F1 tornado, Wilsonville to Childersburg, Alabama, May 7, 2003

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 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

F1

Date

May 7, 2003

Touchdown

2:45 PM CDT (19:45 UTC)

Path length

1.3 miles (2.1 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$170,000

Counties

Shelby and Talladega counties

Touchdown point

33.200, -86.470

Lift-off point

33.180, -86.450

Record number

1116

A developing supercell storm gained strength rapidly as it developed over southern Shelby County moving eastward producing a tornado just south-southeast of Wilsonville. The tornado downed trees and damaged several structures in a residential area on the west side of the Coosa River in Shelby County, crossed the river (boundary between Shelby and Talladega counties), and downed numerous trees in a rural area on the east side of the river. This was the first of several tornadoes from this one thunderstorm.Beg: 33 12.109/86 28.272 End: 33 12.265/86 26.895

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

32 minutes of warning. NWS BMX issued a tornado warning for this county at 19:13 UTC, 32 minutes before the tornado touched down, in force until 20:15 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 16:36 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.

Alabaster (EET), 30 km from the path, in the two hours either side.

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

The Birmingham radar (KBMX), 29 km away, was scanning. The volume nearest the touchdown began at 19:46 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.

The live radar over the trackEvery 2003 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

28 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.