EF0 tornado, Clear Lake to Forgan, Oklahoma, May 28, 2013

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 28, 2013

Touchdown

3:08 PM CDT (20:08 UTC)

Lifted

3:11 PM CDT (20:11 UTC)

On the ground

3 minutes

Path length

0.8 miles (1.3 km)

Path width

25 yards (23 m)

Deaths

0

Injuries

0

County

Beaver County

Touchdown point

36.800, -100.330

Lift-off point

36.810, -100.322

Record number

1305281408-01

2 damage points were recorded along this path by NWS AMA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

A severe weather outbreak brought hail, damaging winds, and tornadoes to portions of the Oklahoma Panhandle from the afternoon of the 28th into the early morning hours of the 29th. The morning upper air analysis on the 28th showed a mid-level shortwave trough rotating around the base of a longwave trough situated from Idaho to Arizona. At the surface, a dryline was situated from the northeastern Oklahoma Panhandle to the southwestern Texas Panhandle. The 6 AM CST upper air sounding from Amarillo showed a low level capping inversion with significant elevated instability. Also deep layer shear was primed for the development of discrete supercells. By noon, the northern portion of the dryline had moved into south central Kansas before stretching back into the southwestern Texas Panhandle, as instability values increased across the area. At this time, the combination of a residual cold frontal boundary and the dryline helped to form two landspout tornadoes as thunderstorms developed along the dryline across Beaver County. These tornadoes formed over undeveloped land and produced little damage.||During the late evening the dryline began to retreat westward as the nocturnal low level jet transported moisture from the Gulf of Mexico northwestward. This allowed the remnants of a supercell that brought severe weather to the Texas Panhandle to move into Beaver County. These storms produced isolated downbursts while decaying over the county.

A landspout tornado formed during the afternoon hours of the 28th. Eye-witness accounts described the landspout as a brief spin-up that started from the ground and connected with the base of a developing thunderstorm. Several pictures were taken by the eye-witnesses from U.S. Highway 83 approximately 4 miles south of Beaver (Beaver County). A National Weather Service survey team, using the eye-witness accounts, located the track of this landspout. Very little damage was evident given the landspout formed over grasslands and away from developed real estate. The max estimated wind speed was 60 mph. No injuries or fatalities were associated with this landspout tornado.

A landspout tornado formed during the afternoon hours of the 28th near the town of Beaver (Beaver County). Eye-witness accounts stated the landspout developed north of the Beaver Sand Dunes State Park east of State Road 23. A National Weather Service survey team located the start of the track approximately 4 miles north of Beaver (Beaver County). Eye-witness reported that the landspout traveled to the northwest, crossed State Road 23, and traveled west of State Road 23 before dissipating approximately 5 miles north-northwest of Beaver (Beaver County). The survey team verified the eye-witness accounts and noted that little damage was evident since the landspout formed over undeveloped grassland. The estimated max wind speed with this tornado was 60 mph. No injuries or fatalities were associated with this landspout.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 19:58 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:38 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.

Perryton/Ochiltree County Apt (PYX), 58 km from the path, in the two hours either side.

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

The Dodge City radar (KDDC), 111 km away, was scanning. The volume nearest the touchdown began at 20:10 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 2013 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.