EF1 tornado, (Ali)Alice Intl Arpt to Calallen, Texas, January 9, 2011

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 9, 2011

Touchdown

3:25 AM CST (09:25 UTC)

Lifted

3:51 AM CST (09:51 UTC)

On the ground

26 minutes

Path length

23.3 miles (37.5 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$5.0 million

Counties

Jim Wells and Nueces counties

Touchdown point

27.711, -97.966

Lift-off point

27.854, -97.623

Record number

1101090325-01

A cold front moved through South Texas on Saturday morning, January 8, 2011 and was situated over Deep South Texas Saturday afternoon, with temperatures generally in the 50s area-wide. However as the storm system approached, a surface low pressure area formed along the frontal boundary, which helped to draw warm and humid conditions northward into the Coastal Bend. ||As the upper level storm system moved through the region, very strong wind shear developed and combined with an unstable atmosphere to produce a line of severe thunderstorms. A tornadic thunderstorm developed near the proximity of the surface low and retreating warm front, which persisted for over 20 miles travelling from just southeast of Alice to near Calallen. Damaging straight line winds affected most of the Coastal Bend and extended well into the Gulf of Mexico east of Rockport. Widespread wind damage was observed across the Coastal Bend as the storms moved quickly through the region. Approximately 30,000 customers lost power as a result of the storms. This marks the first time a tornado has been recorded in South Texas in the month of January, dating back to 1950. Property damage for the tornado and straight-line winds for the Coastal Bend was estimated to be around 10 million dollars. ||From Calallen through Portland and Rockport, doppler radar indicated a broad, yet strong rotation between 4 and 430 AM CST. A NWS storm survey concluded straight-line winds between 70 and 90 mph occurred along this path. A path length of damage of nearly 65 miles was observed from the starting point of the tornado in Jim Wells County to the end of the straight-line wind damage in Rockport. ||Further north, doppler radar indicated another bowing segment in the line across Victoria and Calhoun Counties between 400 and 500 AM CST. The Seadrift TCOON site recorded a wind gust of 70 mph. A NWS storm survey team concluded straight line wind speeds of around 70 mph occurred from rural southern Victoria County to Seadrift in southwestern Calhoun County.

A NWS storm survey concluded a tornado started roughly 4 miles southeast of the Alice International Airport and continued northeast into Nueces County. The tornado damaged trees and blew down 2 power poles just south of FM 665.

A National Weather Service (NWS) storm survey team determined a tornado, that touched down 4 miles southeast of Alice International Airport in Jim Wells county continued northeast for 21.5 miles. It travelled through the northwest side of Robstown and ended near Five Points in Calallen. The tornado was strongest from the west-southwest side of Robstown to its end point near Calallen, where wind speeds of up to 100 mph and a width of 200 yards were estimated. ||Damage to high voltage power lines, poles, large trees, and signs were observed along the path length. In addition, two large sheds, a barn and a tractor were destroyed southwest of Robstown. On the northwest side of Robstown, numerous trees were snapped and several homes had damage to shingles and wooden roofing. Debris in the form of tin, wood, and sports equipment were strewn across Robstown High School. A large section of the roof of the Robstown High School gymnasium was torn off and a two fifteen-ton air conditioning units, weighing around 1 ton each, were blown off the auditorium. Damage occurred to hundreds of cars at two dealerships south of Calallen.||This was the first tornado on record in South Texas during the month of January. Total property damage was estimated to be around 5 million dollars with the tornado.

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.

The county was under a severe thunderstorm watch, issued at 08:11 UTC and running to 10:11 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 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.

Robstown (RBO), 10 km from the path, in the two hours either side.

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

The Corpus Christi radar (KCRP), 28 km away, was scanning. The volume nearest the touchdown began at 09:24 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 2011 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

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.