EF4 Lake Martin tornado, Alabama, April 27, 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 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 mphthis tornado

   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

EF4

Date

April 27, 2011

Touchdown

8:12 PM CDT (01:12 UTC)

Lifted

9:09 PM CDT (02:09 UTC)

On the ground

57 minutes

Path length

44.2 miles (71.1 km)

Path width

880 yards (805 m)

Deaths

7

Injuries

30

Property damage

$167 million

Counties

Elmore, Tallapoosa and Chambers counties

Touchdown point

32.617, -86.193

Lift-off point

32.920, -85.523

Record number

1104271912-01

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 EF4. The highest wind the damage implies is 170 mph.

• End Point of Lake Martin EF-4 Tornado.
• Large Oak Trees had large branches snapped off to the stubs and vegetation stripped.
• Pickup truck thrown almost 115 yards away from where it was parked.
• Path width one quarter mile. Some hardwood trees severely damaged with small core left.

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

A powerful storm system crossed the Southeast United States on Wednesday, April 27, 2011, resulting in a large and deadly tornado outbreak. This epic event broke the record for number of tornadoes in a day for the state of Alabama, becoming the most significant tornado outbreak in the state���s history. ||Central Alabama had two rounds of severe weather that day. During the early morning hours, a Quasi-Linear Convective System quickly moved across the northern half of the National Weather Service, Birmingham county warning area. Straight line winds of 90 mph (78kts) or greater and 11 tornadoes lead to widespread damage and power outages. During the afternoon, long-lived supercell thunderstorms produced long-track, strong and violent tornadoes. Destruction and loss of life across many towns and communities was devastating. ||The hardest hit areas included Shottsville and Hackleburg, both in Marion County, where winds of 160 mph and 210 mph respectively, caused unimagineable damage. Cordova, in Walker County, was hit twice; by a tornado along the Quasi-Linear Convective System during the early morning hours and again in the afternoon by a long-track EF4 tornado. A long track tornado moved across the city of Tuscaloosa and the western suburbs of Birmingham, resulting in the complete destruction of whole neighborhoods and numerous injuries and fatalities in those heavily populated areas. The same parent supercell produced another violent tornado in east Central Alabama as it tracked across St. Clair and Calhoun Counties, resulting in additional fatalities and incredible damage to a number of neighborhoods. Another violent EF4 tornado tracked across portions of Elmore and Tallapoosa Counties, including Lake Martin, destroying numerous homes and a large section of a mobile home park. ||Most of the violent tornadoes from this day were captured on video by a number of people, including storm spotters and chasers, as well as numerous television news crews and remotely controlled web-enabled video cameras. This allowed unprecedented coverage and viewing of this historic event in real time from people worldwide.

A tornado touched down in central Elmore County and moved northeast through central Tallapoosa and western Chambers Counties, before it lifted north northwest of Lafayette. The tornado touched down north of Wetumpka, along CR 209 where a few trees were downed and minor home damage were noted. The tornado quickly intensified as it moved northeast through Dexter, where it caused major damage to several homes, outbuildings and farm equipment that was consistent with winds of 130 mph, an EF2. It continued across AL Hwy 9 and damaged several homes. The tornado intensified south of Central to EF3 strength, where it destroyed a mobile home and damaged several single family homes near CR 418. It moved through a mobile home park at the intersection of Middle Road and Auction Barn Road, where it completely destroyed 10 mobile homes and killed 4 people. The tornado continued east to the Mount Hebron Road area. Here, the tornado destroyed several homes, businesses, 2 churches, and an agricultural nursery. The tornado then crossed Lake Martin, just south of the AL Hwy 63 Bridge, doing significant damage to numerous homes around the Windermere area, as its path widened to 0.5 mile. The tornado crossed into Tallapoosa County near Stoney Ridge Rd.

A tornado touched down in central Elmore County, north of Wetumpka, and moved northeast through central Tallapoosa and western Chambers Counties, before it lifted west northwest of Lafayette. The tornado crossed into Tallapoosa County near Stoney Ridge Rd, south of CR 34, and intensified to EF4 strength with winds of 170 mph. Damage was widespread and severe with several well built multi-story homes destroyed with no walls remaining on floors above basement level. The tornado continued at this strength but became narrower to nearly 400 yards wide as it crossed AL Hwy 49 south of Dadeville where it destroyed 2 homes and rolled a pick-up truck 120 yards. The tornado continued northeast and weakened to EF3 strength with winds of 155 mph. It crossed U.S. Hwy 280 just east of Dadeville where it produced significant damage to several homes and businesses, and caused one fatality. The tornado crossed into Chambers County west of Lafayette, south of CR 48.

A tornado touched down in central Elmore County, north of Wetumpka, and moved northeast through central Tallapoosa County and crossed into western Chambers County, west of Sikes, south of CR 48. The tornado tracked northeastward with winds of 150 mph, an EF3. One home was destroyed along CR 54. It gradually weakened and lifted northeast of the intersection of CR 51 and CR 66, 7 miles west northwest of Lafayette.

The deaths

7 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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

39 minutes of warning. NWS BMX issued a tornado warning for this county at 00:33 UTC, 39 minutes before the tornado touched down, in force until 01:30 UTC.

The county was under a tornado watch, issued at 22:52 UTC and running to 06:01 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 High Risk, with a 0.30 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:50 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.

Alexander City (ALX), 19 km from the path, in the two hours either side.

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

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

209 more were confirmed in the United States that day.

All 210 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.