EF1 tornado, Thomas Jct to North Birmingham, Alabama, December 10, 2012

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

December 10, 2012

Touchdown

4:43 AM CST (10:43 UTC)

Lifted

4:45 AM CST (10:45 UTC)

On the ground

2 minutes

Path length

1.1 miles (1.7 km)

Path width

250 yards (229 m)

Deaths

0

Injuries

0

County

Jefferson County

Touchdown point

33.536, -86.844

Lift-off point

33.542, -86.827

Record number

1212100443-01

17 damage points were recorded along this path by NWS BMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 95 mph.

• End point of Birmingham EF-1 Tornado.
• left edge of tornado track
• right edge of path. 5 homes in area with similar damage.
• .Two homes with significant roof damage. One roof was removed and reportedly found on Carraway blvd

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

An upper level disturbance developed west of the Rockies and then ejected eastward. At the surface, a surface low developed over the Central Plains, with a cold front trailing southward. As this system moved eastward, showers and thunderstorms developed ahead of the cold front and moved into a slightly unstable air mass across Central Alabama. While the overall system was weakening as it moved across the area, there was enough instability and wind shear to support an isolated tornado and several severe wind reports.

The tornado touched down just west of 3rd Place West or just to the east of the Birmingham Farmers Market. From there, it moved to the northeast across a light industrial warehouse area, striking a large metal building. Several overhead doors at the loading dock were blown in, which then blew off about 25 percent of the roof. Debris from this structure was found up to a mile away. The tornado continued northeastward through a residential area, causing damage to 29 homes, 2 of which had major damage and one of which lost its roof entirely. A church and two other businesses were damaged near the intersection of Finley Blvd and 16th Street. The tornado lifted near the intersection of 24th Court North and 18th Street North, just west of Interstate 65.

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.

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 05:52 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 Birmingham radar (KBMX), 41 km away, was scanning. The volume nearest the touchdown began at 10:43 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 AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

6 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.