EF0 tornado, Longhorn to Kirby, Texas, March 19, 2012

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

March 19, 2012

Touchdown

12:55 AM CDT (05:55 UTC)

Lifted

12:57 AM CDT (05:57 UTC)

On the ground

2 minutes

Path length

0.8 miles (1.2 km)

Path width

10 yards (9 m)

Deaths

0

Injuries

0

County

Bexar County

Touchdown point

29.535, -98.412

Lift-off point

29.527, -98.405

Record number

1203192355-01

A deep upper level trough of low pressure and strong cold front moved into an area of deep boundary layer moisture. The system initially produced supercell thunderstorms which produced several tornadoes and large hail. There storms then transitioned into a quasi-linear convective system that produced heavy rainfall and flooding.

Minor damage near the San Antonio post office on Perrin Beitel Rd was caused by a small tornado that formed along the leading edge of a large cluster of storms pushing east in the early morning hours of March 20 (CDT). This cluster of storms interacted with an outflow boundary causing a few brief tornadoes. In addition to the damage at the post office, one home sustained major damage and 10 others were left with minor damage. Seventy-three other homes were affected by the tornado with other property damage; either debris on the property or damage to fences and plants.

A second small tornado formed along the leading edge of a large cluster of storms pushing east through northeastern San Antonio in the early morning hours of March 20 (CDT). One home on Castle Hunt Dr. received minor damage and 25 other homes on Castle Hunt Dr. and Castle Run were affected either with debris on the property or damage to fences or plants.

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 05:53 UTC and running to 10:13 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 Moderate Risk, with a 0.10 chance of a tornado within 25 miles. 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.

San Antonio (SAT), 6 km from the path, in the two hours either side.

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

The Austin/San Antonio radar (KEWX), 41 km away, was scanning. The volume nearest the touchdown began at 05:55 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 2012 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

9 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.