EF1 tornado in Coweta County, Georgia

A damage survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia confirmed that a brief EF1 tornado affected south central Coweta county. While damage was initially determined to be caused by strong straight line winds responsible for isolated tree and power line damage just north of Grantville, a brief EF1 tornado subsequently touched down as the storm progressed further northeast. The tornado touched down approximately two miles southwest of Moreland and tracked on the ground for just slightly over one mile, lifting approximately 1.2 miles southwest of Moreland. The tornado was determined to have a maximum path width of 100 yards with maximum winds of 90 mph. EF1 tornado damage began immediately upon touchdown along Polk Road where dozens of trees were snapped. Tree damage continued to the northeast along Dingler Road. One home on Polk Road sustained substantial damage to its roof. Several trees were also uprooted or snapped on this property as well.

[12/22/11: Tornado #4, County #1-1, EF1, Coweta, 2011:030].

A deep trough, quite characteristic of the early winter season of 2011-2012, was anchored across the southwest U.S. with broad southwest flow aloft evident from the southwest U.S. toward the mid-Atlantic. A summer-like Bermuda high pressure area was anchored off the southeast U.S. coast. A stationary front extended across the lower Mississippi valley toward the mid-Atlantic with a cold front approaching from the west of this region from Texas toward the Great lakes. The air mass across the region in advance of the stationary front was extremely moist, warm, and unstable for mid-December. As an embedded strong short wave traversed the region in the southwest flow aloft, a period of strong shear and marginal instability translated across the region during the late afternoon and early evening. These synoptic features supported a strong to severe quasi-linear convective system, or squall line, which moved across the state from west to east during the late afternoon and evening. The line of thunderstorms spawned a half-a-dozen tornadoes causing extensive damage across several counties from west central into northwest and north central Georgia. As the line moved east past Atlanta, it weakened considerably and no further severe weather was observed across east Georgia. The six tornadoes occurring on this date tied the record for the most tornadoes ever occurring during December within the Peachtree City, Georgia county warning area in December, namely six in 2005.