EF2 tornado in Upson County, Georgia

A survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia confirmed that the EF2 tornado that first touched down in northeast Harris county around 1155 pm EDT continued across southern Meriwether and into far northwest Upson county before finally lifting approximately nine miles northwest of Thomaston. The tornado had a path length of just over four miles within Upson county, while the total tornado path length was on the order of 24 miles. The maximum path width was 880 yards or less at this point with maximum winds estimated to be 130 mph. Within Upson county, the tornado traveled through a mostly rural forested area and as such structural damage was minimal. However, two structures were destroyed, four suffered major damage, and 6 others sustained minor damage. Thousands of trees were damaged or destroyed, along with several power lines. Some outbuildings were also damaged or destroyed. There were no fatalities or injuries reported from this tornado along its path, including Upson county. It should be noted, however, that this same thunderstorm spawned yet another tornado in Lamar county upstream that killed two people.

[04/27-04/28/11: Tornado #10, County #3-3, EF2, Harris-Meriwether-Upson, 2011:019].

A highly diffluent, deep upper trough, centered across Texas, took on a negative tilt and began to rotate northeast during this period. A strong maritime-Pacific (mP) cold front accompanied the upper trough through the mid-south into the southeast from the early morning hours of the 27th to the early morning hours of the 28th. An intense low-level jet with winds in excess of 70 knots was noted in advance of this system and tracked across the mid-south early on the 27th, across north Alabama and north Georgia into the early morning hours of the 28th. West-southwest winds aloft were highly diffluent and near 200 mph across this same region. The strong low-level jet brought unseasonably, warm, moist Gulf air northward in advance of the mP cold front. Dewpoints in the 70s and maximum temperatures in the 80s combined with the extremely strong low-level and upper jets to create an almost perfect environment for severe thunderstorms and large devastating tornadoes. Indeed, the tornado outbreak that affected much of the eastern U.S., but particularly the south central and southeastern U.S. during this period, was unprecedented and likely the largest recorded in U.S. history. The tornado outbreak that accompanied this combination of weather features has been termed the 2011 Super Outbreak, an outbreak even worse than the 1994 and 1974 super tornado outbreaks across the eastern U.S. The outbreak affected the South Central, Southeast, Midwest, and even the usually less tornado prone Northeastern United States. Over 330 tornadoes were reported during this outbreak which began on April 25th and continued into the 28th affecting 21 states from Texas to New York. Even isolated tornadoes were noted in Canada. Nearly 350 people died from these tornadoes, of which over 230 of these were in Alabama alone. Four tornadoes on April 27th in Alabama and Mississippi were ranked EF5, the highest tornado damage rating on the Enhanced Fujita Scale. On average, there is only one EF5 tornado per year in the entire U.S.

Widespread and destructive tornadoes occurred on each day of the outbreak, but April 27th was clearly one of the most prolific and destructive tornado days in U.S. history, probably only surpassed by the Tri-State outbreak of 1925 and the Tupelo-Gainesville outbreak of 1936. The 24-hour period from 8 am April 27th to 8 a.m. April 28th is listed by the National Oceanic and Atmospheric Administration (NOAA) as the fourth deadliest tornado outbreak in U.S. history, with the 24 hours commencing April 28th at 8 a.m. as the fifth deadliest tornado day in U.S. history. It has also been determined to be the costliest tornado outbreaks and one of the costliest natural disasters in the U.S., even after adjustments for inflation, with total damages estimated to exceed $10 billion.

Georgia was heavily impacted by this tornado outbreak, especially the northwest part of the state which bore the brunt of the massive supercell thunderstorms producing killer tornadoes that tracked east-northeast from northern Alabama during the late evening. All together, there were 15 tornadoes affecting 28 counties within the Peachtree City, Georgia 96-county warning area (CWA) of North and Central Georgia. All of these occurred within a 24-hour period commencing at 8 am April 27th. One of these tornadoes was rated an EF4, the first EF4 tornado in Georgia since the Palm Sunday outbreak in 1994. In addition, there were also four EF3 tornadoes. Fifteen tornado-related deaths were observed in north and central Georgia, the most tornado-related deaths within the Peachtree City, Georgia forecast area since its inception in 1994. The previous highest tornado-related death total was 12 on March 20, 1998, when a tornado struck Gainesville, Georgia.

Finally, it should be noted that while the most significant period of severe weather during this outbreak for Georgia was from the afternoon of the 27th through the early morning hours of the 28th, there was an initial round of severe weather across northwest Georgia early on the 27th as a decaying line of severe thunderstorms moved into the region from northeast Alabama. Widespread wind damage and even a few brief weaker tornadoes accompanied this system into the northwest counties of the state.