889
FXUS62 KFFC 151737
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
137 PM EDT Wed May 15 2024



...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Thursday)
Issued at 339 AM EDT Wed May 15 2024

Key Messages:

 - Scattered showers and isolated thunderstorms are expected this
   afternoon.

 - A warming trend will arrive Thursday as high temperatures
   return to the mid and upper 80s.

Today through Thursday:

The driving forces behind today`s weather will be an upper level
trough and surface low over the southern Appalachians. Westerly flow
around both features will bring westerly winds to the region today.
Gusts in the 20 to 25 mph range can be expected between noon and 6
PM today. Once the winds and diurnal heating kick in this morning,
the ongoing low clouds and patchy fog should dissipate. By this
afternoon diurnal heating should be sufficient to produce MLCAPE
values between 400 and 800 J/kg. This instability should help widely
scattered showers and isolated thunderstorms develop between noon
and 8 PM today. Given the modest instability and weak shear (~20
kt), severe weather isn`t expected. The best thunderstorms chances
should be over northern Georgia this afternoon where 700-500 mb
lapse rates will be highest (near 5.5 C/km). Smaller lapse rates and
narrow mid level CAPE profiles should make thunder harder to come by
in central Georgia. Any rainfall today is expected to be light,
brief and spotty in nature. Cloud cover should inhibit temperatures
today, especially in northern Georgia where highs in the 70s are
expected. More sunshine and a greater distance from the trough
should allow highs to reach the mid 80s from Macon southward.

Any lingering rain showers will dissipate quickly tonight with the
loss of diurnal heating. By Thursday, the upper level trough that
has been with us for a couple days will be replaced by a transient
upper level ridge. Subsidence from the ridge should bring fair skies
and dry weather to the region on Thursday. Temperatures should
respond accordingly by rising to 3 to 6 degrees above seasonal
averages. Expect afternoon highs in the upper 80s.

Albright

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 339 AM EDT Wed May 15 2024

Beginning of the long term forecast sees our next weather system
moving into the area. By Friday morning, several of the 00Z
convective allowing guidance show a reasonable scenario, in which
moisture is being lifted isentropically across the area ahead of the
upper level low moving out of the southern Great Plains. This will
likely be relatively light to moderate rain, though can`t rule out
some elevated convective elements. Going forward, have chosen to
"cap" our PoPs a bit here in the CWA Friday night and Saturday, as
beginning to think we may see similar evolution convectively to
the weather system moving through the area now. Most models,
including ensembles, show a pretty sharp theta-e gradient down
towards the coast, and the development of the surface low in
tangent with the moving upper level low isn`t anything too
special. This keeps the surface mass response modest and the
theta-e gradient further south. This would likely be reinforced by
any rain/T-storm development along and north of the gradient with
rain-cooled air. Some of the deterministic guidance shows the
potential for MCS development upstream that would likely stay
along said theta-e gradient, which would keep the heaviest
rainfall and thunderstorms out of the CWA (though some rain is
likely to still occur). That all said, if that doesn`t play out,
there is certainly the potential to see some decent rainfall out
of the system as plenty of moisture returns, with the higher
probabilities towards central GA which would have the best chance
of seeing an organized convective system. QPF amounts are in the
1-3" range at this time, but understand that the overall potential
spread is high dependent on how convection plays out...and this
forecaster will fully admit to not being good enough to tell you
those details 48-72 hours out.

The system looks to finally lumber its way out by Sunday. Some
precip chances linger as the upper level trough still could form a
surface low off the coast, but guidance has shifted that a bit to be
less impactful to our CWA. We should get a few days of clearing
thanks to shortwave ridging that builds into the area. Moisture
begins to return by Tuesday thanks to upper level system to the
north, and PoP chances will slowly increase as diurnal thunderstorms
become possibly (summer is almost upon us). Our next system may be
impacting us by mid next week, but that is well out into the realm
of uncertainty. Temperatures on days without rainfall should be
pretty seasonable, generally within 5 degrees of climatology.

Lusk

&&

.AVIATION...
(18Z TAFS)
Issued at 133 PM EDT Wed May 15 2024

Scattered showers should mainly stay north of I-20 but could
impact a few of the TAF sites this afternoon into evening. After
showers move out, skies should begin to clear ~23-00z and remain
there through the remainder of the TAF period. Winds currently are
from the W/NW with gusts up to 23-35kt but should start to die
down after sunset.

//ATL Confidence...18Z Update...
Low confidence on showers impacting the airfield.
High on all other elements.

Hernandez

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          61  86  62  81 /   0   0  10  50
Atlanta         61  86  65  81 /   0   0  10  60
Blairsville     57  79  57  75 /  20   0  20  70
Cartersville    58  84  61  80 /  10   0  20  60
Columbus        62  88  66  83 /   0   0  20  60
Gainesville     61  85  63  78 /   0   0  10  60
Macon           62  87  65  84 /  10   0  10  40
Rome            58  85  62  80 /   0   0  20  70
Peachtree City  60  86  63  81 /   0   0  20  60
Vidalia         66  88  67  87 /  10   0   0  30

&&

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

$$

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