661
FXUS62 KFFC 181749
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
149 PM EDT Tue Jun 18 2024

...New 18Z Aviation Discussion...

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

Highlights:

-Warm temperatures continue through the Short Term.

-An isolated shower cannot be ruled out over in NE GA and across
 south-central GA This afternoon and again Wed afternoon.

Current satellite loop shows mainly fair weather CU developing across
North and Central GA. Surface Bermuda ridge and Mid level Mid
Atlantic ridge combining to keep things mostly dry over the area
but we are in easterly Atlantic flow. Most locations will remain
dry through Tonight but some isolated showers and/or storms
cannot be ruled out with the easterly flow especially at the
highest elevations in the northeast (terrain induced) and across
far south-central Georgia. Any storms that develop could produce
gusty winds and locally heavy rainfall.

Temperatures are still 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...
(18Z TAFS)
Issued at 105 PM EDT Tue Jun 18 2024

VFR ceilings with no precipitation or restrictions to VSBYs
expected. Winds will stay out of the East with speeds fluctuations
throughout the day. Wind speeds will start in the 10-15kt range
with gust to 22kt. Will see these speeds diminish top 10kt 8kt or
less after sunset then pick back up again after 15z Wed.

//ATL Confidence...18Z Update...

Confidence high on all elements

01

&&

.PRELIMINARY POINT TEMPS/POPS...
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

&&

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

$$

SHORT TERM...07
LONG TERM....Albright
AVIATION...01