171
FXUS62 KFFC 230304
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
1004 PM EST Fri Nov 22 2024



.UPDATE...
Issued at 933 PM EST Fri Nov 22 2024

Forecast challenge for the overnight hours will be how far south
the bkn/ovc cloud deck will make it from the north. Latest
satellite imagery shows a deck of stratocu surging southward from
TN into northern GA. The models have picked up on the clouds, but
not necessarily the speed at which the deck is pushing south. Do
think the clouds will reach the northern burbs of Atlanta. Not
confident that the southern edge will remain intact, it could be
more sct by the time it make it to ATL. Have increased the sky
cover grids a bit to account for the cloud deck trends. Will have
to watch MinT values where the clouds are a bit thicker than
previously forecast.

&&

.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...
(00Z TAFS)
Issued at 556 PM EST Fri Nov 22 2024

Winds will remain on the west side. Elevated speeds again
overnight with gusts diminishing a few hours after sunset. Some
low end gusts will be possible again tomorrow. Some few/sct cu
possible just before 12Z SAT.

//ATL Confidence...00Z Update...
High confidence all elements.

NListemaa

&&

.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...NListemaa
LONG TERM....King
AVIATION...NListemaa