TL;DR: Life-threatening flash flooding was already occurring in Clayton, southwestern DeKalb and south-central Fulton counties on September 11, 2026, with a warning in effect until 10:30 p.m. EDT and flooded interstates near Atlanta.

Warning remained in effect until 10:30 p.m.

The National Weather Service office in Peachtree City issued a Flash Flood Warning for Clayton County, southwestern DeKalb County and south-central Fulton County in north central Georgia, valid until 10:30 p.m. EDT on Friday, September 11, 2026, according to the National Weather Service posting titled "Flash Flood Warning issued September 11 at 4:34PM EDT until September 11 at 10:30PM EDT by NWS Peachtree City GA."

That initial bulletin was released at 4:34 p.m. EDT. Doppler radar indicated thunderstorms delivering heavy rain across the warned area at that time. Between 1.5 and 2.5 inches of rain had fallen, and another 1 to 2 inches was possible in the warned area. The bulletin stated that flash flooding was ongoing or expected to begin shortly.

The described hazard was flash flooding caused by thunderstorms. Radar was listed as the source. The expected impact was flooding of small creeks and streams, urban areas, highways, streets and underpasses, along with other poor-drainage and low-lying areas.

A follow-up National Weather Service posting titled "FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT THIS EVENING FOR CLAYTON, SOUTHWESTERN DEKALB AND SOUTH CENTRAL FULTON COUNTIES" raised the urgency. At 4:56 p.m. EDT, emergency management reported thunderstorms producing flash flooding in north Clayton and south Fulton counties, including at the interchange of Interstate 85 and Interstate 285 and also near Forest Park.

In that update, observed rainfall had increased to between 2 and 3 inches. An additional 1 to 2 inches remained possible. The bulletin stated that flash flooding was already occurring. The hazard was described as life-threatening flash flooding from thunderstorms producing flash flooding, with emergency management as the source. The listed impact was life-threatening flooding of creeks and streams, urban areas, highways, streets and underpasses.

Coverage from CBS Atlanta titled "Flash flood warnings issued for Hartsfield-Jackson airport and parts of metro Atlanta" reported that heavy rain was already flooding parts of metro Atlanta on September 11. That report, updated at 4:47 p.m. EDT, said the Peachtree City warnings covered Hartsfield-Jackson Atlanta International Airport and several communities south and west of the city. It also confirmed the 1.5 to 2.5 inches measured by 4:34 p.m. and the possible additional 1 to 2 inches.

Neighborhoods and airport named in alert

The warning named 18 locations that would experience flash flooding, according to the National Weather Service postings. Those places were Atlanta, Jonesboro, City of South Fulton, East Point, Union City, Forest Park, Riverdale, College Park, Morrow, Hapeville, Lake City, Hartsfield-Jackson Airport, Conley, Fort Gillem, Lakewood Park, Ellenwood, Gresham Park and Rex.

The CBS Atlanta report highlighted a shorter group for households checking travel plans: parts of Atlanta, East Point, Union City, College Park, Hapeville, Jonesboro, Riverdale, Forest Park and the airport. For families near the airport, the inclusion of Hartsfield-Jackson Airport meant terminal access roads, pickup lanes, parking lots and nearby interstates could become hazardous during downpours.

The later emergency-management update narrowed observed flooding to north Clayton and south Fulton counties. It specifically identified the interchange of I-85 and I-285 and the Forest Park area. Residents in low spots near creeks, underpasses, service roads and poorly drained streets faced the highest near-term risk.

Preparedness guidance in the National Weather Service bulletins told motorists to turn around rather than enter flooded roads. The bulletins stated that most flood deaths occur in vehicles. They also advised people to be aware of surroundings, avoid driving on flooded roads, and report observed flooding to local emergency services or law enforcement when it could be done safely, with a request that officials pass the information to the National Weather Service.

Interstates and local roads flooded

Road impacts developed quickly during the afternoon commute window. Reporting from WSB-TV Channel 2 titled "Major roadways around metro Atlanta see flooding as storms move through" said heavy rainfall created hazardous conditions and temporarily shut down two major roadways.

According to that WSB-TV timeline, all lanes of Interstate 285 westbound at Interstate 85 were closed because of flooding. A separate entry at 5:07 p.m. described a black sedan stranded in a flooded tunnel on Interstate 85 south at I-285 at mile marker 70. At 4:53 p.m., flash flooding was reported in Clayton County, with water covering the roadway at Courtney Drive near Finley Drive.

A WSB Radio report titled "Heavy rain and flash flooding impact metro Atlanta roads and travel" said flooding forced closure of the Interstate 285 westbound ramp to Interstate 85 southbound in Fulton County near Hartsfield-Jackson Atlanta International Airport. It also reported standing water heavily affecting traffic on GA 400 southbound near Northridge Road in Sandy Springs.

