Thousands Without Power, Flash Flood Warning Issued For Cobb

KENNESAW, GA -- Strong storms tore through parts of Cobb County and metro Atlanta Wednesday morning, knocking out power to about 4,500 customers, according to Georgia Power.

The National Oceanic and Atmospheric Administration released a Special Weather Statement as part of a Significant Weather Advisory on Wednesday afternoon, saying that the situation in Cobb and adjoining counties could produce winds up to 40 mph as well as "penny-sized hail."

"Expect minor damage to tree limbs and blowing around of light ... unsecured objects," the administration said, adding that a strong thunderstorm was moving through Brownsville and headed to Douglasville.

"Some locations in the path of this storm include Atlanta, Marietta, Douglasville, Sandy Springs, Smyrna, Kennesaw, Powder Springs, Austell, Hiram, Lithia Springs, Fair Oaks, White Water Park, Lost Mountain Park, Vinings, Brownsville, Jim R Miller Park, Due West, Bolton, Dobbins Air Reserve Base and Mableton," the agency said.

Read more: Strong storms, floods batter Norcross

The administration advised that anybody outdoors should seek shelter inside immediately.

Cobb was under a flash flood warning until 4:45 p.m., the National Weather Service announced.

"Some locations that will experience flooding include... Marietta, Roswell, Smyrna, Kennesaw, Acworth, Powder Springs, Austell, Fair Oaks, Lithia Springs, Mount Bethel, White Water Park, Sweat Mountain, Lost Mountain Park, Kennesaw State University, Vinings, Jim R Miller Park, Six Flags Over Georgia, Due West, Sandy Plains and Dobbins Air Reserve Base. Allatoona Creek at Mars Hill is expected to rise above flood stage," the service said.

A tornado watch was in effect for much of the metro area, but it expired at 1 p.m.

Marietta police sent a traffic advisory shortly Wednesday afternoon, saying that traffic lights were out but had been restored at Roswell Road and Cobb Parkway. Officers were on the scene directing traffic.

In Austell, Six Flags Over Georgia was closed for the day and, in Augusta, the Masters Par-3 Contest — the traditional kick-off of the major golf tournament — was facing postponement due to the storms.

"When you experience an outage keep in mind that we are working ... our crews are ready to be deployed, but the thing with this storm is we can't deploy them into your neighborhood until it is safe to do so, until those winds die down," a Georgia Power spokeswoman said in a video posted on Twitter.

Read more: Tornadoes, hail possible as storms roll through Georgia

At Hartsfield-Jackson Atlanta International Airport, a ground stop was issued by the Federal Aviation Administration shortly before 9 a.m.

A video posted on Twitter showed large hail on the ground in Marietta.

Read more: Tips for safety during a tornado

Utility systems around the metro area also reported about 3,000 outages, according to WXIA.

This is a developing story. Stay with Patch.com for the latest.