The National Weather Service, has issued a flood watch for Cobb County and most of the rest of the region starting midnight tonight and in effect through tomorrow evening.
What is in the Flood Watch?
The flood watch statement had the following information:
…FLOOD WATCH IN EFFECT FROM MIDNIGHT EST TONIGHT THROUGH TUESDAY
EVENING…
* WHAT…Flash flooding caused by excessive rainfall continues to be
  possible.
* WHERE…Portions of central, east central, north central,
  northeast, northwest, and west central Georgia, including the
  following areas, in central Georgia, Butts, Jasper, Monroe and
  Putnam. In east central Georgia, Greene. In north central Georgia,
  Barrow, Cherokee, Clayton, Cobb, DeKalb, Douglas, Fayette,
  Gwinnett, Henry, Morgan, Newton, North Fulton, Rockdale, South
  Fulton and Walton. In northeast Georgia, Clarke, Jackson, Madison,
  Oconee and Oglethorpe. In northwest Georgia, Bartow, Carroll,
  Catoosa, Chattooga, Dade, Floyd, Gordon, Haralson, Murray,
  Paulding, Polk, Walker and Whitfield. In west central Georgia,
  Coweta, Harris, Heard, Lamar, Meriwether, Pike, Spalding, Talbot,
  Troup and Upson.
* WHEN…From midnight EST tonight through Tuesday evening.
* IMPACTS…Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Storm drains and ditches may become clogged with debris.
* ADDITIONAL DETAILS…
  – Rainfall will overspread the watch area tonight through
    Tuesday evening and may be heavy at times. Heaviest rain will
    be during the morning to afternoon hours Tuesday as a front
    moves through the area with a line of thunderstorms ahead of
    it. Rainfall amounts of 2-4 inches are expected, but locally
    higher amounts will be possible, especially along the
    southward facing slopes of the NE Georgia…
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