EF1 tornado, Woodstock to Marblehill, Georgia, September 5, 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

September 5, 2011

Touchdown

3:11 PM EDT (19:11 UTC)

Lifted

3:56 PM EDT (19:56 UTC)

On the ground

45 minutes

Path length

28.4 miles (45.7 km)

Path width

440 yards (402 m)

Deaths

0

Injuries

1

Property damage

$20 million

Counties

Cherokee and Pickens counties

Touchdown point

34.083, -84.563

Lift-off point

34.450, -84.350

Record number

1109051311-01

3 damage points were recorded along this path by NWS FFC, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

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

Tropical Storm Lee formed from a persistent low pressure area off the upper Texas and Louisiana coasts on the south side of a mammoth subtropical ridge centered across the eastern Ohio valley. This occurred during the late few days of August. The system slowly intensified under weak steering currents and moved onshore the Louisiana coast on the 3rd. Tropical Storm Lee was extremely slow moving at this point and consequently dumped excessive rainfall across southeast Louisiana. A sharp upper trough began to take shape in the central U.S. on September 4th as upper energy dug southeast from Canada. As this occurred, the remnants of Lee began to accelerate northeastward in association with the advancing upper trough. The remnants of Lee traveled very quickly along the advancing front, racing across Georgia on the 5th. Rain bands began to affect the area late on the 4th, but most of these were light to moderate. On the 5th, persistent heavy rain impacted northwest Georgia and resulted in minor flooding. Despite widespread rainfall of four to five inches across northwest Georgia with localized six to eight inches, the ongoing drought across the state resulted in minimal impacts of the heavy rain on the area, The bigger problems came during the afternoon of the 5th when an area of strong shear, associated with the remnants of Lee, tracked from southwest to northeast across the area. This combined with an unstable atmosphere as breaks in the clouds allowed temperatures to warm into the lower 80s. Numerous strong thunderstorm cells developed quickly and tracked first from the Columbus area and west central Georgia into northeast Georgia. Strong mesocyclones were indicated in many of these cells and prompted dozens of tornado warnings. However, only one thunderstorm cell actually netted a tornado, which caused considerable damage in Cherokee county, just northwest of Atlanta.||As the outer remnant feeder bands moved away from the area during the mid-evening, the remnant core of Tropical Storm Lee passed by just to the west across northwest Alabama. A two to three hour window of strong winds gusting to 35 to 40 mph were observed in several northwest Georgia counties as this occurred causing damage to dozens of trees and a number of power lines during this time frame.

A damage survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia and the Cherokee County Emergency Manager confirmed that an EF1 tornado, spawned by strong shear associated with the remnants of Tropical Storm Lee, touched down in southern Cherokee county, just south of the Dixie Speedway, or just west of Woodstock, then tracked north-northeast across eastern Cherokee county before moving into southeastern Pickens county near the city of Nelson. The tornado, with a semi-continuous path nearly 24 miles long across Cherokee county, had a maximum path width of 1/4 mile and maximum wind gusts of 90 mph. The tornado caused extensive damage to homes and business across eastern Cherokee county. The Brookshire and Town Lake Hills South subdivisions sustained much of the structural damage within the county. The Dixie Speedway, just west of Woodstock, suffered extensive damage as well. A number of recreational vehicles and boats were parked at the facility in anticipation of an event. Dozens of these were overturned and destroyed by the tornado. Over 600 single-family homes sustained some form of structural damage, with seven of these homes completely destroyed. One injury was confirmed at one of the heavily damaged homes. A total of 148 homes sustained major damage and 269 sustained minor damage. In addition, six apartment units sustained damage, with three of these classified as having major damage. Twenty commercial businesses were affected by the tornado, three of which were destroyed. Sixteen of these businesses suffered major damage. Finally, three churches sustained damage, two of which suffered major damage. In addition to the structural damage, hundreds of trees were damaged or destroyed by the tornado, many of which subsequently caused damage to adjacent structures and dozens of vehicles.||[09/05/11: Tornado #1, County #1-2, EF1, Cherokee-Pickens, 2011:025].

The Pickens County Emergency Management Director confirmed that the EF1 tornado, which originally touched down in far southern Cherokee county just west of Woodstock and continued on a north-northeastward track across eastern Cherokee county, entered Pickens county at the city of Nelson. Damage in Pickens county remained consistent with an EF1 rating. From here, the tornado continued north-northeast to just past Marble Hill before finally lifting. Within Pickens county the tornado had a path length of approximately five miles with a maximum path width of 220 yards or 1/8 mile. Eleven homes were damaged along the path of the tornado within Pickens county. One of these homes was completely removed from its foundation and destroyed. Four other homes suffered major damage, three with moderate damage, and the remaining three minor damage. The majority of this damage was in the Marble Hill community. In addition, three structures at the Emory Marble Plant in Marble Hill suffered major damage. Dozens of medium to large-sized trees, including several large oak trees, were downed along the path of the tornado. Several roads were completely blocked as a result, including a portion of Georgia Highway 53 between Tate and Marble Hill.||[09/05/11: Tornado #1, County #2-2, EF1, Cherokee-Pickens, 2011:025].

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

23 minutes of warning. NWS FFC issued a tornado warning for this county at 18:48 UTC, 23 minutes before the tornado touched down, in force until 19:30 UTC.

The county was under a tornado watch, issued at 16:10 UTC and running to 19:42 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. The outlook in force was issued at 16:30 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.

Canton/Cherokee_cnty_arpt (47A), 6 km from the path, in the two hours either side.

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

The Atlanta radar (KFFC), 101 km away, was scanning. The volume nearest the touchdown began at 19:10 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 GeorgiaEvery tornado in Georgia since 1950Warnings in force in Georgia nowThe forecast where you are

8 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.