Alert archive / Louisiana / Tornado Warnings in 2012

Tornado Warning 9, NWS Shreveport, LA

March 20, 2012De Soto Parish, Sabine Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Mar 20, 2012, 10:55 AM CDT for De Soto Parish, Sabine Parish, Louisiana. It was in force for 35 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 20, 2012, 10:55 AM CDT (15:55 UTC)
Expired
Mar 20, 2012, 11:30 AM CDT
In force
35 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties De Soto Parish, LA, Sabine Parish, LA

The radar

The Shreveport radar (KSHV), 64 km from the middle of the area, began a volume at 15:56 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, 9:46 AM CDTTornado WatchSPC7 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 3.9 hours before the alert went out and 68 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 2012-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 395 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 2012-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 221 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
395 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
754 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
221 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.1

Open this sounding in Storm Lab

The text

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

365 
WFUS54 KSHV 201555
TORSHV
LAC031-085-201630-
/O.NEW.KSHV.TO.W.0009.120320T1555Z-120320T1630Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
1055 AM CDT TUE MAR 20 2012

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL DE SOTO PARISH IN NORTHWEST LOUISIANA...
  THIS INCLUDES THE CITY OF MANSFIELD...
  EXTREME NORTHWESTERN SABINE PARISH IN NORTHWEST LOUISIANA...

* UNTIL 1130 AM CDT

* AT 1051 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 17 MILES
  SOUTHWEST OF MANSFIELD...MOVING NORTHEAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SOUTH
  MANSFIELD...GRAND CANE AND CARMEL.

LAT...LON 3178 9384 3180 9384 3182 9388 3187 9389
      3211 9381 3207 9356 3176 9379
TIME...MOT...LOC 1555Z 205DEG 33KT 3185 9383

$$

24
3 follow-up statements
949 
WWUS54 KSHV 201605
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1105 AM CDT TUE MAR 20 2012

LAC085-201615-
/O.CAN.KSHV.TO.W.0009.000000T0000Z-120320T1630Z/
SABINE LA-
1105 AM CDT TUE MAR 20 2012

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

LAT...LON 3185 9377 3186 9380 3186 9383 3190 9386
      3209 9380 3207 9356 3186 9372
TIME...MOT...LOC 1605Z 205DEG 33KT 3193 9378

$$

LAC031-201630-
/O.CON.KSHV.TO.W.0009.000000T0000Z-120320T1630Z/
DE SOTO LA-
1105 AM CDT TUE MAR 20 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1130 AM CDT FOR DE SOTO
PARISH...

AT 1101 AM CDT...A TORNADO WAS REPORTED.  THIS TORNADO WAS LOCATED 9
MILES SOUTHWEST OF SOUTH MANSFIELD...OR 11 MILES SOUTHWEST OF
MANSFIELD...MOVING NORTHEAST AT 40 MPH.

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

LAT...LON 3185 9377 3186 9380 3186 9383 3190 9386
      3209 9380 3207 9356 3186 9372
TIME...MOT...LOC 1605Z 205DEG 33KT 3193 9378

$$

24
695 
WWUS54 KSHV 201611
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1111 AM CDT TUE MAR 20 2012

LAC031-201630-
/O.CON.KSHV.TO.W.0009.000000T0000Z-120320T1630Z/
DE SOTO LA-
1111 AM CDT TUE MAR 20 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1130 AM CDT FOR DE SOTO
PARISH...

AT 1107 AM CDT...USING DOPPLER RADAR...NATIONAL WEATHER SERVICE
METEOROLOGISTS CONTINUED TO DETECT A TORNADO.  THIS TORNADO WAS 
LOCATED 6 MILES SOUTHWEST OF SOUTH...SOUTHWEST OF MANSFIELD...MOVING 
NORTHEAST AT 40 MPH.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3191 9368 3191 9375 3192 9380 3195 9384
      3209 9380 3207 9356
TIME...MOT...LOC 1612Z 205DEG 33KT 3199 9375

$$

24
195 
WWUS54 KSHV 201621
SVSSHV

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
1121 AM CDT TUE MAR 20 2012

LAC031-201630-
/O.CON.KSHV.TO.W.0009.000000T0000Z-120320T1630Z/
DE SOTO LA-
1121 AM CDT TUE MAR 20 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1130 AM CDT FOR DE SOTO
PARISH...

AT 1116 AM CDT...A TORNADO WAS REPORTED.  THIS TORNADO WAS LOCATED 
OVER DE SOTO PARISH...5 MILES NORTHEAST OF MANSFIELD...MOVING 
NORTHEAST AT 40 MPH.

LAT...LON 3200 9363 3204 9372 3208 9370 3207 9356
TIME...MOT...LOC 1621Z 205DEG 33KT 3209 9365

$$

24

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 19, 8:36 PM CDTRiver Flood WarningSHVCaddo6 days
Mar 20, 11:06 AM CDTRiver Flood WarningSHVBossier, Webster32 days
Mar 20, 11:16 AM CDTRiver Flood WarningSHVBienville, Bossier, Webster12 days
Mar 20, 11:17 AM CDTRiver Flood WarningSHVLincoln, Ouachita, Union7 days
Mar 20, 11:31 AM CDTTornado WarningSHVDe Soto, Natchitoches, Sabine29 min
Mar 20, 11:35 AM CDTSevere Thunderstorm WarningSHVNatchitoches, Sabine55 min
Mar 20, 12:10 PM CDTSevere Thunderstorm WarningSHVBienville, De Soto, Natchitoches, Red River, Sabine65 min
Mar 20, 12:30 PM CDTSevere Thunderstorm WarningSHVGrant, Natchitoches, Sabine, Winn60 min
Mar 20, 12:54 PM CDTTornado WarningSHVNatchitoches, Winn36 min
Mar 20, 1:04 PM CDTSevere Thunderstorm WarningSHVBienville, Jackson, Lincoln, Natchitoches, Red River, Winn41 min
Mar 20, 1:34 PM CDTSevere Thunderstorm WarningSHVBienville, Grant, Jackson, Natchitoches, Winn56 min
Mar 20, 3:03 PM CDTFlash Flood WarningSHVGrant, Natchitoches, Winn6 hr
Mar 20, 6:24 PM CDTFlash Flood WarningSHVNatchitoches, Sabine3 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.