527
FXUS62 KFFC 241744
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
144 PM EDT Fri May 24 2024



...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Saturday)
Issued at 411 AM EDT Fri May 24 2024

The forecast for the next few days will be mostly dominated by
uncertainty around convective evolution upstream and over the CWA.
Convective models are - unsurprisingly - all over the place in terms
where and when storms may occur today, with even hourly runs of the
HRRR showing different solutions. But more important is that in the
ensemble sense, most all do allow for convective development, even
if scattered in nature.

Mostly zonal, but somewhat diffluent flow will be in place across
the CWA today. A large upper level system with attendant sfc low
is pulling to the north across the upper Great Plains, allowing
for moisture return across the southeast, though better return
will be further to the west. Plenty of moisture is in place with
PWATs exceeding 1.5 across much of the CWA. Importantly, forecast
soundings show that moisture to be distributed through the column,
which makes for less impressive lapse rates. This isn`t
surprising given multiple rounds of convection to our west over
the past day or two injecting and advecting moisture over the
area. Several embedded MCV or mesoscale vortmax features will move
into north GA today from that previous convection as well, and
could provide a focus for convective development. Higher PoPs are
concentrated to the north as a result. Provided we can clear some
of the convective debris aloft, ample sunshine will allow for us
to reach convective temperature at the surface by the afternoon
across the CWA, providing another way for storms to fire
elsewhere. Looking at the parameter space, models show thin MLCAPE
generally from 750-1500 J/kg across the area by the afternoon,
with effective bulk shear of 20-30 kts. Hodographs are relatively
straight given SW winds at the surface, so little in the way of
streamwise vorticity ingestion is available. Put it all together,
and you have a low end risk for some hail or straight line wind
damage today, hence the Marginal Risk (level 1 of 5) from the SPC.

Storm chances may continue a bit into the evening as plenty of
moisture remains and outflow boundaries could provide for a source
of lift. Going into the morning and afternoon of Saturday, a lot is
going to depend on convective evolution of today once again - both
here in GA as well as upstream. We will once again warm up enough to
allow for some afternoon thunderstorms, but the 06Z HRRR has
provided for an alternative solution, with a decaying MCS moving
into the area during the morning hours and leaving a nice cold pool
behind that limits any afternoon development. Given that forcing for
storms remains solidly in the realm of the mesoscale, have left a
general slight chance to chance PoPs across the CWA.

Lusk

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 411 AM EDT Fri May 24 2024

Afternoon and evening showers and thunderstorms expected through the
beginning of next week.

Nearly zonal Mid to upper level flow will allow several strong
shortwaves and a frontal boundary to move across the area through
Tuesday (Day 5). The forecast models are in fairly good agreement
with a few waves moving across the area Sunday and Monday with a
weakening frontal boundary moving through Tuesday.

These waves will mainly move through the state each afternoon
during the prime heating of the day with the potential to initiate
and sustain convection across North and Central GA. High temps will
be in the upper 80s to mid 90s Sunday through Tuesday. The models do
differ a bit on the timing of these waves but with this being a
fairly classic summertime pattern going with 30% to 60% each
afternoon should be enough for this sequence. A drier airmass is
expected to move in to the region Wed behind the exiting frontal
boundary. Surface high pressure builds Southeastward from the
Western great lake states with slightly cooler temps expected
days 6-7.

01

&&

.AVIATION...
(18Z TAFS)
Issued at 130 PM EDT Fri May 24 2024

Largely VFR conditions are anticipated through the TAF period. Sct
cu in the 4-6 kft range will characterize the afternoons. Patchy
MVFR cigs are possible 13-16Z Saturday, though widespread are not
expected. Sct SHRA/TSRA are favored, mainly at ATL area and AHN
sites, through this evening. While coverage is generally expected
to lessen overnight, iso SHRA/TSRA can`t be ruled out overnight.
Scattered SHRA/TSRA is more favored again by Saturday, especially
after 16-18Z. Winds outside of convection will remain W to SW at
3-7 kts.

//ATL Confidence...18Z Update...
Medium confidence on SHRA/TSRA timing and morning cigs.
High confidence on winds.

RW

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          66  89  66  91 /  30  30  20  30
Atlanta         69  89  69  91 /  30  40  30  20
Blairsville     61  83  61  83 /  50  40  30  40
Cartersville    64  88  66  90 /  40  40  30  30
Columbus        71  89  70  92 /  20  30  20  10
Gainesville     66  87  67  88 /  40  30  20  30
Macon           69  90  69  92 /  20  30  10  20
Rome            65  88  67  91 /  50  50  30  30
Peachtree City  66  89  68  91 /  30  30  20  20
Vidalia         71  92  72  94 /  20  30  20  20

&&

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

$$

SHORT TERM...Lusk
LONG TERM....01
AVIATION...RW