EF1 Tornado — Cherokee, Georgia

2011-09-05 · near Woodstock, Cherokee, Georgia

Event narrative

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].

Wider weather episode

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.

View location on OpenStreetMap → (34.0829, -84.5627)

Source: NOAA Storm Events Database, event_id 346394. Narrative written by the NWS forecast office that issued the report.