Severe Storm and Heavy Rain Potential for Sunday
Isolated Severe Thunderstorms are possible across North Georgia Saturday Night – Sunday Morning, generally north of the I-85 corridor. Expect an ongoing line of thunderstorms (squall line) to push into Northwest Georgia early Sunday morning between midnight and 4 am Sunday. A strong area of enhanced winds just above the surface (low level jet) will support the potential for strong wind gusts embedded within the squall line, especially where bowing segments are noted. The strong low level winds could also support an isolated tornado early Sunday morning along or just ahead of the line of storms. The squall line should weaken and begin to slow down by late Sunday morning or early Sunday afternoon as the greater upper forcing lifts further north. Therefore, the potential for severe storms south of the I-85 corridor should greatly diminish by Sunday afternoon as the squall line weakens. See the attached graphic for better timing across North GA.
Moderate to Heavy Rain is expected across North and Central Georgia from Saturday evening through Sunday afternoon. At this time we are expecting widespread rainfall amounts of 1 to 2.5 inches… with the greater amounts centered along a line from Columbus to Atlanta to Gainesville. Although most areas should be able to handle these rainfall amounts, ample runoff will cause rises on rivers and creeks and could result in isolated areas of minor flooding. Especially vulnerable will be Big Creek from Cumming to Alpharetta. A Flood Watch may be issued on Saturday if higher rainfall amounts are expected.
Confidence. There is still moderate uncertainty with exact timing and strength of the expected squall line early Sunday morning. Please stay tuned to later forecast as fine tuning of timing and severity will continue through Saturday afternoon with later model runs. At this time, we plan to keep our partners informed through special emails and graphical products posted to our webpage, social media, and other local media outlets.