235
FXUS62 KFFC 162341
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
741 PM EDT Fri May 16 2025

...New 00Z Aviation Discussion...

.SHORT TERM...
(This evening through Saturday)
Issued at 308 PM EDT Fri May 16 2025

Key Messages:

    - Temps in the upper 80s to low 90s (10-12 degrees above normal
      could lead to a record this afternoon for KATL.

    - Line of thunderstorms pushing through north Georgia, late tonight
      into tomorrow morning. (1AM-8AM for areas north of I-20).

Discussion:

Current stream of moisture coming from the Pacific ahead of the line
tonight is leading to the low clouds this morning from the SW and
the high level cirrus. Meanwhile the low pressure system that will
bring in our line of showers and thunderstorms overnight is
positioned over Minnesota with an attendant cold front through the
mid MS valley. This low pressure system pushes eastward into the
great lakes region with the front also pushing into Tennessee and
northern Georgia and Alabama this evening into the overnight. Over
our area SPC has outlined extreme northwest Georgia in a slight risk
(level 2 of 5) with a marginal risk (level 1 of 5)pushing southward
to the northern reaches of the metro. Taking a deeper dive into the
parameters, MUCAPE values of 2500-3000J/kg, 40-55kts of 0-1km bulk
shear and 0-1km SRH values of 200-300 m^2/s^2 are forecasted for
northwest Georgia as the line pushes into northwest Georgia. These
variables are conducive to the slight risk outlined with damaging
wind gusts and a low risk for tornadoes. The tornado risk has gone
from very low to low with this system with the main area to watch
for being that far NW GA area. Would not be surprised to see a few
spin up type tornadoes, but overall that damaging wind threat will be
the highest. Timing for the system looks like 1-2AM to push into far
NW Georgia before pushing southward and reaching the northern metro
by 4-5AM before the front loses steam and stalls out. The main
threat window will be from 1AM-8AM tomorrow.

After the front pushes into the area late morning, expecting it to
stall out over the area somewhere between the metro and a line from
MAcon to Columbus where tomorrow could see some showers begin to
form along the boundary. CAMs are a little less bullish on this and
thus precip chances are closer to 20-30%. Tomorrow night could see
the beginnings of another wave of precip moving into the area but
most of that timing is pushing into Sunday and thus mentioned below.

Hernandez

&&

.LONG TERM...
(Sunday morning through next Thursday)
Issued at 308 PM EDT Fri May 16 2025

Key Messages:

  - Rain and a few thunderstorms possible on Sunday. Can`t rule out
    an isolated severe storm or two.

  - Monitoring for storm potential in north Georgia on Monday. Again,
    can`t rule out the possibility of seeing something severe.

  - Stronger front will roll through in the middle of next week. Will
    need to monitor this for some severe weather potential, but
    currently a bit too much uncertainty around timing,
    orientation, and some other parameters to solidly say severe
    will be possible.

Forecast:

Stalled surface frontal boundary will still be in place across the
CWA Sunday morning as a quick hitting shortwave rotates through the
longer-wave ridging building over the CWA between two troughs
located over the eastern seaboard and western CONUS. This system
looks as though it will cause enough surface mass response to
generate some rain and possibly a few thunderstorms over the CWA
on Sunday morning into Sunday afternoon, with best chances to the
west/northwest where isentropic lift will be most aligned with the
stalled surface boundary. Model soundings are limited in
instability, especially given the potential for cloud cover, but
given the shear that will be in place, there will be the
possibility for an isolated severe thunderstorm to occur, with
damaging wind gusts being the primary threat. These should quickly
lose steam by sunset, though some showers and storms may linger
into the overnight hours.

Monday has started to get an interesting look to it from this
forecaster`s perspective. Another shortwave (in this case, noted as
a piece of the upper level PV within the western trough that gets
sheared off as a result of a stronger TPV digging in behind it)
ejects into the Great Plains Sunday evening and causes a pretty
robust baroclinic response with surface low and convection
developing. Diving into some of the deterministic output shows that
some of the guidance holds that convection together overnight as it
rides the subtropical ridge and becomes a bit organized with
potential cold pool. This convection then turns more south during
the day on Monday as it rides within the NW flow, become a pretty
classic setup for a honkin` line of storms to move through portions
of the southeast. This will need to be monitored going forward for
severe potential, given an ample parameter space will exist with
plenty of shear and instability. Uncertainty is still a bit too high
to highlight this as a severe area within SPC style outlooks,
however, both around if it forms and exactly where it would
eventually travel.

By the middle of the week, set up aloft gets a bit more complex. The
larger trough in the desert SW is progged to eject into the Great
Plains and eventually into the eastern CONUS, but several complex
interactions around this will dictate exactly where and when it ends
up traveling. These interactions will have strong dependencies on
convection (and more specifically, the latent heating produced by
said convection) that I simply do not trust longer range global
guidance to have a good handle on. Still, as some point the
expectation is that a stronger cold front will push through the CWA,
bringing an additional round of rainfall and the potential for some
form of severe weather (insert "It`s gonna be May" JT meme here).

Only other thing to note will be the temperatures. While highs on
Sunday may be a bit more muted thanks to the weak front and
potential cloud cover and rain, they are still forecast several
degrees above average in the mid 80s to low 90s. This only builds
into Monday and Tuesday. Current forecasts are a few degrees below
the record highs at several locations, so expect some heat.

Lusk

&&

.AVIATION...
(00Z TAFS)
Issued at 740 PM EDT Fri May 16 2025

A BKN VFR Deck is expected to remain in place into the overnight
hours. A line of TSRA is expected to reach ATL after 10Z and clear
out around 14Z. Winds will be on the west side at 5-10kts. After the
line clears the area, there could be a few hours of low CIGS on the
back side of the front, though obs below MVFR are not expected.


//ATL Confidence...00Z Update...

High on all elements.

Vaughn

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          70  87  66  86 /  10  30  10  30
Atlanta         71  87  68  87 /  30  20  10  40
Blairsville     64  81  61  80 /  60  20  10  40
Cartersville    68  87  65  86 /  50  20  10  50
Columbus        70  90  68  90 /   0  20  10  40
Gainesville     70  85  67  85 /  30  20  10  40
Macon           69  90  68  90 /   0  20  10  30
Rome            68  87  65  85 /  60  10  20  50
Peachtree City  70  87  65  87 /  20  30  10  40
Vidalia         69  92  71  92 /   0  10  10  20

&&

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

$$

SHORT TERM...Hernandez
LONG TERM....Lusk
AVIATION...Vaughn