726
FXUS62 KFFC 151739
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
139 PM EDT Tue Jul 15 2025

...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Wednesday)
Issued at 340 AM EDT Tue Jul 15 2025

Key Messages:

  - Return of more consistent diurnal thunderstorms with modest
tropical development.

  - Heat index values over 100 across the CWA this afternoon with
some potentially reaching as high as 108.

The sfc low from the weak tropical system currently sits roughly
over the Florida peninsula. Onshore flow from the Atlantic will
be the main driver of weather today, particularly along an axis of
weak convergence over the I85 corridor. Ample moisture will send
dewpoints into the mid to upper 70s (at least in east central
Georgia). Thunderstorms likely to start by the early afternoon.
CAPE values will be between 2000 and 3000 J/Kg, however given the
moist profiles not anticipating too much in the way of strong
outflow development. The main concern with these storms will be
the slow to near stationary movement along the convergence axis
and rainfall rates over 2" per hour. Localized PWATs could be
well above the 90th percentile and this afternoon`s balloon launch
could have an impressive PWAT value.

Temperatures today will be a big question mark, as they will heavily
rely on cloud cover and convection timing. The area of most concern
is the southeast and eastern portion of the CWA where cloud coverage
and PoPs are lower. In fact, scattered high clouds may increase
daytime heating by the afternoon. Given the uncertainty in the heat,
a heat advisory has not been issued yet for this afternoon. Would
not be surprised is some isolated areas saw brief period of heat
indices between 105 and 108. The first tell of the afternoons
outcome will be with cloud cover this morning. More cloud cover will
mean cooler temps.

Moving into Tuesday night/Wednesday morning, a few showers and
thunderstorms may continue along the convergence zone. Things should
taper off later into the night though.

Wednesday sees a return to diurnally driven scattered convection as
the ridge weakens from the sfc low to the south.  Heat Indices will
remain elevated and will likely need to keep an eye on the need for
heat advisories through the week.

SM

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 340 AM EDT Tue Jul 15 2025

Key Messages:

  - Scattered thunderstorms through much of the long term and into
the weekend.

  - Monitoring the weekend heat. Models creeping up in temperature
to the mid to upper 90s in many places, which will bring heat
indices well into the triple digits.

Forecast:

Pretty good agreement among the ensembles (and even the AIFS
ensemble) through much of the long term period over the CWA. Models
have come into pretty good alignment with the tropical disturbance
that will be moving across Florida into the Gulf today. By Wednesday
night into Thursday, most guidance has this feature near or along
the MS River Delta and slowly moves it onshore during the day as it
continues to slide underneath the dirty ridge in place over the
area. This system represents a decent slug of moisture regardless of
whether or not it develops into anything, and that moisture gets
stuck and strung out a bit with a system passing by well to the
north across the Midwest and Northeast Thursday night into Friday.
Upper level subtropical ridge looks to remain in place through the
weekend, and with copious moisture around, it looks like we can
expect some diurnally driven rain and thunderstorms. The details of
this, especially with regards to how the moisture gets distributed
across the southeast, how well the tropical system develops or
continues to spin across LA/MS/AR, and impacts of previous days
coverage of storms, will be challenging to nail down this far out,
so expect some fluctuation`s in the coming days with regard to
PoP chances. That said, generally expect diurnally driven PoPs of
at least an isolated nature through each day through the weekend.

Little in the way of shear in place means few concerns for severe,
but as I love to say during the summer, I`ll never rule out a storm
getting a bit spicy. Lapse rates won`t be anything special,
especially given things may be well close to moist adiabatic in some
places, but with plenty of surface heating and copious moisture,
instability will still be found and storms will still come down hard
on occasion.

One down side is that the increased confidence in the location of
the tropical disturbance seems to be driving warmer temperatures
within much of the guidance going into the weekend. Forecast highs
get well into the mid to upper 90s everywhere from the Atlanta metro
to the south and east. Dewpoints remain well into the low to mid 70s
even during the afternoon. Put together, heat indices and WBGT
values are looking to be pretty high, and current forecast heat
indices would be within heat advisory criteria. Will need to
continue to monitor things going forward, but either way, expect the
weekend to be sultry if you plan on being outdoors.

Lusk

&&

.AVIATION...
(18Z TAFS)
Issued at 132 PM EDT Tue Jul 15 2025

Cu field ~5kft is currently out there with thunderstorms expected
to begin ~21z and last through 01z. Could see showers pop up as
early as 20z and last until 03z. Tomorrow morning could see IFR
conditions that will lift to VFR by mid day. Winds should remain
out of the east through the period with light winds.


//ATL Confidence...18Z Update...
Medium confidence on IFR and TSRA timing.

Hernandez

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          94  72  91  73 /  40  40  30  20
Atlanta         95  75  91  75 /  40  40  20  20
Blairsville     88  67  86  68 /  60  40  30  40
Cartersville    96  74  94  73 /  30  30  20  20
Columbus        97  75  92  74 /  40  40  40  10
Gainesville     93  72  89  74 /  50  40  30  30
Macon           94  73  92  73 /  40  20  40  10
Rome            96  73  94  73 /  30  20  10  20
Peachtree City  96  72  91  72 /  40  40  20  10
Vidalia         93  75  93  75 /  40  10  30  10

&&

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

$$

SHORT TERM...SM
LONG TERM....Lusk
AVIATION...Hernandez