EF1 tornado, Perkins to Stillwater, 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 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 10, 2009

Touchdown

3:39 PM CST (21:39 UTC)

Lifted

3:59 PM CST (21:59 UTC)

On the ground

20 minutes

Path length

9.6 miles (15.4 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Payne County

Touchdown point

35.953, -97.183

Lift-off point

36.070, -97.105

Record number

0902101539-01

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.

Sporadic damage was observed along the tornado's path, including damage to a grain silo and outbuildings, and snapped trees. The most significant damage occurred near the intersection of Highway 33 and South Range Road in far southern Payne County. At this location a well-built barn was completely destroyed, and several other outbuildings were damaged. A cow and calf were killed in the barn. Sporadic damage was observed as the tornado continued northeast before dissipating about one mile south of the Stillwater city limits. Monetary damage estimates were not available.

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

26 minutes of warning. NWS OUN issued a tornado warning for this county at 21:13 UTC, 26 minutes before the tornado touched down, in force until 21:45 UTC.

The county was under a tornado watch, issued at 18:49 UTC and running to 01:49 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. 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), 76 km away, was scanning. The volume nearest the touchdown began at 21:38 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 OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma 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.