EF1 tornado, Stillwater, Oklahoma, May 19, 2010

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 mphthis tornado

   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

EF1

Date

May 19, 2010

Touchdown

6:03 PM CDT (23:03 UTC)

Lifted

6:36 PM CDT (23:36 UTC)

On the ground

33 minutes

Path length

10.6 miles (17.0 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

County

Payne County

Touchdown point

36.120, -97.329

Lift-off point

36.148, -97.143

Record number

1005191703-01

A large storm system moved through the southern and central Plains during the morning and afternoon of the 19th. Thunderstorms, some of them severe, had developed over the Texas panhandle and moved east into northwest and north central Oklahoma during the early morning hours. Additional development, aided by the low-level jet, occurred into parts of central Oklahoma, north of a warm front that was slowly moving north to near Interstate 40. ||By mid afternoon, the well-defined front was located from parts of west-central into central Oklahoma, just north of the Oklahoma City metro area. Two thunderstorms developed near and along the front, one over Roger Mills and Dewey counties, and the other over northern Blaine county. The storms quickly became tornadic, with the first tornado of the day occurring north of Leedey in Dewey county. Another tornado, and probably the most photographed one of the day, occurred just north of Hennessey. Tornadoes, most of them brief in duration, and large hail continued across western and central Kingfisher county, and across northern Logan, southeast Garfield, and Payne counties. Another thunderstorm developed further east along the dry line later in the afternoon, and the storm eventually produced a tornado west of Prague in Lincoln county. ||Finally, two supercell thunderstorms developed further south along the dry line that moved into central Oklahoma. Although both showed significant rotation on radar, only the supercell that moved from Stephens through Murray counties produced tornadoes. Two tornadoes were reported, one just southeast of Wynnewood and another north of Sulphur.||Additional severe thunderstorms developed across southern Oklahoma, but the main impacts had shifted from tornadoes to large hail and very heavy rainfall. By the time it was all said and done, five main supercells had occurred over parts of western and central Oklahoma, producing at least nine tornadoes. Widespread significant damage did not occur due to the location/short duration of the tornadoes, and only three minor injuries were reported.

Radar and video evidence showed a tornado moved from just east of Interstate 35, over Lake Carl Blackwell, to five miles west of Stillwater. Most of the damage occurred at Range and McElroy Roads. Much of the damage was confined to trees. However, a large wooden barn sustained damage, as well as a tin roof taken off a home, and other outbuildings were damaged. Monetary damage estimates were not available.

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

37 minutes of warning. NWS OUN issued a tornado warning for this county at 22:26 UTC, 37 minutes before the tornado touched down, in force until 23:30 UTC.

The county was under a tornado watch, issued at 19:10 UTC and running to 03:00 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 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 19:58 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.

Stillwater Municipal (SWO), 14 km from the path, in the two hours either side.

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

The Norman radar (KTLX), 89 km away, was scanning. The volume nearest the touchdown began at 23:01 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

24 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.