F1 tornado, Castle, Oklahoma, September 10, 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

September 10, 1999

Touchdown

6:47 PM CDT (23:47 UTC)

Path length

3.5 miles (5.6 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Property damage

$80,000

County

Okfuskee County

Touchdown point

35.520, -96.380

Lift-off point

35.470, -96.350

Record number

626

Summary of events for September 10 1999:Severe thunderstorms developed early on the afternoon of Sept. 10 as warm, moist low-level air returned following several days of cooler, drier weather. Severe weather initially developed over the Tulsa metro area with the emphasis shifting south to Haskell County by early evening. The afternoon convection then left an outflow boundary over northcentral Oklahoma that was the focus for more severe thunderstorms as an upper level disturbance approached in the evening. This second round of storms slipped southeast along the outflow boundary from Pawnee County to Okfuskee County. The worst storm of the day was the last storm of the day...a supercell that moved east-southeast along the outflow boundary in Okfuskee County, producing a damaging tornado, damaging baseball-sized hail, and 80 mph winds.

An F1 tornado touched down about 3 miles north of Castle, travelling approximately 3.5 miles southeast before lifting about 2 miles east of Castle. Along the way, this storm completely ripped the roof from one permanent wood-frame house about 2 miles northeast of Castle, and it blew the roof off of a mobile home located on OK Hwy 48 north of Castle near I.X.L. Another residence immediately to the south sustained minor damage when a tree fell on the corner of the house. The house's owner said that she witnessed a white funnel about 100 yards to the northeast. Several barns were completely destroyed, leaving only hay bales that were once covered by the barns.

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

20 minutes of warning. NWS TSA issued a tornado warning for this county at 23:27 UTC, 20 minutes before the tornado touched down, in force until 00:00 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 19:55 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 live radar over the trackEvery 1999 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.