Alert archive / Texas / Tornado Warnings in 2011

Tornado Warning 12, NWS Houston/Galveston, TX

April 27, 2011Houston County, Trinity County, Texas

NWS Houston/Galveston, TX issued this tornado warning at Apr 27, 2011, 12:07 AM CDT for Houston County, Trinity County, Texas. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 27, 2011, 12:07 AM CDT (05:07 UTC)
Expired
Apr 27, 2011, 12:45 AM CDT
In force
38 min
Issued by
NWS Houston/Galveston, TX
Area
Storm-based polygon

Counties Houston County, TX, Trinity County, TX

The radar

The Ft Hood radar (KGRK), 182 km from the middle of the area, began a volume at 05:08 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 26, 9:42 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 5.1 hours before the alert went out and 221 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, Shreveport, LA at 00:00Z on 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2270 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, Shreveport, LA at 00:00Z on 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 281 square meters per square second.1939587897117Sfc1 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
2270 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
961 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
281 m²/s²
0-3 km storm-relative helicity
428 m²/s²
Significant tornado parameter
5.6
Supercell composite
23.5

Open this sounding in Storm Lab

The text

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

607 
WFUS54 KHGX 270507
TORHGX
TXC225-455-270545-
/O.NEW.KHGX.TO.W.0012.110427T0507Z-110427T0545Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1207 AM CDT WED APR 27 2011

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN HOUSTON COUNTY IN SOUTHEAST TEXAS...
  WESTERN TRINITY COUNTY IN SOUTHEAST TEXAS...

* UNTIL 1245 AM CDT

* AT 1205 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS TORNADO
  WAS LOCATED NEAR AUSTONIO... MOVING EAST AT 50 MPH.

* LOCATIONS IN THE TORNADO WARNING INCLUDE BUT ARE NOT LIMITED TO    
  AUSTONIO...LOVELADY...LATEXO AND CROCKETT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORNADOES AT NIGHT ARE ESPECIALLY DANGEROUS. DO NOT WAIT UNTIL YOU
SEE OR HEAR A TORNADO - TAKE COVER NOW!

A TORNADO WATCH IS IN EFFECT UNTIL 5 AM FOR THE WARNED AREA.

&&

PLEASE REPORT SEVERE WEATHER TO THE COUNTY SHERIFF...LOCAL POLICE...
OR DEPARTMENT OF PUBLIC SAFETY AND ASK THEM TO RELAY YOUR REPORT TO
THE NATIONAL WEATHER SERVICE.

LAT...LON 3143 9536 3131 9528 3100 9534 3103 9544
      3106 9544 3104 9548 3113 9579 3117 9574
      3122 9575 3124 9573 3127 9573 3133 9566
      3135 9568 3138 9569
TIME...MOT...LOC 0507Z 283DEG 44KT 3116 9568

$$

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 26, 10:03 PM CDTTornado WarningHGXHouston42 min
Apr 26, 10:43 PM CDTTornado WarningHGXHouston47 min
Apr 26, 11:15 PM CDTTornado WarningHGXHouston, Trinity45 min
Apr 26, 11:28 PM CDTTornado WarningHGXHouston, Madison, Trinity, Walker47 min
Apr 26, 11:55 PM CDTTornado WarningHGXHouston, Polk, Trinity50 min
Apr 27, 12:32 AM CDTTornado WarningHGXHouston, Trinity43 min
Apr 27, 12:55 AM CDTTornado WarningHGXPolk35 min
Apr 27, 4:22 AM CDTRed Flag WarningHGXAustin, Brazoria, Brazos, Burleson, Chambers, Colorado and 17 more16 hr

Nearby

Tornado Warnings in Texas, 2011Every tornado warning in 2011Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.