Alert archive / Texas / Tornado Warnings in 2012

Tornado Warning 35, NWS Shreveport, LA

April 11, 2012Nacogdoches County, Shelby County, Texas

NWS Shreveport, LA issued this tornado warning at Apr 11, 2012, 4:06 PM CDT for Nacogdoches County, Shelby County, Texas. It was in force for 39 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 11, 2012, 4:06 PM CDT (21:06 UTC)
Expired
Apr 11, 2012, 4:45 PM CDT
In force
39 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties Nacogdoches County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 93 km from the middle of the area, began a volume at 21:08 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 nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 9.1 hours before the alert went out and 100 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 12:00Z on 2012-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1015 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 12:00Z on 2012-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.19395878Sfc1 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
1015 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
833 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

060 
WFUS54 KSHV 112106
TORSHV
TXC347-419-112145-
/O.NEW.KSHV.TO.W.0035.120411T2106Z-120411T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
406 PM CDT WED APR 11 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN NACOGDOCHES COUNTY IN EASTERN TEXAS...
  WEST CENTRAL SHELBY COUNTY IN EASTERN TEXAS...

* UNTIL 445 PM CDT

* AT 403 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR STOCKMAN...
  MOVING SOUTHEAST AT 10 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  ARCADIA AND JERICHO...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WARNING MEANS THAT STRONG ROTATION HAS BEEN DETECTED IN THE
STORM. A TORNADO MAY ALREADY BE ON THE GROUND...OR IS EXPECTED TO
DEVELOP SHORTLY. IF YOU ARE IN THE PATH OF THIS DANGEROUS STORM...
MOVE INDOORS AND TO THE LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM
WINDOWS. IF DRIVING...DO NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE 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 3171 9421 3166 9439 3176 9448 3181 9440
TIME...MOT...LOC 2106Z 318DEG 7KT 3174 9442

$$

06
2 follow-up statements
255 
WWUS54 KSHV 112133
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
433 PM CDT WED APR 11 2012

TXC347-112139-
/O.CAN.KSHV.TO.W.0035.000000T0000Z-120411T2145Z/
NACOGDOCHES TX-
433 PM CDT WED APR 11 2012

...THE TORNADO WARNING FOR NACOGDOCHES COUNTY IS CANCELLED...

LAT...LON 3169 9427 3166 9439 3171 9441 3175 9435
TIME...MOT...LOC 2129Z 322DEG 8KT 3169 9437

$$

TXC419-112145-
/O.CON.KSHV.TO.W.0035.000000T0000Z-120411T2145Z/
SHELBY TX-
433 PM CDT WED APR 11 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR SHELBY
COUNTY...

AT 428 PM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE 
METEOROLOGISTS CONTINUED TO DETECT A SEVERE THUNDERSTORM CAPABLE OF 
PRODUCING A TORNADO.  THIS THUNDERSTORM WAS LOCATED OVER SHELBY 
COUNTY...ABOUT 4 MILES SOUTHWEST OF ARCADIA...MOVING SOUTHEAST 
AT 10 MPH.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 3169 9427 3166 9439 3171 9441 3175 9435
TIME...MOT...LOC 2129Z 322DEG 8KT 3169 9437

$$

06
783 
WWUS54 KSHV 112145
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
445 PM CDT WED APR 11 2012

TXC419-112154-
/O.EXP.KSHV.TO.W.0035.000000T0000Z-120411T2145Z/
SHELBY TX-
445 PM CDT WED APR 11 2012

...THE TORNADO WARNING FOR SHELBY COUNTY WILL EXPIRE AT 445 PM CDT...

THE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO HAS DECREASED IN 
INTENSITY...BUT MAY PULSE UP LATER. THIS STORM WILL BE WATCHED.

LAT...LON 3169 9427 3166 9439 3171 9441 3175 9435
TIME...MOT...LOC 2144Z 322DEG 8KT 3166 9435

$$

06

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 8:17 PM CDTSevere Thunderstorm WarningSHVBowie43 min
Apr 10, 9:40 PM CDTSevere Thunderstorm WarningSHVBowie35 min
Apr 11, 2:50 PM CDTTornado WarningSHVRusk40 min
Apr 11, 3:22 PM CDTTornado WarningSHVRusk31 min
Apr 11, 4:01 PM CDTTornado WarningSHVSabine, San Augustine44 min

Nearby

Tornado Warnings in Texas, 2012Every tornado warning in 2012Tornadoes in 2012

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.