EF0 tornado, Nash to Medford, Oklahoma, May 10, 2010

1. EF065 to 85 mphthis tornado

   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 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

EF0

Date

May 10, 2010

Touchdown

3:39 PM CDT (20:39 UTC)

Path length

0.3 miles (0.5 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Grant County

Touchdown point

36.808, -98.031

Lift-off point

36.808, -98.031

Record number

1005101439-01

A significant outbreak of severe thunderstorms and tornadoes affected a large part of northern, central, and southern Oklahoma. Tornadoes were most numerous across central and southern Oklahoma, with significant damage occurring over many areas. |Severe thunderstorms erupted by mid afternoon across northern and western Oklahoma. Given the potent combination of ingredients in place, storms began to produce tornadoes quickly after initiation. Storm motions of 50 to 60 mph were common.||During the mid afternoon hours, severe weather was confined to northern Oklahoma. It was there a long track supercell storm produced tornadoes near the Kansas border - including one rated EF3 - from near Wakita to north of Braman.||The capping inversion that had delayed thunderstorm development into central Oklahoma weakened, allowing for explosive supercell development along the dry line along and west of the Interstate 35 corridor. Rapid development and intensification was common with the late afternoon storms, with storms becoming tornadic within a very short time after initiation. This round of storms would directly impact a large part of the Oklahoma City metro area at rush hour, and posed a significant threat to the area. The first tornado in this area occurred in Canadian County.||During the next several hours, tornadoes were clustered around the metro area, and at times there were multiple significant damaging tornadoes occurring simultaneously. Several of the tornadoes had long tracks. Damage from the tornadoes was substantial, with numerous structures, vehicles, trees and power poles/lines significantly damaged or destroyed. One of the more intense tornadoes moved across Lake Thunderbird east of Norman destroying numerous boats.||More storms developed across southwest and south central Oklahoma, and also quickly became tornadic. ||By 9 pm, 35 tornadoes had been reported. While the loss of three lives was tragic, the casualties could have been much higher given the storm's fast motions, their intensity, the time of day and the areas impacted. ||While exact monetary damage figures were not available, it is estimated that losses were in excess of $595 million. At least 450 sustained injuries, most of them minor. Unfortunately three people lost their lives. ||Note: The large number of injuries and tornadoes made it difficult to associate injuries with specific tornadoes. Injury numbers were included when we had confidence in the numbers. ||Note: The complex nature of storm evolutions and interactions made the job of classifying tornadoes difficult. This represents our best scientific assessment based on ground and aerial surveys, data from multiple radars, photographic and video evidence and anecdotal information.

Tornado #A1. A brief tornado was observed southwest of SH-132 and SH-11 by several storm chasers. No known damage occurred.

While the large multiple-vortex tornado (see entry for tornado A2 in Grant County) was developing southwest of Wakita, a storm chaser documented a satellite tornado that formed to the southeast of the primary tornado and moved northeast. This tornado persisted for about 30 seconds. No known damage occurred. Note: Although this tornado is the third tornado produced by supercell A, this tornado will be labeled as tornado A7 due to the late addition of this report and to preserve the continuity of labels of the other tornadoes produced by this supercell.

Tornado #A3. A brief tornado was observed southwest of the main tornado moving through Grant County. No damage was reported and the location is estimated.

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 20:13 UTC, 26 minutes before the tornado touched down, in force until 21:00 UTC.

The county was under a tornado watch, issued at 18:25 UTC and running to 01:17 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 19:59 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 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.

Enid/Woodring Municipal (WDG), 52 km from the path, in the two hours either side.

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

The Vance AFB radar (KVNX), 11 km away, was scanning. The volume nearest the touchdown began at 20:37 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 2010 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

70 more were confirmed in the United States that day.

All 71 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.