EF1 tornado, Corcoran to Cataloe, Alabama, April 27, 2017

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

April 27, 2017

Touchdown

11:25 AM CDT (16:25 UTC)

Lifted

11:35 AM CDT (16:35 UTC)

On the ground

10 minutes

Path length

4.9 miles (7.9 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

County

Pike County

Touchdown point

31.835, -85.931

Lift-off point

31.868, -85.857

Record number

1704271025-01

39 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.

• many trees snapped or uprooted on south side of road
• poorly built shed destroyed, tin strewn well downstream
• uprooted tree on vacant house
• pole barn damaged off road

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 Pike County just northeast of the city of Troy and determined the damage was consistent with an EF1 tornado, with maximum sustained winds near 95 mph. The tornado formed just south of the intersection of Highway 29 and Radio Station Road. The tornado snapped and uprooted dozens of trees as it moved through residential areas south of Highway 29, damaging or destroying several outbuildings and causing minor shingle and overhang damage to homes. In addition, a mobile home was flipped over onto its roof just before Thomas Road, but did not appear to be well-anchored. The tornado crossed Highway 29 just west of the Dunn community. As the tornado crossed County Road 7757, one large hardwood tree was snapped and another was uprooted, falling on a home. The tornado paralleled County Road 7761, continuing to snap and uproot dozens of additional softwood and hardwood trees. A poorly built shed was completely destroyed near the intersection with CR 7759 with tin lofted well downstream. Tree damage began to diminish farther northeast and the tornado dissipated before reaching Highway 223.

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

4 minutes of warning. NWS BMX issued a tornado warning for this county at 16:21 UTC, 4 minutes before the tornado touched down, in force until 16:45 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 Marginal Risk. The outlook in force was issued at 12:55 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.

Troy Municipal (TOI), 11 km from the path, in the two hours either side.

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

The Ft Rucker radar (KEOX), 60 km away, was scanning. The volume nearest the touchdown began at 16:23 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.