EF1 tornado, St Charles, Georgia, December 22, 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

December 22, 2011

Touchdown

5:44 PM EST (22:44 UTC)

Lifted

5:46 PM EST (22:46 UTC)

On the ground

2 minutes

Path length

1.1 miles (1.7 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$150,000

County

Coweta County

Touchdown point

33.266, -84.800

Lift-off point

33.273, -84.783

Record number

1112221644-01

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.

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].

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

0 minutes of warning. NWS FFC issued a tornado warning for this county at 22:44 UTC, 0 minutes before the tornado touched down, in force until 23:30 UTC.

The county was under a tornado watch, issued at 20:25 UTC and running to 00:02 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:51 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 Atlanta radar (KFFC), 23 km away, was scanning. The volume nearest the touchdown began at 22:44 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

12 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.