Alert archive / Texas / Severe Thunderstorm Warnings in 2011

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

May 20, 2011Bastrop County, Caldwell County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 20, 2011, 10:02 PM CDT for Bastrop County, Caldwell County, Texas. It was in force for 43 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 20, 2011, 10:02 PM CDT (03:02 UTC)
Expired
May 20, 2011, 10:45 PM CDT
In force
43 min
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon

Counties Bastrop County, TX, Caldwell County, TX

The radar

The Austin/San Antonio radar (KEWX), 61 km from the middle of the area, began a volume at 03:05 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.

What was reported inside it

TimeReportWhereRemark
May 20, 10:17 PM CDTHAIL 0.756 Wsw Cedar Creek, TXHAIL AT LEGEND OAKS DRIVE AND HIGHWAY 21 IN CEDAR CREEK.
May 20, 10:17 PM CDTHAIL 1.256 Wsw Cedar Creek, TXHAIL AT LEGEND OAKS DRIVE AND HIGHWAY 21 IN CEDAR CREEK.
May 20, 10:26 PM CDTHAIL 0.755 Wsw Cedar Creek, TXHAILING PEA TO PENNY SIZED HAIL FOR THE LAST 10 MINUTES.
May 20, 10:32 PM CDTHAIL 15 Se Cedar Creek, TXPEA TO QUARTER SIZE HAIL.
May 20, 10:39 PM CDTHAIL 0.55 Sse Cedar Creek, TXPEA TO HALF INCH HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 3.0 hours before the alert went out and 252 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 00:00Z on 2011-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4855 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 00:00Z on 2011-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
4855 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
870 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
1.3
Supercell composite
9.0

Open this sounding in Storm Lab

The text

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

546 
WUUS54 KEWX 210302
SVREWX
TXC021-055-210345-
/O.NEW.KEWX.SV.W.0076.110521T0302Z-110521T0345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1002 PM CDT FRI MAY 20 2011

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL BASTROP COUNTY...
  NORTHERN CALDWELL COUNTY...

* UNTIL 1045 PM CDT.

* AT 954 PM CDT...NWS METEOROLOGISTS HAVE DETECTED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND DAMAGING
  WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR MENDOZA...
  OR 8 MILES NORTH OF LOCKHART...AND MOVING EAST AT 15 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE LYTTON SPRINGS...ST JOHN
  COLONY...DALE...MCMAHAN...BATEMAN...TAYLORSVILLE...ELM GROVE...
  ROCKNE...RED ROCK...HILLS PRAIRIE AND WATTERSON.

LAT...LON 3006 9727 2983 9750 2994 9777 3007 9765
TIME...MOT...LOC 0302Z 287DEG 15KT 2998 9762

$$
1 follow-up statement
117 
WWUS54 KEWX 210327
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1027 PM CDT FRI MAY 20 2011

TXC021-055-210345-
/O.CON.KEWX.SV.W.0076.000000T0000Z-110521T0345Z/
BASTROP TX-CALDWELL TX-
1027 PM CDT FRI MAY 20 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT
FOR NORTHERN CALDWELL AND WEST CENTRAL BASTROP COUNTIES...

AT 1018 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG
A LINE EXTENDING FROM 9 MILES NORTH OF HILLS PRAIRIE TO 10 MILES
SOUTHWEST OF MENDOZA...OR ALONG A LINE EXTENDING FROM BASTROP TO 6
MILES WEST OF LOCKHART...MOVING EAST AT 10 MPH.

SOME LOCATIONS IN THE WARNING AREA INCLUDE LYTTON SPRINGS...ST JOHN
COLONY...DALE...MCMAHAN...TAYLORSVILLE...WATTERSON...ROCKNE...RED
ROCK...BATEMAN AND ELM GROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HAIL UP TO HALF DOLLAR SIZE HAS BEEN REPORTED 6 MILES WEST SOUTHWEST 
OF CEDAR CREEK WITH THIS STORM. IF YOU ARE IN THE PATH OF THE 
STORM...TAKE IMMEDIATE ACTION TO PROTECT LIFE AND PROPERTY.

&&

LAT...LON 3007 9761 3006 9727 2983 9750 2994 9777
TIME...MOT...LOC 0326Z 282DEG 9KT 3017 9733 2988 9776

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 7:49 PM CDTSevere Thunderstorm WarningEWXBastrop, Hays, Travis, Williamson41 min
May 20, 8:04 PM CDTSevere Thunderstorm WarningEWXBastrop, Caldwell, Hays, Travis26 min
May 20, 8:27 PM CDTSevere Thunderstorm WarningEWXCaldwell, Hays, Travis23 min
May 20, 8:58 PM CDTSevere Thunderstorm WarningEWXHays, Travis32 min
May 20, 8:59 PM CDTSevere Thunderstorm WarningEWXBastrop, Lee, Travis, Williamson61 min
May 20, 9:22 PM CDTSevere Thunderstorm WarningEWXBastrop, Caldwell, Lee, Travis38 min
May 20, 10:32 PM CDTSevere Thunderstorm WarningEWXCaldwell, Guadalupe, Hays43 min
May 21, 4:58 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano, Williamson47 min
May 21, 5:44 PM CDTSevere Thunderstorm WarningEWXBurnet, Williamson46 min
May 21, 6:00 PM CDTAreal Flood AdvisoryEWXBurnet, Llano2 hr
May 21, 6:00 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano45 min
May 21, 6:29 PM CDTSevere Thunderstorm WarningEWXBurnet, Williamson46 min
May 21, 6:52 PM CDTSevere Thunderstorm WarningEWXBurnet, Williamson38 min
May 21, 6:59 PM CDTTornado WarningEWXBurnet31 min

Nearby

Severe Thunderstorm Warnings in Texas, 2011Every severe thunderstorm warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.