EF1 tornado, Woodstock to Arnold Mill, Georgia, April 19, 2009

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 19, 2009

Touchdown

11:00 PM EDT (03:00 UTC)

Lifted

11:03 PM EDT (03:03 UTC)

On the ground

3 minutes

Path length

1.5 miles (2.3 km)

Path width

880 yards (805 m)

Deaths

0

Injuries

2

Property damage

$5.0 million

County

Cherokee County

Touchdown point

34.083, -84.456

Lift-off point

34.094, -84.435

Record number

0904192100-01

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.

Yet another deep upper trough was translating across the south central and southeast United States accompanied by a strong Pacific cold front. Although instability was marginal for the time of year, the upper atmosphere was highly sheared with a strong low-level jet. Showers and a few thunderstorms moved across the area during the day, but it was during the late evening hours when the front moved into the area from the west that strong to severe thunderstorms developed across eastern Alabama and moved into western Georgia. The activity took on the form of a squall line with distinct bowing segments. Two EF1 tornadoes were spawned within this line of thunderstorms causing considerable damage to homes and businesses in the Columbus and Woodstock areas. The activity quickly dissipated shortly after midnight as it moved further east into central and northeast Georgia.

A damage survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia confirmed that an EF1 tornado touched down in far southeast Cherokee county near the Cobb county line in the Woodstock area. The tornado touched down near the intersection of Georgia Highway 92 and Dial Drive, then continued north-northeast along Dial Drive crossing a large section of Coleman's Bluff. The tornado lifted just south of the intersection of Windcrest Court and River Chase Drive. The total path length of the tornado was 1.5 miles with a maximum path width of 1/2 mile or 880 yards. Maximum winds were estimated to be 90 mph. EF1 tornado damage to trees and structures was observed along a 3/4 mile-long path paralleling Dial Drive beginning just north of its intersection with Georgia Highway 92. Damage was observed to 120 homes along the path of the tornado, 12 of which were completely destroyed. The majority of the damage took place in the Coleman's Bluff area. Most of the damage was the result of large trees falling on the structures. Two residents of the affected homes were injured by debris.

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

20 minutes of warning. NWS FFC issued a tornado warning for this county at 02:40 UTC, 20 minutes before the tornado touched down, in force until 03:14 UTC.

The county was under a tornado watch, issued at 00:51 UTC and running to 05:30 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 00:48 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), 81 km away, was scanning. The volume nearest the touchdown began at 02:59 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 2009 tornado in GeorgiaEvery tornado in Georgia since 1950Warnings in force in Georgia nowThe forecast where you are

18 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.