Alert archive / Louisiana / Tornado Warnings in 2012

Tornado Warning 8, NWS Shreveport, LA

March 11, 2012Caldwell Parish, LaSalle Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Mar 11, 2012, 7:31 PM CDT for Caldwell Parish, LaSalle Parish, Winn Parish, Louisiana. It was in force for 44 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
Mar 11, 2012, 7:31 PM CDT (00:31 UTC)
Expired
Mar 11, 2012, 8:15 PM CDT
In force
44 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties Caldwell Parish, LA, LaSalle Parish, LA, Winn Parish, LA

The watch it was issued in

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

IssuedProductOfficeLasted
Mar 11, 6:42 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 0.5 hours before the alert went out and 171 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 2012-03-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 129 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 2012-03-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 266 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
129 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
778 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
266 m²/s²
0-3 km storm-relative helicity
303 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

288 
WFUS54 KSHV 120031
TORSHV
LAC021-059-127-120115-
/O.NEW.KSHV.TO.W.0008.120312T0031Z-120312T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
731 PM CDT SUN MAR 11 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  CALDWELL PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF COLUMBIA...
  NORTHWESTERN LA SALLE PARISH IN NORTH CENTRAL LOUISIANA...
  EAST CENTRAL WINN PARISH IN NORTH CENTRAL LOUISIANA...

* UNTIL 815 PM CDT

* AT 730 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO ABOUT 3 MILES SOUTHWEST 
  OF OLLA...OR 20 MILES EAST OF WINNFIELD...MOVING NORTHEAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  CLARKS AND GRAYSON...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. TAKE COVER NOW! IF YOU WAIT
TO SEE OR HEAR IT COMING...IT MAY BE TOO LATE TO GET TO A SAFE PLACE.

&&

LAT...LON 3207 9192 3203 9189 3199 9189 3177 9233
      3191 9245 3225 9200 3220 9197 3218 9197
      3217 9191 3212 9186 3209 9186
TIME...MOT...LOC 0030Z 230DEG 32KT 3190 9229

$$

15
1 follow-up statement
192 
WWUS54 KSHV 120056
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
756 PM CDT SUN MAR 11 2012

LAC127-120103-
/O.CAN.KSHV.TO.W.0008.000000T0000Z-120312T0115Z/
WINN LA-
756 PM CDT SUN MAR 11 2012

...THE TORNADO WARNING FOR WINN PARISH IS CANCELLED...

THE SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO HAS EXITED EXTREME 
EASTERN WINN PARISH.

LAT...LON 3207 9192 3203 9189 3199 9189 3177 9233
      3197 9231 3225 9200 3220 9197 3218 9197
      3217 9191 3212 9186 3209 9186
TIME...MOT...LOC 0053Z 225DEG 33KT 3205 9213

$$

LAC021-059-120115-
/O.CON.KSHV.TO.W.0008.000000T0000Z-120312T0115Z/
LA SALLE LA-CALDWELL LA-
756 PM CDT SUN MAR 11 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR CALDWELL
AND LA SALLE PARISHES...

AT 756 PM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A TORNADO.  THIS TORNADO WAS
LOCATED NEAR CLARKS...OR 8 MILES SOUTHWEST OF COLUMBIA...MOVING
NORTHEAST AT 40 MPH. ANOTHER THUNDERSTORM EXHIBITING ROTATION 
WAS INDICATED NEAR URANIA...ALSO MOVING NORTHEAST AT 40 MPH. 
THIS STORM WILL AFFECT THE OLLA COMMUNITY BY 8 PM.  

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GRAYSON

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. TAKE COVER NOW! IF YOU WAIT
TO SEE OR HEAR IT COMING...IT MAY BE TOO LATE TO GET TO A SAFE PLACE.

&&

LAT...LON 3207 9192 3203 9189 3199 9189 3177 9233
      3197 9231 3225 9200 3220 9197 3218 9197
      3217 9191 3212 9186 3209 9186
TIME...MOT...LOC 0053Z 225DEG 33KT 3205 9213

$$

15

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 12, 6:56 AM CDTRiver Flood WarningSHVWebster20 days

Nearby

Tornado Warnings in Louisiana, 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.