-- Discussion containing changed information from previous version are highlighted. --
772
FXUS62 KFFC 181041
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
641 AM EDT Tue Jun 18 2024

...New 12Z Aviation Discussion...

.SHORT TERM...
(Today through Wednesday)
Issued at 258 AM EDT Tue Jun 18 2024

Highlights:

-Warm temperatures continue through Wednesday.

-An isolated shower cannot be ruled out in south-central GA today
and Wednesday. Otherwise, mostly dry conditions expected.

Mid- and high level clouds blanket portions of the forecast area
early this morning. Winds remain light and temperature readings are
in the 70s. Midlevel ridging has shifted slightly eastward though
remains parked across much of the eastern CONUS with high pressure
just off the East coast. In addition to midlevel cu and high cirrus,
easterly winds will pick up late morning as mixing begins to occur.
Today most locations will remain dry, though some isolated showers
and/or storms cannot be ruled out at the highest elevations in the
northeast (terrain induced) and across far south-central Georgia.
Any storms that develop could produce gusty winds (inverted V-
Sounding) and locally heavy rainfall.

Temperatures both today and on Wednesday are forecast to be slightly
`cooler` than previous days with forecast highs in the upper 80s to
low 90s (80s in the mountains). Forecast lows will be in the upper
60s to low 70s. Lower dewpoints and afternoon RH values will keep
heat indices near the actual temperature. Nevertheless, continue to
be proactive if outdoors!

07

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 258 AM EDT Tue Jun 18 2024

Key Messages:

 - A gradual rise in temperatures is expected between Thursday and
Monday, with heat index values between 100 and 105 degrees possible
by early next week.

- Generally dry weather is forecast through Saturday, then
thunderstorm activity may pick up in the region during the first
half of next week.

Thursday:

No tangible changes have been made to the forecast for Thursday.
Guidance still favors a strong (598 dm at 500 mb) ridge over the Mid-
Atlantic. Though recent model runs have sought to extend the core of
the ridge further to the west (through the central Appalachians and
into TN & KY). Across Georgia this shift in the ridge suggests a
greater eastelry component to our winds aloft, but it doesn`t
portend any significant changes to the temperature or precipitation
forecast. Low PW values and limited instability should still result
in dry weather across central and northern Georgia, and high
temperatures in the 88 to 93 degree range are anticipated.

Pattern shifts between Friday and Early Next Week:

Trends in the GEFS and EPS guidance continue to favor a weakening
trend and westward shift in upper level ridge during this period as
a trough moves through the Great Lakes and eastern Canada. This may
bring some gradual cooling to the Northeast, though it will have
minimal impacts for the Southeast. Our temperatures in Georgia may
actually rise due to projected increases in temperatures in the
lower half of the atmosphere (850 mb temps rising to 2-4 C above
average). Our forecast highs from Friday through Tuesday remain
close to the NBM mean, suggesting highs in the upper 90s for most of
the region over the weekend. Some areas could see highs break the
tipple digit barrier. NBM guidance gives Atlanta a 14% chance to
reach 100 degrees on Sunday, while Macon has a 27% chance of
reaching the same threshold. For now the forecast keeps the regions
heat index values below 105 degrees (the threshold for a Heat
Advisory). A small change of only 1-3 degrees in the forecast
dewpoints or temperatures could push heat indices above 105
(especially on Sunday or Monday), and thus there is a non zero
chance of a Heat Advisory for portions of the state this weekend or
early next week.

Another feature to watch over the weekend will be an easterly wave
tracking through the Western Atlantic (near the Bahamas). The
National Hurricane Center has maintained a 20% chance (a slight
downward shift from 30%) for this feature to develop into a tropical
system with their latest outlook. Though this is a slight decrease,
it doesn`t change the overall message, and this is still a feature
that that will need to be monitored for potential impacts in
Georgia. A look at the ensemble guidance does suggest one
interesting forecast trend with this feature over the last 24 hours.
In general, the GEFS and EPS members have shifted towards a slower
and more eastelry track, which slightly slows the return of higher
PW values to Georgia. Both ensembles means are 12-24 hours slower
with PW values reaching 1.5 inches across the state. This shift
appears to be largely due to slightly stronger ridging to our west
impeding the westward progress of the eastelry wave. From a forecast
stand point it suggests a slight delay in the return of scattered
shower and thunderstorms chances to the state. Thus our forecast
rain chances have fallen below 15% for most of north Georgia on
Saturday, though 15-30% chances remain for Central Georgia. All
things considered tough, forecast confidence remains high that we
will shift towards a pattern more favorable for isolated to
scattered thunderstorms early next week.

Albright

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 639 AM EDT Tue Jun 18 2024

VFR conditions with no impacts expected through the period.
SCT-BKN 3-4kft cigs remain to the north of the northern terminals
this morning and not expected to move into these sites. Elected to
include FEW-SCT 4-5kft cigs for a few hours this morning. ESE/SE
winds will pick up to 8-13kts with gusts ranging 18-22kts as early
as 16z persisting until 00z. Any iso shra/tsra expected to remain to
the southeast of all terminals.

//ATL Confidence...12Z Update...

Medium confidence on lower cigs moving into ATL this morning.
High confidence on all elements.

07
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Athens          67  87  67  89 /   0   0   0   0
Atlanta         71  89  70  90 /   0   0   0   0
Blairsville     63  82  62  85 /   0   0   0   0
Cartersville    70  89  68  91 /   0   0   0   0
Columbus        73  90  70  92 /   0   0   0   0
Gainesville     68  86  68  87 /   0   0   0   0
Macon           69  90  68  91 /   0   0   0   0
Rome            71  89  69  92 /   0   0   0   0
Peachtree City  69  89  68  91 /   0   0   0   0
Vidalia         71  90  69  91 /  10  20  10  10
-- End Changed Discussion --

&&

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

$$

SHORT TERM...07
LONG TERM....Albright
AVIATION...07