F1 tornado, Ft Gibson, 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 mphthis tornado

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

3. F2113 to 157 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. 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

F1

Date

June 1, 1999

Touchdown

6:16 PM CDT (23:16 UTC)

Path length

2.3 miles (3.7 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$2.0 million

County

Muskogee County

Touchdown point

35.780, -95.280

Lift-off point

35.770, -95.300

Record number

1101

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.

An F1 tornado touched down near the Port of Muskogee and moved south for 2.25 miles, lifting just south of Three Forks Park. This tornado destroyed three structures belonging to one business, destroyed two business outbuildings at 3-Forks Park, caused minor damage to one business under construction, and affected eight single family dwellings. The most newsworthy result of this tornado was damage directly inflicted upon the OG&E electrical generation plant. The tornado damaged a coal conveyor belt and a cooling tower. The damage was enough to shut down two of the plant's four coal-powered generating units. At the Fansteel plant, six buildings were torn down by the tornado, causing up to $1.5 million damage there.

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

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), 15 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.