EF1 tornado, Grove Oak to Ider, 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 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, 2011

Touchdown

6:58 AM CDT (11:58 UTC)

Lifted

7:36 AM CDT (12:36 UTC)

On the ground

38 minutes

Path length

27.9 miles (44.8 km)

Path width

300 yards (274 m)

Deaths

1

Injuries

0

Counties

DeKalb and Jackson counties

Touchdown point

34.574, -85.968

Lift-off point

34.838, -85.598

Record number

1104270558-01

35 damage points were recorded along this path by NWS FFC and NWS HUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF5. The highest wind the damage implies is 185 mph.

• Start Point of Lakeview to Rainsville to Cartersville EF-5 Tornado.
• End point in Alabama of Lakeview to Rainsville to Cartersville EF-5 Tornado.
• Start point of Section-Flat Rock EF-4 Tornado.
• End point of Section-Flat Rock, GA EF-4 Tornado in Alabama.

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

A powerful storm system roared across the Southeast United States on Wednesday, April 27, 2011. In the wake of this system, hundreds of people were left injured and/or homeless, along with approximately 100 people who lost their lives in the northern Alabama area alone. Some of the devastation was literally unimaginable with countless homes, neighborhoods and even portions of cities or towns either partially or completely destroyed. This storm system would be responsible for one of the largest and deadliest tornado outbreaks to ever impact much of the southeastern region.| |The powerful storm system that affected the National Weather Service, Huntsville service area would actually occur in three separate waves of severe weather that day. The first occurred during the early morning hours of April 27, 2011 roughly between the hours of 2 AM and 8 AM CDT, while the second occurred during the late-morning to early afternoon period. The third and most devastating wave occurred during the afternoon hours on Wednesday, with some of the most violent and destructive tornadoes to affect the central Tennessee Valley area in recent decades.| |The worst areas impacted by these storms included the towns of Phil Campbell and Oak Grove in eastern Franklin County Alabama, Mt. Hope in western Lawrence County and the Tanner Community in eastern Limestone County. Along a line connecting these areas tracked an EF5 tornado with peak winds around 210 mph, the strongest and most violent on the Enhanced Fujita Scale. ||Other areas impacted by the storms include the city of Cullman, where extensive damage occurred to buildings in the downtown area, and to the town of Fairview, both of which are located in Cullman County. Downstream, further significant damage occurred to the Ruth and Oak Grove communities in Marshall County. In addition, the communities of Rainsville and Sylvania along with the towns of Henagar and Ider in DeKalb County were severely impacted. Fatalities in DeKalb County alone numbered at least 33 people. Furthermore, the towns of Flat Rock, Higdon and Pisgah in Jackson County sustained incredible damage. The tornadoes that affected these areas were rated as an EF4 with maximum winds near 190 mph.||In most of these areas alone, numerous people lost their lives. These represent just several of the communities and towns impacted by the events of April 27, 2011. While the majority of the analysis and survey work conducted by the National Weather Service, Huntsville and its partners have been completed, there will undoubtedly be countless research studies conducted by both academia and operational personnel in order to further evaluate and understand the complex processes associated with this near unprecedented severe weather outbreak.

The tornado continued its path briefly northeast into DeKalb County, mainly snapping large tree limbs off of trees and uprooting a few trees. The tornado then dissipated between Grove Oak and Bucks Pocket State Park near CR 19 and CR 544.

A tornado of EF-1 intensity produced wind speeds of up to 110 mph. The tornado touched down just south of Section, crossing State Highway 35, then traveling nearly parallel to State Highway 71, through Dutton, into southern portions of of Pisgah before crossing into far northern DeKalb County. The tornado uprooted and snapped numerous trees along its path, knocking out power in many locations. One fatality occurred in the Pisgah area associated with this tornado.||The tornado took a very similar track to a violent tornado of EF-4 intensity later during the afternoon of the 27th. This made it very difficult to distinguish damage between the two tornadoes. Several eyewitnesses remarked about the morning tornado location and damages.

The tornado touched down very briefly in the Henagar area and tracked northward. |Numerous large trees, some old oak trees, were snapped. Other large trees were uprooted as well along this portion of the track in DeKalb County.

The tornado continued moving north northeast from DeKalb County into Jackson County destroying at least 3 barns. The tornado produced EF-2 intensity winds as it struck a well constructed home south of Rosalie, collapsing the west end of the home completely. A shed was destroyed on this property as well. Additional trees were snapped or uprooted in Rosalie along highway 71. The tornado then turned more northeast along highway 71 snapping or uprooting several more large trees. The tornado lifted near the junction of highway 71 and CR 345.

A tornado producing damage of EF-1 intensity with peak winds of up to 100 mph touched down near Mentone. The tornado first touched down west of County Road 89 north of downtown Mentone. The tornado moved along a ridge line uprooting many softwood and hardwood trees and snapping them sporadically. The tornado eventually straddled the road further north partially removing a roof to a residence and snapping numerous trees in this area. The tornado lifted about a mile shy of the Georgia state line.

A tornado of EF-1 intensity producing wind speeds of up to 110 mph tracked out of Jackson County and took a short path into DeKalb County. Details are limited with this tornado path as later this same day, a violent tornado of EF-4 intensity struck the same area in a similar path making it very difficult to distinguish damage between the two tornadoes.

The deaths

1 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.

21 minutes of warning. NWS HUN issued a tornado warning for this county at 11:37 UTC, 21 minutes before the tornado touched down, in force until 12:00 UTC.

The county was under a tornado watch, issued at 07:36 UTC and running to 13:00 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 06:10 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 Northeast Alabama radar (KHTX), 37 km away, was scanning. The volume nearest the touchdown began at 11:59 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

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.