Alert archive / Texas / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 80, NWS Austin/San Antonio, TX

May 21, 2011Burnet County, Llano County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 21, 2011, 6:00 PM CDT for Burnet County, Llano County, Texas. It was in force for 45 min. 2 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 21, 2011, 6:00 PM CDT (23:00 UTC)
Expired: May 21, 2011, 6:45 PM CDT
In force: 45 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

Counties Burnet County, TX, Llano County, TX

The radar

The Ft Hood radar (KGRK), 100 km from the middle of the area, began a volume at 23:00 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.

What was reported inside it

Time	Report	Where	Remark
May 21, 6:12 PM CDT	HAIL 0.88	Tow, TX
May 21, 6:12 PM CDT	HAIL 1	2 E Tow, TX

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

The watch it was issued in

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

Issued	Product	Office	Lasted
May 21, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 11.0 hours before the alert went out and 233 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: 87 J/kg
Mixed-layer CIN: -337 J/kg
Mixed-layer LCL: 1835 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 203 m²/s²
0-3 km storm-relative helicity: 181 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

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

458 
WUUS54 KEWX 212300
SVREWX
TXC053-299-212345-
/O.NEW.KEWX.SV.W.0080.110521T2300Z-110521T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
600 PM CDT SAT MAY 21 2011

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN BURNET COUNTY...
  NORTHEASTERN LLANO COUNTY...

* UNTIL 645 PM CDT.

* AT 555 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    
  TOW...OR 9 MILES NORTH OF BUCHANAN DAM...AND MOVING EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL OTHERWISE IMPACT MAINLY RURAL AREAS OF
  THE INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

&&

LAT...LON 3104 9823 3083 9823 3083 9850 3093 9851
      3094 9845 3095 9846 3099 9845 3102 9847
TIME...MOT...LOC 2300Z 268DEG 25KT 3092 9840

$$

1 follow-up statement

933 
WWUS54 KEWX 212336
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
636 PM CDT SAT MAY 21 2011

TXC053-299-212345-
/O.CON.KEWX.SV.W.0080.000000T0000Z-110521T2345Z/
BURNET TX-LLANO TX-
636 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR NORTHEASTERN LLANO AND NORTHWESTERN BURNET COUNTIES...

AT 629 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND DAMAGING
WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 7 MILES EAST OF
TOW...OR 9 MILES NORTHEAST OF BUCHANAN DAM...MOVING EAST AT 30 MPH.

THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS
OF THE INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

&&

LAT...LON 3104 9823 3083 9823 3083 9850 3093 9851
      3094 9845 3095 9846 3099 9845 3102 9847
TIME...MOT...LOC 2336Z 267DEG 25KT 3091 9829

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 7:49 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Hays, Travis, Williamson	41 min
May 20, 8:04 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Hays, Travis	26 min
May 20, 8:27 PM CDT	Severe Thunderstorm Warning	EWX	Caldwell, Hays, Travis	23 min
May 20, 8:58 PM CDT	Severe Thunderstorm Warning	EWX	Hays, Travis	32 min
May 20, 8:59 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Lee, Travis, Williamson	61 min
May 20, 9:22 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Lee, Travis	38 min
May 20, 10:02 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell	43 min
May 20, 10:32 PM CDT	Severe Thunderstorm Warning	EWX	Caldwell, Guadalupe, Hays	43 min
May 21, 4:58 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Llano, Williamson	47 min
May 21, 5:44 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	46 min
May 21, 6:00 PM CDT	Areal Flood Advisory	EWX	Burnet, Llano	2 hr
May 21, 6:29 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	46 min
May 21, 6:52 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	38 min
May 21, 6:59 PM CDT	Tornado Warning	EWX	Burnet	31 min

Nearby

Severe Thunderstorm Warnings in Texas, 2011 Every 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.