EF1 tornado, Melvin to Nanafalia, Alabama, April 15, 2011

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 15, 2011

Touchdown

11:48 AM CDT (16:48 UTC)

Lifted

12:21 PM CDT (17:21 UTC)

On the ground

33 minutes

Path length

16.7 miles (26.9 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$40,000

Counties

Choctaw and Marengo counties

Touchdown point

32.030, -88.246

Lift-off point

32.120, -87.982

Record number

1104151048-01

76 damage points were recorded along this path by NWS BMX and NWS MOB, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 140 mph.

• Dozens of hardwoods and softwoods snapped and uprooted.
• Part of metal roof blown off mobile home.
• Dozens of trees snapped or uprooted.
• Mobile home completely destroyed. One fatalitly occured.

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

Numerous supercell thunderstorms developed in the late morning through the evening hours across Mississippi and Alabama. A series of long track tornadic supercell thunderstorms moved out of southeast Mississippi in the late morning, and crossed southwest Alabama in the late morning through the afternoon and evening hours. In southwest Alabama, the tornadoes missed the larger populated towns and communities, but did produce significant damage to numerous homes in rural areas. Several injuries were reported with 3 fatalities in Deer Park, Alabama (Washington County) from an EF-3 tornado during the early evening hours. Widespread damage to timber along several 200 to 600 yard-wide tornado paths resulted in significant losses to the timber industry. The Alabama Forestry Commission estimated timber losses in southwest Alabama to be near 7.3 million dollars.

A potent storm system, which wreaked havoc across the eastern half of the United States on April 14-16, produced a significant and historic tornado outbreak across Central Alabama on April 15. Forty tornadoes, 30 of which touched down in Central Alabama, occurred in the state. At the time, this set a new record for number of tornadoes within the state from one event. This record was broken on April 27, 2011. ||A surface low developed across the Central Plains on Thursday, April 14, and strengthened as it moved into the mid-Mississippi River Valley. In response, surface dew points in the middle to upper 60s surged northward into Central Alabama and deep vertical wind shear increased, providing support for tornadic supercell development. A weakening line of thunderstorms moved into northwest Central Alabama early Friday morning. The southern end of this line intensified by mid day as it encountered a more unstable airmass. South of the line, supercells formed in Mississippi and tracked eastward into west Central Alabama. The entire system pushed east across the area over the course of about twelve hours, exiting east Central Alabama in the early morning hours on Saturday, April 16. In addition to the thirty tornadoes, the storm system produced widespread straight line wind damage and numerous large hail reports.

Brief tornado touchdown at the Hunt Oil Refinery near Melvin. Minor damage to outbuildings and some trees were snapped.

Tornado touched down near Hurricane Road taking the roof off of one mobile home and damaging one other. The tornado continued northeast across Melvin road and was tracked by a local newspaper reporter on the scene farther to the northeast.

A large tree was blown over onto a manufactured home with 3 persons trapped inside for several minutes approximately 4 miles north-northwest of the community of Ararat. Several trees were blown over or snapped along the tornado path.

A tornado initially touched down in Choctaw County (see Mobile Storm Data), and moved northeastward into Marengo County, where several trees were snapped or uprooted. The damage path for this tornado is based on eyewitness accounts. The area was impacted by stronger tornado in the afternoon hours that took roughly the same path. The tornado lifted just northeast of Nanafalia.

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

7 minutes of warning. NWS MOB issued a tornado warning for this county at 16:41 UTC, 7 minutes before the tornado touched down, in force until 17:45 UTC.

The county was under a tornado watch, issued at 16:22 UTC and running to 00:48 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:17 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.

Meridian/Key Field (MEI), 67 km from the path, in the two hours either side.

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

The Mobile radar (KMOB), 156 km away, was scanning. The volume nearest the touchdown began at 16:47 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 2011 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

74 more were confirmed in the United States that day.

All 75 of them

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.