118
FXUS62 KFFC 111043
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
643 AM EDT Sat May 11 2024


...New 12Z 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...
(12Z TAFS)
Issued at 637 AM EDT Sat May 11 2024

VFR conditions (SKC-SCT AOA 5000 ft AGL and unrestricted
visibility) will dominate in the region through at least 18Z
Sunday. Northwest winds will arrive after 15Z today and linger
through at 01Z Sunday. Peak wind gusts in the 20 to 25 kt range
are possible, mainly in northern Georgia, between 17Z today and
00Z Sunday. The higher terrain of north Georgia may experience
patch MVFR conditions (ceilings 2000-3000 ft AGL) and light rain
showers/drizzle between 22Z today and 06Z Sunday.

//ATL Confidence...12Z Update...
Overall confidence in the KATL TAF is high.

Albright

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          54  81  55  76 /   0   0   0  40
Atlanta         56  80  60  74 /   0   0   0  50
Blairsville     47  74  51  71 /  30   0   0  40
Cartersville    51  79  56  74 /  10   0   0  50
Columbus        58  84  62  78 /   0   0  10  60
Gainesville     54  79  58  73 /   0   0   0  40
Macon           56  82  59  78 /   0   0   0  50
Rome            51  81  56  75 /  10   0  10  50
Peachtree City  55  81  58  76 /   0   0   0  50
Vidalia         59  83  62  81 /   0   0   0  40

&&

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

$$

SHORT TERM...Albright
LONG TERM....Lusk
AVIATION...Albright