EF4 Lone Grove tornado, Oklahoma, February 10, 2009

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 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 mphthis tornado

   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

EF4

Date

February 10, 2009

Touchdown

6:45 PM CST (00:45 UTC)

Lifted

7:43 PM CST (01:43 UTC)

On the ground

58 minutes

Path length

37.0 miles (59.5 km)

Path width

880 yards (805 m)

Deaths

8

Injuries

46

Property damage

$3.0 million

Counties

Jefferson, Montague, Love and Carter counties

Touchdown point

33.930, -97.620

Lift-off point

34.260, -97.113

Record number

0902101845-01

Thunderstorms developed early in the afternoon, from near the Lawton area, northeast toward the Oklahoma metro area. Thunderstorms became severe relatively quickly as they moved through Caddo and Grady counties, and began to show signs of rotation as they moved toward western Oklahoma City. One supercell thunderstorm spawned several tornadoes as it moved through western and northern Oklahoma. Sporadic damage was reported along its path, some of it significant as it moved through northern Oklahoma county and southern Logan county. Other supercells developed near the same areas of Caddo and Grady counties and moved northeast. Some locations received several rounds of very large hail through the afternoon. ||Later in the afternoon, a second area of thunderstorms developed over northern Texas. Several supercell thunderstorms developed and moved northeast toward the Red River. One supercell thunderstorm moved northeast over Clay county and northwest Montague county. A tornado developed as it moved into Jefferson county near the Red River. It continued northeast through western Love county and into Carter County. Significant damage was reported in and around the Lone Grove area and over the far north sides of Ardmore. There were eight fatalities in and around Lone Grove. The tornado crossed Interstate 35 and eventually crossed into southern Murray county. Wind damage was reported in Coal and Atoka counties. Minor injuries were reported with the Atoka county thunderstorms. Monetary damages were estimated.

This long track tornado developed over far southeast Jefferson County, near the Red River, and continued northeast into Love County crossing through rural farmland north of Courtney, Rubottom and Oswalt. The tornado then crossed into Carter County, with sporadic damage noted in the sparsely populated areas in the southwest part of the county. The tornado appeared to reach its maximum width and intensity as it approached and moved through Lone Grove. The tornado destroyed or severely damaged numerous mobile homes, homes and businesses in and around Lone Grove. Numerous mobile homes were completely obliterated with few recognizable pieces left. EF4 damage was noted at two locations, one in Lone Grove and the other in the Majestic Hills area north of Ardmore. Numerous vehicles were rolled or thrown, some for considerable distances. Six of the fatalities occurred in mobile homes and one in a well-built home that sustained EF4 damage. The eighth fatality occurred when a truck driving south on Interstate 35 was hit by the tornado killing the driver. ||The tornado continued northeast, with major damage reported in the Majestic Hills addition and crossing Interstate-35 about a mile and a half north of the Prairie Valley Road exit. At least eight homes and a small private school were destroyed in the Majestic Hills neighborhood. It moved through rural areas of Northeast Carter County to the east of Springer. Approximately 46 people were injured, with 14 seriously injured. Eight people died in the Lone Grove area. At least 114 homes were damaged or destroyed, with at least 3500 losing power in and around Carter county. Debris from this tornado was picked up as far away as Sulphur. Monetary damage estimates were not available.

The deaths

8 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.

26 minutes of warning. NWS FWD issued a tornado warning for this county at 00:19 UTC, 26 minutes before the tornado touched down, in force until 00:45 UTC.

The county was under a tornado watch, issued at 18:49 UTC and running to 03:35 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 Moderate Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:50 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 Norman radar (KTLX), 138 km away, was scanning. The volume nearest the touchdown began at 00:45 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 2009 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

9 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.