EF0 tornado, Hells Xrds, Alabama, April 27, 2017

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

April 27, 2017

Touchdown

4:18 PM CDT (21:18 UTC)

Lifted

4:22 PM CDT (21:22 UTC)

On the ground

4 minutes

Path length

1.2 miles (1.9 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

County

Barbour County

Touchdown point

31.921, -85.510

Lift-off point

31.925, -85.491

Record number

1704271518-01

30 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.

• Large tree uprooted to the west, large pine tree cut through middle of home. Complete loss.
• Carport collapse due to falling pine tree. metal structure and supports.
• 5pm, witness homeowner says tornado formed over Court house and moved near mobile home and damaged tree at this home, no damage to home.
• Tree in poor health fell onto roof, created 6 holes in the roof.

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

A pre-frontal trough moved into Central Alabama on Tuesday night, April 26th. This boundary slowly pushed southward and was accompanied by some showers and thunderstorms. The east to west boundary drifted into south central Alabama on the morning of April 27th. The combination of shear, lift along the boundary, increased low level moisture and instability produced by insolation was just enough to spin up a few weak tornadoes.

NWS Meteorologists surveyed damage in central Barbour County and determined the damage was consistent with an EF0 tornado, with maximum sustained winds of 65 mph. The tornado touched down in a wooded area between Williams Spur and County Road 51, just northwest of the city of Clayton. The tornado caused sporadic tree damage, mostly branches. Some of the areas were completely inaccessible. Two hunters filmed the tornado as it went by.

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.

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. The outlook in force was issued at 20:00 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 Ft Rucker radar (KEOX), 52 km away, was scanning. The volume nearest the touchdown began at 21:16 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 2017 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

5 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.