Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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519 FXUS62 KFFC 221857 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 157 PM EST Fri Nov 22 2024 ...Afternoon Area Forecast Discussion... .SHORT TERM... (This afternoon through Saturday) Issued at 156 PM EST Fri Nov 22 2024 Key Messages - A warming trend will begin Saturday and linger through the weekend. - Overnight lows in the 30s are expected tonight and Saturday night. Through Saturday Night: The longwave trough over the Northeast today will gradually drift towards the Canadian Maritimes during this period. As this occurs a a weak upper level ridge will develop over the Southeast. The ridge will be accompanied by a weak area of surface high pressure. These changes will help a warming trend develop in Georgia as the prevailing CAA (northwest winds) fades and heights rise. Compared to today, high temperatures on Saturday should be 4 to 8 degrees warmer. This should lead to widespread highs in the 55 to 65 degree range (1 to 4 degrees below seasonal averages). Continued upslope flow along the northwest slopes of the Appalachians should result in some low cloud cover tonight and Saturday morning in far northwest Georgia. Otherwise dry conditions and increasing upper level subsidence should produce cloud free skies. Conditions will be cold again tonight with overnight lows falling into the 30s across the state. The coldest conditions are expected in the mountains and along the Georgia/Alabama border where winds my be weaker overnight. Lows should be similar Saturday night, with light and variable winds working to combat any warming from the building ridge. Areas of frost and isolated freezing conditions will be possible both tonight and Saturday night. Albright && .LONG TERM... (Sunday morning through next Thursday) Issued at 156 PM EST Fri Nov 22 2024 As the extended period picks up on Sunday, surface high pressure will be positioned over the Southeast and gradually moving east towards the GA/SC Atlantic coast. Meanwhile, the northwesterly upper level flow that had steadily streaming in dry air aloft will be dampening over the course of the day, ultimately becoming quasi- zonal by early Monday. The steady warming trend from the short term period will continue on Sunday under clear skies and subsidence underneath the high. After the morning begins in the low to mid 30s across the majority of the forecast area, highs in the afternoon will climb into the low to mid 60s in north Georgia and upper 60s in central Georgia. On Monday, low-level flow will shift to southerly on the back side of the surface high. This, combined with the aforementioned quasi-zonal flow, will lead to advection of warm and moist air into the forecast area. Dewpoints in the low 40s on Monday morning will rise into the upper 50s by the end of the day. High temperatures on Monday will continue to warm, rising in to the upper 60s to mid 70s, which will be 6-12 degrees above climatological normals. Over the course of the day on Monday, a trough axis will swing through the Great Plains towards the Midwest, At this point it will become negatively-tilted and contribute to rapid development of a low pressure system over the Great Lakes region. A broad cold front extending from this low will approach far north Georgia late Monday night. Rain will spread into north and west Georgia in the region of forcing ahead of this front, reaching as far as a line from Columbus to Athens, with the most likely time window being the early morning hours on Tuesday morning. Forcing ahead of the front appears that it will significantly diminish in the morning, with rain chances subsequently coming to an end before the front clears the forecast area. Compared to the previous forecast, this loss of forcing is anticipated to be sooner than previously anticipated. Rainfall amounts associated with this system are forecast to be less than 0.25", with the highest amounts in the far northern tier. More substantial chances for areawide rainfall appear to be likely on Thanksgiving into Friday, as a slug of deep moisture spreads over the Southeast, followed closely by a surface low developing over the Tennessee Valley region. Uncertainty remains with respect to the position and evolution of this low. In general, it will likely intensify as it moves northeast towards the Mid-Atlantic, with a cold front extending into Georgia providing a focus for showers and some isolated thunderstorms within the deep moisture. Rainfall totals in association with this system will be more robust than the totals on Monday night/Tuesday morning, which will need to be monitored as guidance comes in to better agreement. As the cold front clearing out of the area by late Friday afternoon, a tight pressure gradient and strong northwesterly flow will bring in a noticeably colder airmass into next weekend. King && .AVIATION... (18Z TAFS) Issued at 1225 PM EST Fri Nov 22 2024 VFR conditions will prevail through 00Z Saturday. Areas of MVFR ceilings (1000-3000 ft AGL) may obscure the higher terrain of north Georgia between 00Z and 18Z Saturday. There is a small chance (20%) of these conditions reaching ATL briefly after 06Z. Winds will continue to be from the northwest with peak gusts in the 18 to 24 kt range through 23Z today, and between 14Z and 22Z Saturday. //ATL Confidence...18Z Update... High confidence in the KATL TAF. There is a small chance (20%) of ceilings in the 1000 to 3000 ft AGL range between 06Z and 14Z Saturday. Albright && .PRELIMINARY POINT TEMPS/POPS... Athens 37 61 35 66 / 0 0 0 0 Atlanta 37 57 37 64 / 0 0 0 0 Blairsville 32 54 31 64 / 0 0 0 0 Cartersville 33 57 31 64 / 0 0 0 0 Columbus 35 63 35 67 / 0 0 0 0 Gainesville 39 60 38 64 / 0 0 0 0 Macon 36 62 35 67 / 0 0 0 0 Rome 33 57 32 64 / 0 0 0 0 Peachtree City 34 59 33 65 / 0 0 0 0 Vidalia 38 62 37 68 / 0 0 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Albright LONG TERM....King AVIATION...Albright