonio, TX

May 20, 2001Karnes County, Wilson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 2001, 7:28 PM CDT for Karnes County, Wilson County, Texas. It was in force for 62 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: May 20, 2001, 7:28 PM CDT (00:28 UTC)
Expired: May 20, 2001, 8:30 PM CDT
In force: 62 min
Issued by: NWS Austin/San Antonio, TX
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Karnes County, TX, Wilson County, TX

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 0.5 hours before the alert went out and 166 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1709 J/kg
Mixed-layer CIN: -209 J/kg
Mixed-layer LCL: 1168 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

210 
WUUS54 KEWX 210029
SVRSAT
TXC255-493-210130-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
728 PM CDT SUN MAY 20 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR THE FOLLOWING COUNTIES IN TEXAS...
  WILSON
  KARNES

* UNTIL 830 PM CDT

* AT 728 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 7 MILES SOUTHWEST OF FALLS CITY...OR ABOUT 11
  MILES SOUTH OF POTH...MOVING NORTHEAST AT 20 MPH.

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.


LAT...LON 2913 9833 2875 9800 2883 9769 2908 9781
          2922 9780 2933 9789 2939 9815

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 20, 2:15 PM CDT, 5 hours 13 minutes earlier.

Area forecast discussion, May 20, 2:15 PM CDT, 5 hours 13 minutes before

SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
215 PM CDT SUN MAY 20 2001

AFTER A BRIEF STINT WITH SHOWERS AND THUNDERSTORMS TOMORROW...A COLD
FRONT WILL USHER IN COOLER AND MUCH DRIER AIR...WITH THE GULF OF
MEXICO FLOW BEING SHUT OFF FOR MOST OF THE WEEK.  THE EXTENDED HAS A
GOOD RETURN FLOW OF MOISTURE BY NEXT SUNDAY.

WE ARE POTENTIALLY VERY UNSTABLE ALOFT WITH THE LATEST GOES CAPE
INDEX SHOWING CAPES OF 3000-5000.  HOWEVER...WE ARE JUST NOW
CLEARING ACROSS THE EASTERN PORTIONS OF SOUTH CENTRAL TEXAS AND
VISUAL CLUES OF GOOD SUBSIDENCE OCCURRING (VISIBILITIES LOWERING IN
HAZE). WITH LITTLE IN WAY OF FOCUS OR POSITIVE DYNAMICS ALOFT...
WILL ONLY PLACE ISOLATED SHOWERS OR THUNDERSTORMS WEST TONIGHT...
WHERE DRY LINE SET UP WILL BE.

MODELS HAVE BEEN VERY CONSISTENT IN BRINGING IN A GOOD COLD FRONT
AROUND MIDDAY MONDAY...AND THIS CONTINUES THE CASE.  A BRIEF SHOT AT
SOME SHOWERS AND THUNDERSTORMS ALONG THE FRONT WITH GOOD LOW LEVEL
FORCING. THE TIME OF DAY PRECLUDES US FROM GOING ANY HIGHER THAN 30
PERCENT AT PRESENT.  SOME CYCLOGENESIS ALONG THE COASTLINE MONDAY
NIGHT WILL FORCE US TO CONTINUE WITH LOW POPS (MOSTLY LIGHT RAIN OR
SHOWERS) OVER THE SOUTH CENTRAL AND SOUTHEAST ZONES TOMORROW NIGHT.

MASSIVE VORTEX DEVELOPING ACROSS UPPER MIDWEST INTO THE NORTHEAST
U.S. BY MIDWEEK KEEPS AREA DRY AND A LITTLE COOLER THAN NORMAL.
SECONDARY WAVE PUSHES IN LATE THURSDAY WITH A FEW MORE CLOUDS AND A
REINFORCEMENT OF COOL AIR.   SOUTHERLY FLOW FINALLY RETURNS WITH A
VENGEANCE SUNDAY AS THE HIGH MOVES OFF INTO THE ATLANTIC WHILE A
LONGWAVE TROUGH PATTERN SETS UP OVER THE WESTERN U.S.

PRELIMINARY NUMBERS...
AUS 072/080/051/081 0310
DRT 068/089/057/085 1200
SAT 074/083/053/081 0320

.EWX...NONE.

02/19

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 7:09 PM CDT	Severe Thunderstorm Warning	EWX	Llano	66 min
May 20, 7:10 PM CDT	Severe Thunderstorm Warning	EWX	Caldwell	65 min
May 20, 7:51 PM CDT	Severe Thunderstorm Warning	EWX	Burnet	69 min
May 20, 8:29 PM CDT	Tornado Warning	EWX	Burnet	31 min
May 20, 8:45 PM CDT	Tornado Warning	EWX	Travis, Williamson	60 min
May 20, 9:47 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Lee, Travis, Williamson	43 min
May 21, 6:39 AM CDT	Flash Flood Warning	EWX	Guadalupe	2 hr

Nearby

Severe Thunderstorm Warnings in Texas, 2001 Every severe thunderstorm warning in 2001

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.