Alert archive / Texas / Tornado Warnings in 2011

Tornado Warning 14, NWS Austin/San Antonio, TX

May 21, 2011Williamson County, Texas

NWS Austin/San Antonio, TX issued this tornado warning at May 21, 2011, 8:59 PM CDT for Williamson County, Texas. It was in force for 31 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, 8:59 PM CDT (01:59 UTC)
Expired: May 21, 2011, 9:30 PM CDT
In force: 31 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

County Williamson County, TX

The radar

The Ft Hood radar (KGRK), 37 km from the middle of the area, began a volume at 02:02 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, 9:00 PM CDT	TORNADO	1 Sse Andice, TX	NWS DAMAGE SURVEY CONFIRMS A TORNADO TOUCHED DOWN ABOUT 1 MILE SOUTHEAST OF ANDICE. THE TORNADO TRACKED APPROXIMATELY 1.5 MILES TO THE NORTHEAST. DAMAGE CONSISTED OF MAINLY TREE DAMAGE...DAMAGE TO CARPORTS...MOBILE HOME ROOFS...DECKS...AND OUTDOOR EQUIPMENT. I
May 21, 9:04 PM CDT	FUNNEL CLOUD	Andice, TX	ROTATING WALL CLOUD OVER THE CITY OF ANDICE.

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, 2.0 hours before the alert went out and 232 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.

846 
WFUS54 KEWX 220159
TOREWX
TXC491-220230-
/O.NEW.KEWX.TO.W.0014.110522T0159Z-110522T0230Z/

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

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN WILLIAMSON COUNTY...

* UNTIL 930 PM CDT.

* AT 857 PM CDT...NWS METEOROLOGISTS HAVE DETECTED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR ANDICE...OR ABOUT
  9 MILES NORTHWEST OF SERENADA...MOVING EAST AT 15 MPH.

* THE TORNADO WILL MOVE TOWARD HIGHWAY 195 EAST OF ANDICE.

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 3082 9769 3071 9774 3075 9788 3081 9784
TIME...MOT...LOC 0158Z 281DEG 12KT 3077 9782

$$

1 follow-up statement

940 
WWUS54 KEWX 220214
SVSEWX

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

TXC491-220230-
/O.CON.KEWX.TO.W.0014.000000T0000Z-110522T0230Z/
WILLIAMSON TX-
914 PM CDT SAT MAY 21 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 PM CDT FOR NORTH
CENTRAL WILLIAMSON COUNTY...

AT 911 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A TORNADO. 
THIS TORNADO WAS LOCATED OVER NORTHWESTERN WILLIAMSON COUNTY...OR 9
MILES NORTHWEST OF SERENADA...MOVING EAST AT 10 MPH.

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.

&&

LAT...LON 3082 9769 3076 9772 3077 9783 3081 9782
TIME...MOT...LOC 0214Z 255DEG 9KT 3080 9777

$$

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, 7:27 PM CDT	Tornado Warning	EWX	Burnet, Williamson	33 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, 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.