Alert archive / Texas / Tornado Warnings in 2011

Tornado Warning 9, NWS Austin/San Antonio, TX

May 21, 2011Burnet County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this tornado warning at May 21, 2011, 7:27 PM CDT for Burnet County, Williamson County, Texas. It was in force for 33 min. 1 report 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, 7:27 PM CDT (00:27 UTC)
Expired: May 21, 2011, 8:00 PM CDT
In force: 33 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

Counties Burnet County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 64 km from the middle of the area, began a volume at 00:29 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, 7:32 PM CDT	FUNNEL CLOUD	Bertram, TX	SPOTTER NEAR BERTRAM SEES A WALL CLOUD ROTATING.

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 00:00Z, 0.5 hours before the alert went out and 235 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: 3908 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 978 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 3.2
Supercell composite: 16.6

Open this sounding in Storm Lab

The text

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

330 
WFUS54 KEWX 220027
TOREWX
TXC053-491-220100-
/O.NEW.KEWX.TO.W.0009.110522T0027Z-110522T0100Z/

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

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL BURNET COUNTY...
  EXTREME WEST CENTRAL WILLIAMSON COUNTY...

* UNTIL 800 PM CDT.

* AT 727 PM CDT...NWS METEOROLOGISTS HAVE DETECTED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SHADY GROVE...OR
  ABOUT 6 MILES NORTHEAST OF BURNET...MOVING EAST AT 10 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE BERTRAM...JOPPA AND BRIGGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN A MOBILE HOME OR VEHICLE...GET OUT AND GO TO A STURDY
SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH
OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

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

&&

LAT...LON 3087 9791 3071 9799 3077 9820 3087 9818
TIME...MOT...LOC 0027Z 279DEG 11KT 3080 9814

$$

1 follow-up statement

136 
WWUS54 KEWX 220036
SVSEWX

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

TXC053-491-220100-
/O.CON.KEWX.TO.W.0009.000000T0000Z-110522T0100Z/
BURNET TX-WILLIAMSON TX-
736 PM CDT SAT MAY 21 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR EXTREME
WEST CENTRAL WILLIAMSON AND CENTRAL BURNET COUNTIES...

AT 733 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A TORNADO. 
THIS TORNADO WAS LOCATED NEAR SHADY GROVE...OR NEAR BERTRAM...MOVING
SOUTHEAST AT 20 MPH.

RESIDENTS IN BERTRAM SHOULD TAKE COVER IMMEDIATELY!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS ON THE LOWEST FLOOR OF A
BUILDING IN AN INTERIOR HALLWAY...BATHROOM...OR CLOSET. COVER
YOURSELF WITH BLANKETS...PILLOWS OR EVEN A MATTRESS FOR BETTER
PROTECTION.

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

&&

LAT...LON 3083 9793 3071 9799 3076 9816 3084 9813
TIME...MOT...LOC 0035Z 293DEG 18KT 3077 9809

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 7:10 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Travis, Williamson	50 min
May 21, 7:44 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	46 min
May 21, 7:50 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Llano	40 min
May 21, 7:59 PM CDT	Tornado Warning	EWX	Burnet, Williamson	31 min
May 21, 8:08 PM CDT	Areal Flood Advisory	EWX	Burnet, Williamson	112 min
May 21, 8:11 PM CDT	Tornado Warning	EWX	Burnet, Llano	34 min
May 21, 8:27 PM CDT	Severe Thunderstorm Warning	EWX	Williamson	48 min
May 21, 8:27 PM CDT	Tornado Warning	EWX	Williamson	33 min
May 21, 8:32 PM CDT	Severe Thunderstorm Warning	EWX	Burnet	43 min
May 21, 8:44 PM CDT	Tornado Warning	EWX	Burnet	31 min
May 21, 8:59 PM CDT	Tornado Warning	EWX	Williamson	31 min
May 21, 9:14 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	46 min

Nearby

Tornado Warnings in Texas, 2011 Every tornado warning in 2011 Tornadoes 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.