Thunderstorms developing along a stationary front across north Georgia produced isolated  reports of wind damage in a portion of the metro Atlanta area. This front also triggered training storms that quickly dumped several inches of rain over the two-county area. Flash flooding occurred late in the evening on September 7th and continued into the early morning hours on September 8th. Afternoon showers and thunderstorms re-fired on the afternoon of September 8th with isolated flash flooding occurring again over-soggy north Fulton county.

Thunderstorm Wind in COBB, GEORGIA
From 07-SEP-21 22:36:00 to 07-SEP-21 22:46:00 (EST-5)
Location: (MGE)DOBBINS AFB MAR
Magnitude: 50.00 EG
Property damage: 2.00K
Reported by: Emergency Manager

The Cobb County Emergency Manager reported a few trees blown down in east Cobb County on Somerset Court and along Shadowlawn Road.

Flash Flood in FULTON, GEORGIA
From 07-SEP-21 22:58:00 to 08-SEP-21 05:30:00 (EST-5)
Location: ROSWELL
Flood cause: Heavy Rain
Property damage: 60.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Emergency Manager reported flooding over portions of north Fulton county due to quickly accumulating rainfall over the area.  Radar estimates indicate 3 to 6 inches of rain occurred over the area, resulting in the flash flooding. According to the NOAA Atlas 14, these rainfall amounts have a 0.5% to 0.2% chance of occurrence in a given year.
The Emergency Manager reported flash flooding at the intersection of Willeo Road and Azalea Drive, Haynes Bridge Road and Westside Parkway, and Riverside Road along the Chattahoochee River. Flooding at Encore Parkway at North Point Center East caused at least one vehicle to stall in the intersection.

Flash Flood in COBB, GEORGIA
From 07-SEP-21 22:30:00 to 08-SEP-21 07:30:00 (EST-5)
Location: MARIETTA
Flood cause: Heavy Rain
Property damage: 1.94M
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous social media posts and reports from Emergency Management indicated significant flooding over Cobb county due to anomalously heavy rainfall.
Radar estimates indicate 5 to 7 inches of rain accumulated quickly over the area resulting in the flash flooding. These amounts are between 0.1% and 0.2% chance of occurrence in a given year according to the NOAA Atlas 14.
In total, more than 250 structures, 15 roadways and more than 100 cars were inundated with floodwater. The Emergency Management reported flooding of the Roswell Road and Old Canton Road intersection, a washout of East Lake Parkway, a washed out footbridge near Chinquapin Drive and South Woodland Drive, and complete collapse and washout of Pickens Industrial Drive.
Additionally, dozens of cars were flooded in the parking lot of the Marietta Crossing Apartment homes due to flash flooding of Rottenwood Creek. Water also caused damage to the interior of the building after water inundated the apartments.
Flash flooding occurred along Columns Drive along the western bank of the Chattahoochee River, inundating multiple homes and vehicles. This flooding was also documented by a local news station traffic helicopter on Twitter.
The river gage on Sope Creek (NWS MARG1/USGS 02335870) recorded an almost 17 foot rise in 4 hours due to the quickly accumulating rainfall. The observed stage height crest in Major Flood Stage at 18.05 feet -- only 0.3 feet below the crest from the historic September 2009 floods. Two river gages on the Chattahoochee River in Vinings (NWS VING1/USGS 02336000  and NWS VIXG1/USGS 02335990) also rose above flood stage.

Flash Flood in FULTON, GEORGIA
From 08-SEP-21 17:56:00 to 08-SEP-21 23:00:00 (EST-5)
Location: ALPHARETTA
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Emergency Manager reported more than a foot of water covering the roadway at the intersection of Windward Plaza and Windward Parkway with at least one stalled vehicle in the water. Water was also reported over the roadway at Academy Street.
Radar estimates indicate between 0.5 and 1 inch of rain occurred in the afternoon of September 8, but with already soggy soils from the previous 24-hours, this rainfall was enough to trigger additional flash flooding.

Thunderstorm Wind in FULTON, GEORGIA
From 07-SEP-21 22:01:00 to 07-SEP-21 22:42:00 (EST-5)
Location: RED OAK
Magnitude: 50.00 EG
Property damage: 12.00K
Reported by: Emergency Manager

The Fulton County Emergency Manager and local utility companies reported several trees and power lines blown down across the area from College Park to Alpharetta.