EF0 tornado, Roundtop to Ratcliff, Georgia, April 4, 2011

1. EF065 to 85 mphthis tornado

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mph

   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

EF0

Date

April 4, 2011

Touchdown

9:34 PM EDT (01:34 UTC)

Lifted

9:36 PM EDT (01:36 UTC)

On the ground

2 minutes

Path length

1.8 miles (2.9 km)

Path width

880 yards (805 m)

Deaths

0

Injuries

0

Property damage

$500,000

County

Gilmer County

Touchdown point

34.721, -84.604

Lift-off point

34.734, -84.576

Record number

1104041934-01

An extremely progressive and highly kinematic upper flow remained in place across the U.S. A deep, full-latitude negatively tilted trough and associated strong Pacific cold front swept through the eastern U.S. April 4th into April 5th. An intense northeast to southwest oriented squall line of thunderstorms accompanied this front. Wind gusts of 60 to 70 mph were common along this line of thunderstorms as it traversed the entire Peachtree City (WFO FFC), Georgia Weather Forecast county warning area. Nearly every county received at least one severe thunderstorm warning during this event and nearly every county experienced extensive wind damage from these thunderstorms. Two brief EF0 tornadoes also occurred with this event in Gilmer county of north central Georgia. Downed trees on homes and vehicles also caused 7 fatalities during this event, the most in any single weather event since the catastrophic floods of late September 2009. Even several hours after the storms had passed, at least 50,000 residents of north and central Georgia remained without power.

A survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia in conjunction with the Gilmer County Emergency Management Director confirmed that a brief EF1 tornado, sandwiched between two microbursts, had touched down in west central Gilmer county approximately 3.5 miles southeast of Tails Creek or just northeast of Carters Lake and traveled east-northeast 2.6 miles before lifting. The maximum path width was determined to be 1/2 mile wide with maximum winds estimated to be 100 mph. Hundreds of trees were either blown down, uprooted, or snapped along the path of the tornado as it traveled through the Rose Garden subdivision. Approximately 100 homes in this area sustained at least minor damage as large trees fell on the structures. Several sustained major damage. There were reports from Atlanta television media that several people were trapped in their homes during this event, but this information was not confirmed. No injuries or fatalities were reported from this event.||[04/04-04/05/11: Tornado #1, County #1-1, EF1, Gilmer, 2011:003].

A damage survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia in conjunction with the Gilmer County Emergency Management Director confirmed that a second EF0 tornado, again in combination with two brief microbursts, touched down approximately two miles north-northeast of Tails Creek almost simultaneously with the EF1 tornado that touched down southeast of Tails Creek. This tornado also had a path width of 1/2 mile with maximum winds estimated to be 80 mph. This EF0 tornado tracked 1.9 miles east-northeast before lifting. Again, several hundred trees were either blown over, uprooted, or snapped along the path of the tornado. The event likely consisted of two brief tornado segments either side of a longer lasting microburst. Six chicken houses were either destroyed or heavily damaged. A horse stable was also destroyed. Three outbuildings were also heavily damaged. No damage to homes was observed from this tornado.||[04/04-04/05/11: Tornado #2, County #1-1, EF0, Gilmer, 2011:004].

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a tornado watch, issued at 22:00 UTC and running to 02:34 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:57 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 Northeast Alabama radar (KHTX), 138 km away, was scanning. The volume nearest the touchdown began at 01:35 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

42 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.