Alert archive / Louisiana / Tornado Warnings in 2012

Tornado Warning 17, NWS Shreveport, LA

March 21, 2012Jackson Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Mar 21, 2012, 5:41 AM CDT for Jackson Parish, Winn Parish, Louisiana. It was in force for 34 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 21, 2012, 5:41 AM CDT (10:41 UTC)
Expired
Mar 21, 2012, 6:15 AM CDT
In force
34 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties Jackson Parish, LA, Winn Parish, LA

The radar

The Shreveport radar (KSHV), 115 km from the middle of the area, began a volume at 10:42 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
Mar 20, 10:59 PM CDTTornado WatchSPC7 hr
Mar 21, 5:04 AM CDTTornado WatchSPC7 hr

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 10.7 hours before the alert went out and 244 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, Jackson, MS at 00:00Z on 2012-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 267 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, Jackson, MS at 00:00Z on 2012-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.193958Sfc1 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
267 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1256 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

247 
WFUS54 KSHV 211041
TORSHV
LAC049-127-211115-
/O.NEW.KSHV.TO.W.0017.120321T1041Z-120321T1115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
541 AM CDT WED MAR 21 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN JACKSON PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF JONESBORO...
  CENTRAL WINN PARISH IN NORTH CENTRAL LOUISIANA...
  THIS INCLUDES THE CITY OF WINNFIELD...

* UNTIL 615 AM CDT

* AT 537 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  WINNFIELD...MOVING NORTH AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  HUDSON...DODSON...HODGE...EAST HODGE...NORTH HODGE AND QUITMAN.

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.

&&

LAT...LON 3235 9275 3228 9242 3189 9261 3193 9282
TIME...MOT...LOC 1041Z 192DEG 35KT 3201 9269

$$

03
1 follow-up statement
302 
WWUS54 KSHV 211101
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
601 AM CDT WED MAR 21 2012

LAC127-211111-
/O.CAN.KSHV.TO.W.0017.000000T0000Z-120321T1115Z/
WINN LA-
601 AM CDT WED MAR 21 2012

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

LAT...LON 3216 9249 3215 9278 3235 9275 3228 9242
TIME...MOT...LOC 1101Z 192DEG 35KT 3220 9264

$$

LAC049-211115-
/O.CON.KSHV.TO.W.0017.000000T0000Z-120321T1115Z/
JACKSON LA-
601 AM CDT WED MAR 21 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 AM CDT FOR JACKSON
PARISH...

AT 559 AM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A TORNADO.  THIS TORNADO WAS
LOCATED NEAR JONESBORO...MOVING NORTH AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
HODGE...EAST HODGE AND NORTH HODGE

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 3216 9249 3215 9278 3235 9275 3228 9242
TIME...MOT...LOC 1101Z 192DEG 35KT 3220 9264

$$

03

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 20, 8:55 PM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Sabine, Winn10 hr
Mar 20, 9:02 PM CDTRiver Flood WarningSHVBienville, Bossier, Red River, Webster11 days
Mar 20, 9:03 PM CDTTornado WarningSHVNatchitoches27 min
Mar 20, 9:15 PM CDTFlash Flood WarningSHVBienville, De Soto, Red River9 hr
Mar 20, 9:24 PM CDTTornado WarningSHVNatchitoches36 min
Mar 20, 10:20 PM CDTTornado WarningSHVGrant, Natchitoches40 min
Mar 20, 10:50 PM CDTFlash Flood WarningSHVBossier, Claiborne, Webster10 hr
Mar 21, 1:52 AM CDTFlash Flood WarningSHVBienville, Jackson, Lincoln, Union8 hr
Mar 21, 2:49 AM CDTTornado WarningSHVGrant, Winn26 min
Mar 21, 3:14 AM CDTTornado WarningSHVJackson, Winn46 min
Mar 21, 6:16 AM CDTFlash Flood WarningSHVBienville, Red River3 hr
Mar 21, 6:47 AM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Red River, Sabine, Winn4 hr
Mar 21, 8:44 AM CDTFlash Flood WarningSHVClaiborne2 hr
Mar 21, 9:36 AM CDTFlash Flood WarningSHVUnion114 min
Mar 21, 10:51 AM CDTFlash Flood Warning EmergencySHVGrant, Natchitoches, Winn3 hr
Mar 21, 1:53 PM CDTAreal Flood WarningSHVNatchitoches6 hr

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; radar from the NEXRAD Level II archive.