report updated 4/13/98
Preliminary Synoptic Background
An upper level low pressure system with strong dynamics and energy moved into the Ohio and Tennessee valleys Wednesday night, April 8 which increased instability. A strong southerly low level jet of 50 to 60 knots prevailed over Georgia providing strong warm air advection and increasing moisture. The polar and subtropical jets had generally merged over the southern states with wind speeds greater than 150 knots. The models forecast CAPE to increase to the 1000-1500 (j/kg) range, while ground relative helicity was to reach a maximum above 700 m²/s² between 8 pm Wednesday and 2 am Thursday. This set of parameters and features prompted the Storm Prediction Center in Norman, OK to place the north half of Georgia in a moderate to high risk of severe weather for Wednesday night, and tornado watches were issued.
The same "supercell" thunderstorm (or thunderstorm complex) that produced the deadly F5 tornado near Birmingham, Alabama early Wednesday night later moved across northern Georgia. It entered Haralson County, Georgia about 1120 pm EDT April 8...and continued on an east-northeast course through the northern part of the Atlanta Metropolitan Area after midnight... and then weakened as it moved into Northeast Georgia between Gainesville and Athens. During its lifetime in Georgia, it produced damaging winds...and apparently 3 tornadoes.
Survey of Damage
Meteorologists Patricia Hart and Kent Frantz surveyed the damage from the air with Captain Bob Coats of the Georgia Civil Air Patrol. They flew to Haralson County where the first tornado struck as confirmed by Frank Taylor of the Peachtree City National Weather Service office, who was surveying the area from the ground. They agreed with Mr. Taylor that the damage from near the Alabama state line to just west of Tallapoosa was caused by an F1 tornado. Over 30 buildings...including mobile homes...churches and a strip mall were damaged. No injuries were reported. The path length was 3.5 miles and the width averaged 200 yards.
The air survey crew followed the path of the "supercell" noticing only a few trees blown down in southern Paulding County before reaching Smyrna in Cobb County, Georgia. A ground survey team of meteorologists Dean Hutsell and Pat Murphy also reviewed this site with the assistance of Lt. Mark Gresham of the Cobb County Fire Department. The survey teams determined that another tornado touched down around the Windy Hill Road and Cobb Parkway intersection, and continued to just across the Chattahoochee River in Fulton County near Interstate 285. At least 30 buildings were damaged. Some suffered heavy damage...including a service station and a car dealership. No injuries were reported. Tornado intensity was rated F2. Path length was approximately 3 miles and width was 100 to 200 yards.
The survey teams moved to Dekalb and Gwinnett Counties where a third tornado occurred. The damage path begins just northeast of Perimeter Mall in the Dunwoody area and extends well into Gwinnett County. The ground survey team was assisted by meteorologist Dan Graff of The Weather Channel who was familiar with the damaged area. There was widespread significant damage to trees and homes. At least 5 thousand homes were affected. One person was killed in Dekalb County when a tree fell through the roof of a home. The number of injuries is not known at this time. Tornado strength has been rated at the top of the F2 range, with maximum winds around 150 miles an hour. The path length was 19 miles and the width was around one half mile.