F2 tornado, Checotah to Onapa, Oklahoma, June 1, 1999

1. F040 to 72 mph

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

2. F173 to 112 mph

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

3. F2113 to 157 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. F3158 to 206 mph

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

5. F4207 to 260 mph

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

6. F5261 to 318 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

F2

Date

June 1, 1999

Touchdown

6:57 PM CDT (23:57 UTC)

Path length

2.0 miles (3.2 km)

Path width

0 yards (0 m)

Deaths

0

Injuries

0

Property damage

$40,000

County

McIntosh County

Touchdown point

35.420, -95.530

Lift-off point

35.380, -95.530

Record number

1104

Summary of events for the afternoon and evening of June 1 1999:A cold front moving in from the northwest moved into an extremely unstable air mass on the afternoon of June 1. Along the front, an isolated supercell thunderstorm developed around the Pryor/Locust Grove area and then moved in a slow and unusual south-southwest direction. This storm produced very large hail in addition to several strong tornadoes. This storm also produced eastern Oklahoma's first killer tornado in at least half of a decade.

The F1 tornado described here was the first of two tornadoes to touch down in Checotah on the evening of June 1. Each tornado was spawned from the same parent thunderstorm. The first tornado travelled through a more densely populated area of Checotah and therefore caused more damage, even though the second tornado had a stronger intensity rating of F3 on the Fujita scale. The first tornado touched down at 646 PM CDT on the west side of Checotah near the intersection of US Hwys 69 and 266 (West Gentry Avenue). The tornado then moved southeast through town, eventually lifting near the 700 block of South Broadway Street at 649 PM CDT. Spotters described the tornado as having a rope-like appearance. Damage assessments in Checotah combined the effects of the first and second tornadoes. Overall for both tornadoes, there were a total of 75 homes that had some sort of damage. Here is the breakdown: six homes were destroyed, 21 homes sustained major damage, 48 homes sustained minor damage, three businesses sustained minor damage, and 28 head of cattle were killed. All of the business damage occurred with the first tornado. Most notably, a Wal-Mart near US Hwys 69 and 266 sustained roof and window damage, while a Pizza Hut on South Broadway Street sustained roof damage. In addition, numerous trees were blown down, with some trees falling onto vehicles and homes.

The F3 tornado described here was the second of two tornadoes to touch down in the Checotah area on the evening of June 1. Both tornadoes were spawned from the same parent thunderstorm. Even though this tornado had a stronger F-rating than the first, it caused less widespread damage since it travelled through a less densely populated area. The second tornado touched down on the southeast side of Checotah near I-40 and Grapevine Road at 650 PM CDT. The tornado travelled southeast for 4.5 miles and then lifted at 706 PM CDT.Damage assessments in Checotah combined the effects of the first and second tornadoes. For details of the damage assessment, see the third paragraph of the narrative for the Tornado entry immediately preceding this entry. This tornado, the second of the two, was rated an F3 based based on the near-complete destruction of a farm house 3 to 4 miles southeast of Checotah.

Spotters reported a tornado touchdown in open rangeland, moving due south for about 2 miles. Along the way, this tornado killed 28 head of cattle when they were hurled into a fence line. This tornado also caused minor damage to a home near Onapa.

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

33 minutes of warning. NWS TSA issued a tornado warning for this county at 23:24 UTC, 33 minutes before the tornado touched down, in force until 00:30 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 16:40 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.

Muskogee/Davis Field (MKO), 32 km from the path, in the two hours either side.

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

The live radar over the trackEvery 1999 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

30 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.