835
FXUS62 KFFC 111731
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
131 PM EDT Sat May 11 2024

...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Sunday)
Issued at 353 AM EDT Sat May 11 2024

Key Messages:

 - Fair weather and near to slightly below average temperatures
   will occur this weekend.

 - Very light terrain induced showers or drizzle may occur in the
   mountain of north Georgia this evening.

Thoughts on the Weekend:

Over the course of the weekend, a surface high and upper level ridge
will gradually shift from the Southern Plains into the Southeast.
This transition will result in predominantly dry weather and near to
slightly below average temperatures. Widespread high temperatures in
the upper 70s are expected today, while Sunday should see highs near
80 degrees in the region. Northwest winds will prevail in the region
again today with gusts in the 20 to 25 mph range expected this
afternoon. Low level moist advection associated with the prevailing
northwest flow and upslope flow could produce a few light showers or
drizzle along the northwest oriented slopes of the north Georgia
mountains this evening. Any accumulations should be very light (a
trace to 0.10 inches). Winds will be lighter in the region on Sunday
as the surface high settles over Alabama and Georgia.

Albright

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 353 AM EDT Sat May 11 2024

Model agreement across much of the long term is surprisingly high
across the board given a cut off upper level low parked over the SW
CONUS. Said low is forecast to slowly progress to the east over the
coming days and be the primary weather marker through much of the
long term forecast period. Lee cyclogenesis will take place over the
southern Great Plains as the upper level low moves by while our post
frontal airmass modifies and slides east. Southerly flow will begin
by Sunday night into Monday, bringing with it the lovely gulf
moisture back into the CWA. Divergent flow aloft and WAA mean rising
air and rain and thunderstorm chances returning to the area. Looking
at the deterministic models, several rounds of rainfall will be
possible Monday and Tuesday. Given that post frontal airmass will
still be in place through at least part of Monday, isentropic lift
with more light to moderate rain seems to be more likely, though some
embedded convective elements may be present with some forecast
elevated instability. By Tuesday, a front will be pushing towards the
area driven by surface low approaching to NW, which should allow for
deeper moisture return at the surface and possible thunderstorms.
This day has the potential for some severe weather, given moderate
CAPE and shear values shown within some of the models, but there are
so many potential failure modes with this (short time for moisture
return, overall timing with the diurnal cycle, nature of upstream
convection, lack of convergence along frontal boundary) that
confidence is far too low to make any real mention of it yet.

The other side of this system will be the rainfall and the potential
for any flooding/flash flooding. Current QPF values are 1-2"
primarily over central Georgia (with some locally higher amounts
possible) and 0.5"-1" over north Georgia. These forecast values
likely wouldn`t result in much if any flooding/flash flooding except
in any locations that did receive repeated rounds of convective
rainfall.

This system exits into Wednesday, but our lull in the rain chances
is brief as yet another system follows in behind this one. Once
again, model consensus remains surprisingly good for these lows
traveling within the southern branch of the Pacific jet, though some
timing differences do exist at this juncture. Best timing looks to be
Thursday night into the day on Friday for this round of rain and
potential thunderstorms. This is a bit too far in the future to
discuss specifics, but this would be a third round of widespread rain
and thunderstorms in a week across the CWA, so we`ll need to monitor
the hydro side of things given our soils and rivers, creeks, and
streams may be a bit more sensitive to heavy rainfall.

Lusk

&&

.AVIATION...
(18Z TAFS)
Issued at 126 PM EDT Sat May 11 2024

VFR conditions will continue across the area. A brief period of
NW wind gusts to 18 knots are expected this afternoon, then winds
will mostly decouple during the early evening hours. Few to
scattered cumulus clouds will dissipate by evening as daytime
heating ends.

//ATL Confidence...18Z Update...
High for all elements.

SEC

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          54  81  55  76 /   0   0   0  50
Atlanta         56  80  60  74 /   0   0   0  70
Blairsville     47  74  51  71 /  30   0   0  60
Cartersville    51  79  56  74 /  10   0   0  70
Columbus        58  84  62  78 /   0   0  10  70
Gainesville     54  79  58  73 /   0   0   0  60
Macon           56  82  59  78 /   0   0   0  70
Rome            51  81  56  75 /  10   0  10  70
Peachtree City  55  81  58  76 /   0   0   0  70
Vidalia         59  83  62  81 /   0   0   0  60

&&

.FFC WATCHES/WARNINGS/ADVISORIES...None.

$$

SHORT TERM...SEC
LONG TERM....Lusk
AVIATION...SEC