EF1 tornado, Tarzan to Ackerly, Texas, April 16, 2009

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

April 16, 2009

Touchdown

9:55 PM CDT (02:55 UTC)

Lifted

10:12 PM CDT (03:12 UTC)

On the ground

17 minutes

Path length

7.4 miles (11.9 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$7,000

County

Martin County

Touchdown point

32.324, -101.778

Lift-off point

32.391, -101.680

Record number

0904162055-01

A mid to upper level closed low was located over southwest Utah the day of the event. Near the surface, a quasi dryline was located from a line near the mountains of west Texas to the eastern NM/TX border. Dewpoints in the low to mid 50 F range resulted in moderate surface based instability east of the dryline during the early evening hours. The upper dynamics combined with the surface convergence along the dryline led to the development of severe weather as the deep layer shear increased with the approach of the aforementioned feature. There was also a brief window for tornadic storms as low level profiles became increasingly backed east of the dryline as height falls increased ahead of the upper trough just west of the region. A tornado watch was issued from 1642-2400 local.

This tornado first did damage to 7 power poles about 4.5 miles southwest of Tarzan; this was confirmed by contacting the utility company in the area the following day. The estimated time of damage according to radar at this location was around 2020 CST. At 2032 CST, the tornado then tracked east northeastward and impacted a COOP observer's farm about 3 miles southeast of Tarzan, TX damaging multiple pieces of farm equipment, storage tanks and removing 3 roofs from multiple structures. It then continued on its same path snapping 3 power poles about a mile west of Lenorah, TX. The estimated time of damage according to radar was sometime around 2036 CST. This was the last known location of the tornado, although another tornado redeveloped with the same supercell about 20 minutes later. Please see the attached images.

A damage survey conducted across west central Martin County concluded that there was a tornado that tracked northeastward for approximately 7 miles, doing minor damage on the way. The first signs of damage were observed at a residence where a 10'X6'X6' wooden storage structure was blown to the east northeast about 60 feet. According to radar imagery, this was near 2055 PM CST. In addition, minor roof damage was done to the home by west winds and the family's trampoline was wrapped around a nearby tree in the backyard. The tornado then continued northeastward where it passed just to the north of two power poles that were snapped at the ground by damaging west winds sometime around 2112 PM CST. The closest estimate of the path taken by the tornado has been attached.

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

28 minutes of warning. NWS MAF issued a tornado warning for this county at 02:27 UTC, 28 minutes before the tornado touched down, in force until 03:30 UTC.

The county was under a tornado watch, issued at 21:42 UTC and running to 05:00 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 00:55 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.

Big_spring (BPG), 25 km from the path, in the two hours either side.

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

The Midland/Odessa radar (KMAF), 63 km away, was scanning. The volume nearest the touchdown began at 02:55 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 2009 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

15 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.