EF1 tornado, Umpire to Mineola, Arkansas, April 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

April 24, 2011

Touchdown

10:54 PM CDT (03:54 UTC)

Lifted

10:59 PM CDT (03:59 UTC)

On the ground

5 minutes

Path length

3.4 miles (5.5 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$70,000

County

Howard County

Touchdown point

34.280, -94.047

Lift-off point

34.322, -94.016

Record number

1104242154-01

6 damage points were recorded along this path by NWS SHV, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 95 mph.

• .large limbs off of trees.
• .Large trees snapped in half.
• .Large portion of roof removed. Large trees uprooted along with large limbs snapped off. Large storage building destroyed. Adjacent chicken houses with moderate damage. Damage width 50-75 yards wide.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A stationary front was located across Southeast Oklahoma during the late evening and overnight hours of April 24th. Ahead of the boundary...a very unstable airmass was in place with an abundance of moisture pooling ahead of the frontal boundary. Strong shear was in place such that severe thunderstorms developed across north central Texas into southern and eastern Oklahoma as well as southwest Arkansas. These storms produced strong and damaging wind gusts across Southeast Oklahoma and a tornado was reported across the extreme northern portion of Howard County, Arkansas.

An NWS Storm Survey Team concluded that the damage across northern Howard County, Arkansas was consistent with an EF1 tornado. The tornado first touched down just northeast of Umpire, Arkansas along SR 84 where a large tree was snapped. The storm continued in a north northeast trajectory moving parallel to SR 84 snapping a few trees along its path as it moved towards the community of Mineola. The tornado did its worst damage just before lifting on Midway Road. The tornado hit a brick house where nearly half of the roof was completely removed. A large storage building was completely destroyed along with severe damage to an adjacent chicken house. Large trees were also uprooted adjacent to the dwelling. Estimated wind speeds were 90-100 mph at this point.

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. One was issued for the county at another hour that day.

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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:54 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.

The Western Arkansas radar (KSRX), 114 km away, was scanning. The volume nearest the touchdown began at 03:56 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 ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are

10 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.