EF1 tornado, Quito to Cooley, 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

5:50 AM CDT (10:50 UTC)

Lifted

5:54 AM CDT (10:54 UTC)

On the ground

4 minutes

Path length

3.4 miles (5.5 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$3.7 million

Counties

Shelby and Jefferson counties

Touchdown point

33.378, -86.751

Lift-off point

33.425, -86.736

Record number

1104270450-01

44 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.

• .Numerous large trees uprooted and snapped
• Lots of trees snapped as tornado crossed US-280.
• .Apparent beginning point of Cahaba Heights tornado. A few twigs broken, and a couple large trees uprooted.
• .Nearly all trees in this area were snapped off or uprooted. Many of them landed on houses, causing extensive damage.

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 developed along a Quasi-Linear Convective System. It touched down in far northern Shelby County, less than one mile west of the intersection of Valleydale Road and Caldwell Mill Road, and tracked northeastward into southern Jefferson County. The tornado produced damage consistent with an EF1 rating and winds of 100 mph. Numerous trees were knocked down, causing damage to homes, apartment buildings, vehicles and power lines. The tornado crossed into Jefferson County just east of the intersection of Caldwell Mill Rd and Pahokee Trace.

A tornado developed along a Quasi-Linear Convective System, touching down in far northern Shelby County, northeast of Hoover. The tornado tracked northeastward crossing into southern Jefferson County, just east of the intersection of Caldwell Mill Rd and Pahokee Trace. The tornado weakened to an EF0 rating and produced tree damage until it lifted near the intersection of Acton Place and Caldwell Mill Rd.

A tornado developed along a Quasi-Linear Convective System. It touched down in south central Jefferson County where it affected the Cahaba Heights and Liberty Park communities of the Birmingham Metro area. The tornado touched down near Gresham Elementary School. It knocked down several trees along Country Ridge Pl. The tornado moved northeast and crossed US Hwy 280, near Dolly Ridge Rd where it knocked down numerous trees and damaging buildings along the highway. The tornado strengthened as it moved into Cahaba Heights where it produced damage consistent with an EF2 rating and winds of 120 mph. The most significant area of damage occurred between US Hwy 280 and Cahaba Heights Rd, near Cahaba Heights Elementary School, where numerous homes sustained significant damage from fallen trees. The tornado weakened to an EF1 rating with winds of 100 mph as it continued northeast, but still knocked down trees which resulted in damage to homes and businesses. The tornado crossed Interstate 459 south of Liberty Park knocking down dozens of trees, and continued northeast causing minor tree damage. The tornado lifted near Grants Mill Rd, 2 miles south of Interstate 459. A person was killed (indirect) during clean-up efforts.

The deaths

0 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 BMX issued a tornado warning for this county at 10:29 UTC, 21 minutes before the tornado touched down, in force until 11:00 UTC.

The county was under a tornado watch, issued at 07:26 UTC and running to 12:14 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 Birmingham radar (KBMX), 26 km away, was scanning. The volume nearest the touchdown began at 10:49 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.