EF0 tornado, Siloam, Alabama, February 7, 2018

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

February 7, 2018

Touchdown

5:11 AM CST (11:11 UTC)

Lifted

5:14 AM CST (11:14 UTC)

On the ground

3 minutes

Path length

2.0 miles (3.2 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

County

Sumter County

Touchdown point

32.428, -88.276

Lift-off point

32.426, -88.242

Record number

1802070511-01

15 damage points were recorded along this path by NWS BMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

• unsure if tornados. damage confined to SSW portion of the roof.
• tree facing 30 deg. top off of pine
• both trees uprooted facing 30 deg close and 50 deg far
• portion of northeast side ripped off

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

A line of thunderstorms moved across Central Alabama during the early morning hours of Wednesday, February 7, 2018. Supercells embedded within the line were responsible for producing large hail, damaging winds, and several tornadoes. Severe weather was not anticipated as most model guidance indicated insufficient instability and wind shear for the development of supercells, tornadoes and other severe convective hazards. Even so, a marginal risk was highlighted for the western and southern portions of Central Alabama. The storms exhibited organization and frequent lightning, indicators that instability was likely higher than expected. The radar signatures were marginal at best and therefore, only a few Severe Thunderstorm Warnings were issued during the event.

The National Weather Service surveyed damage near Siloam in southern Sumter County and determined the damage was consistent with an EF0 tornado, with maximum sustained winds near 80 mph. The tornado started on the east side of a private lake south of Buck Creek where it uprooted two trees, one causing minor damage to a lake house roof. The tornado continued east into a forested area near Buck Creek where it uprooted several more trees. The tornado continued east toward a convenience store at the intersection of County Road 9 and Highway 17. It caused heavy roof damage to the south side of a house and tore two pieces of sheet metal off of the convenience store. The tornado continued east through a densely forested area and tree damage was found further east along a portion of Walker Road between Highway 17 and U.S. Highway 80. The tornado likely dissipated just to the east of this point.

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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 05:43 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), 162 km away, was scanning. The volume nearest the touchdown began at 11:12 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 2018 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

10 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.