815
FXUS62 KFFC 262353
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
753 PM EDT Fri Jul 26 2024

...New 00Z Aviation Discussion...

.SHORT TERM...
(This evening through Saturday)
Issued at 308 PM EDT Fri Jul 26 2024

The region continues to be sandwiched between a weak upper low to
the west and ridging to the east thus keeping the gravy train
alive through at least Saturday. Models pinching off an upper low
across the the East coast this weekend which in turn flattens out
the Atlantic ridge a little by Saturday. A weak surface ridge
tries to wedge in from the NE tonight and really only results in a
slight wind shift out of the NE, but the very moist/high PWAT
airmass won`t budge, thus we will be socked in with a warm and
humid short term much like this past week. Without any real focus,
shower and thunderstorm activity will be a bit more limited today
and Friday and guidance generally agrees with this notion despite
the very high PWAT atmosphere. Expect diurnal shower and storms
to be prevalent each day mainly after 2pm.

Friday AM looks to be another low cloud kind of start. Model
cross sections consistent in depicting a saturated column from the
surface up to 500mb so could be another repeat of this
morning...particularly for northern GA including the metro. Will
need to keep a close eye on fog formation overnight as well. Winds
look to go calm with dewpoint depressions of less than 2 deg
pretty much area wide should yield some fog..esp in areas which
receive some rain today or areas where the ground is still wet.

30

&&

.LONG TERM...
(Sunday morning through next Thursday)
Issued at 308 PM EDT Fri Jul 26 2024

Very little change to the forecast package this afternoon. Still
some questions around the ability of the CAD wedge to make it to
the CWA, as some guidance today is trying to wrap the dry air a
bit more around the surface and upper level low that cuts off over
the western Atlantic. See previous discussion below.

Lusk

Previous Discussion
(Saturday night through Thursday)
Issued at 431 AM EDT Fri Jul 26 2024

The extended period begins on Saturday night with a highly amplified
pattern. An upper level ridge will extend from the northern Gulf
towards the Great Lakes region while a closed low develops off the
Atlantic coast. Overnight, surface high pressure associated with the
ridge will set up over the Appalachians. As this occurs, a CAD wedge
is anticipated to build into far northeast Georgia. The influence of
the low to the east could furthermore enhance CAD-like feature. If
this setup comes together, it could bring relatively drier air to
portions of east Georgia on Sunday. Here, dewpoints would lower into
the upper 60s as opposed to the mid 70s. Precipitable water values
in east Georgia would also lower to between 1.5 to 1.8 inches,
compared to nearly 2 inches across the remainder of the forecast
area. Over the course of the day on Sunday, a shortwave trough will
swing northeastward through the Midwest, dampening the
aforementioned ridge. The shortwave will also provide forcing for
showers and thunderstorms, which will be enhanced by diurnal
instability. At this time, likely PoPs are being carried in much of
central and west Georgia by Sunday afternoon, with chance PoPs in
east Georgia where the drier air is anticipated.

On Monday, the shortwave disturbance will pass to the north of
Georgia, which will scour out any wedge feature over northeast
Georgia and return ample moisture and high dewpoints to the whole
forecast area. With deep atmospheric moisture combined with forcing
near the shortwave, PoPs are forecast to range from 60-80 percent
across the majority of the area on Monday afternoon, with the
highest chances across the far north. Areawide, diurnally driven
convection is expected to continue each day from Tuesday through the
end of the period. Rainfall totals will be dependent on storm
formation locations, but the heaviest rain capable of producing
flooding concerns will be most likely across north and west Georgia
through Monday. With a broad ridge setting up over the western CONUS
at this time, much of the Southeast will be underneath a
northwesterly flow regime on the "dirty" side of the ridge. This
regime could favor increased shear and chances for organized
thunderstorms, and will thus need to be monitored. Increased cloud
cover will keep high temperatures limited to the 80s on Sunday
through Tuesday. Large scale moisture levels are forecast to
gradually decrease starting Tuesday into mid-week. At this time,
more scattered cloud cover will allow high temperatures to return to
the low to mid 90s by the end of the period.

King

&&

.AVIATION...
(00Z TAFS)
Issued at 746 PM EDT Fri Jul 26 2024

Isolated shra/tsra persist across portions of Central GA this
evening including metro ATL. Activity should diminish within the
next hour or two. Given the late arrival and lack of much rainfall
today the opportunity for lower IFR cigs to develop overnight
(09-13z) is now much lower. Kept the mention of a SCT IFR deck
around 10z for most locations but will continue to monitor trends
over the next few hours. Winds, currently NNW, look to largely
become VRB overnight (<4kts) and shifting solidly to the NE by
12z. ISO/SCT shra/tsra on Saturday beginning as early as 19z.

//ATL Confidence...00Z Update...

Medium confidence on the occurrence of IFR cigs and
timing/occurrence of tsra on Saturday.

High confidence on remaining elements.

07

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          70  88  70  89 /  40  30  10  30
Atlanta         72  87  71  87 /  20  30  20  60
Blairsville     66  81  66  81 /  30  70  20  60
Cartersville    71  87  72  87 /  20  40  20  60
Columbus        74  92  75  90 /  10  50  30  70
Gainesville     71  85  70  85 /  30  40  10  40
Macon           72  91  73  90 /  20  30  20  50
Rome            71  88  72  87 /  20  40  20  70
Peachtree City  71  88  71  87 /  10  30  20  60
Vidalia         74  91  73  90 /  30  40  10  40

&&

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

$$

SHORT TERM...30
LONG TERM....Lusk
AVIATION...07