EF0 tornado, Littlefield, Texas, April 21, 2007

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

April 21, 2007

Touchdown

6:20 PM CDT (23:20 UTC)

Lifted

6:24 PM CDT (23:24 UTC)

On the ground

4 minutes

Path length

2.0 miles (3.2 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

County

Lamb County

Touchdown point

33.920, -102.424

Lift-off point

33.952, -102.413

Record number

0704211720-01

An outbreak of severe weather impacted much of the central U.S. from Minnesota to Texas during the late afternoon and evening hours of the 21st. The west Texas South Plains and the extreme southern Texas Panhandle were affected by a series of significant tornadoes. At least five tornadoes were spawned by a single cyclic supercell thunderstorm that resulted in more than $3.5 million in damages.|The most severely impacted communities included Olton (Lamb County) and Tulia (Swisher County). Both of these west Texas towns were impacted by EF-2 tornadoes that destroyed property and injured four people, and more than 14,000 customers were without electrical power throughout the night.|The tornado outbreak was caused by a potent storm system that progressed east over the Four Corners region of the western U.S. on the 21st. A potent upper level jet stream spread over the Southern Plains of the U.S., and helped to create a favorable environment for supercell thunderstorms and tornadoes along a dryline that was stretched across west Texas.

A weak tornado developed over open fields in southwestern Lamb County just west of Littlefield. The tornado remained south of U.S. Highway 84 and was photographed by at least two storm chasers. The tornado appeared as a slowly rotating dust whirl with no evidence of a visible condensation funnel. No reports of damage were received. This was the first in a family of five tornadoes that were observed in association with this cyclic supercell storm.

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 tornado watch, issued at 21:03 UTC and running to 02:21 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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:57 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 Lubbock radar (KLBB), 64 km away, was scanning. The volume nearest the touchdown began at 23:20 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 TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

27 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.