EF2 tornado, Harmon, Oklahoma, May 5, 2007

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 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. 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

EF2

Date

May 5, 2007

Touchdown

9:36 PM CDT (02:36 UTC)

Lifted

9:58 PM CDT (02:58 UTC)

On the ground

22 minutes

Path length

7.3 miles (11.7 km)

Path width

300 yards (274 m)

Deaths

0

Injuries

1

Property damage

$612,000

County

Ellis County

Touchdown point

35.889, -99.774

Lift-off point

35.943, -99.746

Record number

0705052036-01

An upper level storm system moved slowly into south central Colorado during the afternoon. A dry line had become established and was located along the Oklahoma and Texas panhandle border. Also, favorable upper level winds were rotating around the upper level storm system, crossing the dryline over western Oklahoma. As the afternoon progressed, convergence along the dryline became maximized over this area. Thunderstorms developed during the afternoon hours and they quickly became supercells. Two of the supercells produced several tornadoes. The northern tornadic storm produced five tornadoes from southwest of Roll to just east of Arnett. The southern tornadic storm also produced five tornadoes in Oklahoma from near Sweetwater to near Sharon. Large hail was also observed. The supercells moved northeast out of Oklahoma during the late evening hours. Monetary values for the tornado damage were estimated.

This tornado developed 4 miles north-northeast of Roll in northern Roger Mills County and crossed the Canadian River into southern Ellis County at 9:36 pm CDT. Two houses and two mobile homes were destroyed in the Packsaddle area of southern Ellis County to the east of US Highway 283 (about 18 miles south-southwest of Harmon), and a roof was removed from another mobile home. At least one of these homes suffered a complete removal of the roof and some damage to the exterior walls. Several cars were damaged or destroyed, as well as trees and power lines. Monetary values were estimated.

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

21 minutes of warning. NWS OUN issued a tornado warning for this county at 02:15 UTC, 21 minutes before the tornado touched down, in force until 03:15 UTC.

The county was under a tornado watch, issued at 17:20 UTC and running to 02:58 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 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:59 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 Vance AFB radar (KVNX), 173 km away, was scanning. The volume nearest the touchdown began at 02:37 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 2007 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

96 more were confirmed in the United States that day.

All 97 of them

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.