EF1 tornado, Harleton, Texas, January 20, 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

January 20, 2010

Touchdown

7:44 PM CST (01:44 UTC)

Lifted

7:46 PM CST (01:46 UTC)

On the ground

2 minutes

Path length

0.3 miles (0.5 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$300,000

County

Harrison County

Touchdown point

32.673, -94.578

Lift-off point

32.675, -94.573

Record number

1001201944-01

A very warm and unstable air mass developed across the region on January 20th. This air mass was accompanied by unusually high dewpoint values for late January with ambient temperatures approaching the 70 degree mark. A very strong and vigorous storm system moved out of the Great Basin and into the Southern Plains and Lower Mississippi Valley during the late afternoon and evening hours of January 20th. Wind shear throughout the atmosphere was very strong and supportive of strong to severe thunderstorms. Low level wind shear was significant enough such that super cell thunderstorms developed across the region, producing tornadoes, large hail and damaging wind gusts.

A NWS storm survey team determined that the damage near Harleton, Texas was consistent with a short lived tornado. Two brick buildings sustained minor roof and structural damage, and a grocery store sustained some roof and awning damage. Several trees were also uprooted.

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 21:53 UTC and running to 04:00 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 0.10 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 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 Shreveport radar (KSHV), 73 km away, was scanning. The volume nearest the touchdown began at 01:42 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 TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

13 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.