EF1 tornado, Oak Grove Roberts Ar to Kilbourne, Louisiana, February 24, 2011

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF1

Date

February 24, 2011

Touchdown

7:25 PM CST (01:25 UTC)

Lifted

7:30 PM CST (01:30 UTC)

On the ground

5 minutes

Path length

6.5 miles (10.5 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$750,000

County

West Carroll Parish

Touchdown point

32.976, -91.431

Lift-off point

32.999, -91.322

Record number

1102241925-01

A line of severe thunderstorms tracked from west to east across the ArkLaMiss region on the evening of February 24th. These storms were prolific wind producers, with measured wind gusts over 50 mph common in areas along and north of the I-20 corridor. As a result, widespread wind damage occurred over portions of southeastern Arkansas, northeastern Louisiana, and northern portions of central Mississippi. Downed trees and power lines were reported across several counties along with some minor structural damage in a few areas. In addition, embedded areas of circulation developed within the squall line. Two tornadoes were confirmed with these areas. The first was an EF-1 that tracked across northern West Carroll Parish, and the other was an EF-2 that tracked from northern Issaquena County into northern Sharkey County.

The tornado first touched down near the intersection of Highways 585 and 835 in the northwest part of West Carroll Parish. A grain truck was overturned first. Significant damage occurred to the roof of a church and minor damage occurred to the nearby parsonage. Then, the tornado knocked down a very large tree, which fell on a shed and the corner of a house. Two people narrowly escaped harm from this falling tree. As the tornado continued to move east-northeast, it destroyed a small shed, damaged a larger shed, and blew out some windows of a house. A large antenna was also significantly bent over. A travel trailer was turned about 45 degrees into a garage. The next structure the tornado encountered was a double-wide trailer, which had a large part of the roof blown off. Finally, another trailer was turned over in Kilbourne. Numerous trees were snapped and uprooted along the path. Five homes were also damaged. Maximum winds were around 95 mph.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a tornado watch, issued at 00:05 UTC and running to 02:02 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Slight Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 00:55 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Bastrop (BQP), 54 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Jackson/Brandon,MS radar (KDGX), 152 km away, was scanning. The volume nearest the touchdown began at 01:25 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2011 tornado in LouisianaEvery tornado in Louisiana since 1950Warnings in force in Louisiana nowThe forecast where you are

12 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.