The WSB-TV timeline added that Georgia 400 South was shut down between Holcomb Bridge Road and Northridge Road because of flooding. Flooding was also reported on Georgia 400 in Roswell and Dunwoody, near Roberts Drive and Northridge Road. At 7:24 p.m., three lanes of Georgia 400 southbound at Holcomb Bridge Road remained closed, while earlier problems on Interstate 285 appeared to have cleared, according to information attributed to 511GA.org.

For household planning, the pattern was clear: avoid interstate exchanges beside the airport, avoid dips and tunnels on I-85 and I-285, and avoid GA 400 near Holcomb Bridge, Northridge, Roberts Drive, Roswell, Dunwoody and Sandy Springs during intense rain. Transportation officials were tracking additional reports of high water and localized street flooding as storms persisted, according to the WSB Radio report.

Airport ground stops lengthened delays

Air travel through Hartsfield-Jackson Atlanta International Airport was disrupted by thunderstorms. The WSB-TV report said a ground stop for departures later expired, but delays continued.

Its timeline stated that the Federal Aviation Administration issued a ground stop that was extended from 4:45 p.m. to 5:45 p.m., then extended again. Departure delays averaged about 45 minutes and were expected to increase. By 5:23 p.m., average departure delays reached 75 minutes and were increasing. At 6:40 p.m., the ground stop expired while the ground delay reached 107 minutes.

The WSB Radio report likewise linked ground stops and departure delays at the Atlanta airport to nearby thunderstorms. Travelers with evening flights needed backup plans for rides, parking, meals, medication timing, child care and overnight supplies if return travel became impossible.

Households expecting arriving relatives should not wait beside flooded airport approaches. A safer approach was to track flight status, wait at higher ground away from the interchange zone, and confirm that exit routes were open before driving toward I-85, I-285 or airport connector roads.

Additional warnings covered wider metro

The Clayton-DeKalb-Fulton warning was only one part of a broader flood episode. CBS Atlanta reported a separate flash flood warning in effect until 10:30 p.m. for northern Carroll, Haralson, southern Paulding and northwestern Douglas counties.

In that western zone, between 2.5 and 4 inches of rain had fallen near the Interstate 20 and Villa Rica Highway interchange by 4:38 p.m., with another 1 to 2 inches possible. Flash flooding was already occurring there. The warning included Douglasville, Villa Rica, Bremen, Temple, Tallapoosa, Buchanan, Waco, Lithia Springs and nearby communities.

The WSB-TV timeline listed more evening alerts. A flash flood warning was issued for Carroll, Douglas, Haralson and Paulding counties until 10:30 p.m. Later, a flash flood warning was issued for Cobb and Fulton counties until 11:15 p.m., followed by a warning for DeKalb, Newton, Rockdale and Walton counties until 11:15 p.m. An additional flash flood warning covered Gilmer, Gordon and Pickens counties until 12:45 a.m. Saturday.

Other storm effects extended beyond flooding. The timeline noted a severe thunderstorm warning for Gilmer, Gordon and Pickens counties until 7:30 p.m., plus incoming reports of trees down in Gilmer County. Separately, flooding was reported in Villa Rica, where a viewer shared video of water overflowing into a backyard.

What households should do during warning hours

Do not walk, swim or drive through floodwater. The National Weather Service bulletins emphasized turning around when encountering flooded roads and avoiding driving on flooded routes. Vehicles can lose traction or stall in shallow moving water, and roadbeds beneath water may be washed out.

Move to higher ground if water rises near a home, apartment lot, creek, drainage ditch or underpass. Avoid basements, sunken garages and tunnels during rapid rises. Keep flashlights, charged phones, important documents in waterproof storage, drinking water, ready food, prescription medication and infant or pet supplies where they can be reached without entering flooded areas.

Check local conditions before evening travel. The WSB Radio report urged drivers to avoid standing water, allow extra travel time and seek alternate routes through affected areas. Do not rely on following another vehicle through a flooded section. If a car stalls in rising water, leave it and move to higher ground when it can be done safely.

CBS Atlanta said the CBS News Atlanta NEXT Weather team had issued NEXT Weather Alerts for Friday and Saturday afternoons as heavy rain and strong storms moved through North Georgia. A front was expected to bring scattered showers and thunderstorms, with heavy downpours the greatest threat. Rain could accumulate quickly and cause localized flooding, while some storms could produce strong winds.

Most storms were expected to develop after 2 p.m. Friday and Saturday. The wet weather could affect outdoor activities, including Saturday's Georgia game at Sanford Stadium and the Georgia Tech game at Bobby Dodd Stadium. Fans heading to either game were advised to bring a poncho and prepare for possible storms. Temperatures were expected to remain above average, with highs near 90 degrees and into the low 90s, compared with an average high of 85 degrees for metro Atlanta. Most rain and storms were expected to move out by the beginning of the workweek.

Sources referenced