F1 tornado, Albertville, Alabama, September 22, 2006

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

September 22, 2006

Touchdown

6:06 PM CDT (23:06 UTC)

Path length

3.2 miles (5.1 km)

Path width

500 yards (457 m)

Deaths

0

Injuries

0

Property damage

$90,000

County

Marshall County

Touchdown point

34.230, -86.230

Lift-off point

34.270, -86.220

Record number

920

A very moist and unstable environment and strong directional and speed wind shear resulted in an environment favorable for supercell thunderstorms as a warm front tracked northeast through the area. Several supercell thunderstorms erupted during the early afternoon across northwest and north central Alabama, with storms redeveloping through early evening across northeast Alabama. Many of these storms exhibited storm tops that climbed to over 55,000 feet. Nearly all of the storms exhibited a mesocyclone of weak to moderate strength, posing a tornado threat. Numerous photographs were taken by television viewers or newspapers of these storms. The photos indicated recognizable storm structures usually documented by supercell storms including mesocyclones and wall clouds. However, only three tornadoes were confirmed in the Huntsville National Weather Service service area by storm survey, spotter report or photographs.

The tornado initially touched down in the southwest side of Albertville between Whitesville Road and South Broad Street. At this stage, the tornado was 40 yards wide producing F0 intensity winds up to 60 mph for along a one quarter mile path. Then the tornado increased to F1 intensity with winds up to 100 mph along a path width of 500 yards. Several trees were snapped and uprooted in its path. Several homes sustained minor roof, awning, and gutter damage. The tornado continued its path north-northeast into western Albertville before dissipating.

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

1 minute of warning. NWS HUN issued a tornado warning for this county at 23:05 UTC, 1 minute before the tornado touched down, in force until 23:45 UTC.

The county was under a tornado watch, issued at 19:39 UTC and running to 00:00 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 General Thunderstorms Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:56 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.

Albertville (BFZ), 3 km from the path, in the two hours either side.

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

The Northeast Alabama radar (KHTX), 77 km away, was scanning. The volume nearest the touchdown began at 23:07 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 2006 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

32 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.