EF2 tornado, Locust Grove to Rose, Oklahoma, August 10, 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 mph

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

3. EF2111 to 135 mphthis tornado

   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

EF2

Date

August 10, 2011

Touchdown

3:32 AM CDT (08:32 UTC)

Lifted

3:39 AM CDT (08:39 UTC)

On the ground

7 minutes

Path length

5.0 miles (8.0 km)

Path width

400 yards (366 m)

Deaths

1

Injuries

2

Counties

Mayes and Cherokee counties

Touchdown point

36.139, -95.138

Lift-off point

36.188, -95.073

Record number

1108100232-01

13 damage points were recorded along this path by NWS TSA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 125 mph.

• two trees were uprooted and fell onto a mobile home
• tied down with a number of concrete runners
• several large hardwood trees were uprooted to the northwest
• 2 large hardwood trees were uprooted onto a mobile home, which had its tiedowns snapped, lifted, and shifted off its piers

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

Strong to severe thunderstorms developed during the early morning hours of August 10th near a stationary frontal boundary that extended across eastern Oklahoma. Strong, damaging winds occurred across much of eastern Oklahoma as these storms moved across the region as well as a tornado.

This is the first of three segments of this tornado. The tornado developed on the leading edge of a short convective line of thunderstorms that wasn't undercut by cold outflow. It moved northeast uprooting and snapping a number of large trees within this segment in Mayes County and then moved into the extreme northwestern corner of Cherokee County. Based on the tree damage, maximum estimated wind in this segment of the tornado was about 105 mph.

This is the second of three segments of this tornado. The tornado tracked northeast across the extreme northwestern corner of Cherokee County, uprooting and snapping numerous trees. Based on the tree damage, maximum estimated wind in this segment of the tornado was about 105 mph. The tornado continued northeastward into Mayes County.

This is the third of three segments of this tornado. As the tornado crossed back into Mayes County, it destroyed a double wide mobile home and damaged a single wide mobile home just north of the E590 Road. A woman was killed in the double wide mobile home and two people were injured in the other mobile home. Trees were uprooted and snapped and debris from the double wide mobile home was transported several hundred yards downstream. The tornado damaged another mobile home south of the E580 Road where it destroyed a greenhouse. Numerous trees were uprooted and snapped along the path until the tornado dissipated just south of the E570 Road. Based on this damage, maximum estimated wind in this segment of the tornado was about 125 mph. ||August is one of the least active months for tornadoes in this part of the country so the intensity of this tornado was even more unusual. In fact, this is only the 4th strong tornado (EF-2 or EF-3) that has been confirmed in eastern Oklahoma since 1950.

The deaths

1 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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 severe thunderstorm watch, issued at 08:15 UTC and running to 10:13 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. The outlook in force was issued at 05:57 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.

Tahlequah Municipal (TQH), 28 km from the path, in the two hours either side.

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

The Tulsa radar (KINX), 41 km away, was scanning. The volume nearest the touchdown began at 08:32 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 OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

1 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.