413
FXUS62 KFFC 180557
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
157 AM EDT Sat May 18 2024


...New 06Z Aviation Discussion...

.SHORT TERM...
(This afternoon through Saturday)
Issued at 255 PM EDT Fri May 17 2024

So far today, dense cloud cover and the stabilizing effect of
showers have precluded deep convection across the majority of the
CWA. The exception has been the southwest portion of the CWA, where a
west-to- east oriented line of convection has shifted eastward out
of south- central AL. WPC has introduced a Moderate Risk for
excessive rainfall and flash flooding across our far southwestern
counties, where moderate to heavy rainfall and elevated/embedded
thunderstorms have been occurring since mid- morning. While
instability is not particularly exceptional, PWAT has surged to 1.7+
inches and 925-850 mb frontal convergence is strong, so the
expectation is that this messy area of convection will persist into
the evening, and possibly become better organized. Thinking that the
potential for severe storms is marginal at best across our southern
couple rows of counties, as instability has not been able to nose
northward from the Gulf Coast much due to the cold pool produced by
the area of convection. In the event of a strong or marginally severe
storm across our southern tier this afternoon or evening, damaging
wind gusts would be the primary threat. Will likely have scattered
showers and possibly isolated thunderstorms persist overnight as the
moist, southwesterly flow persists.

On Saturday, a shortwave trough coupled with progged MUCAPE of 1500-
3000 J/kg will be more than enough lift/instability to fire off
scattered to widespread convection across much of the CWA during the
afternoon and evening. SPC has a Slight Risk along and south of a
line generally from Eatonton to Macon to Columbus, where 0-6 km bulk
shear around 40-80 kts coupled with mid-level lapse rates of 6.5-7.0
deg.C/km support the potential for damaging wind gusts and hail. A
Marginal Risk encompasses much of the remainder of the CWA as the
environment farther north is also supportive of scattered
thunderstorms with some strong convection likely. A possible caveat
to coverage and/or intensity of storms will be how quickly/how much
cloud cover clears out. Another possible caveat... Some of the CAMs
indicate a morning MCS tracking along the Gulf Coast with showers and
embedded storms across portions of central GA, which could impact
airmass recovery in the afternoon. Given the dynamic, unstable
environment, isolated to scattered showers and storms could persist
well after sunset into the overnight hours.

Martin

&&

.LONG TERM...
(Sunday morning through next Thursday)
Issued at 255 PM EDT Fri May 17 2024

Starting off the forecast period with Sunday morning the troughing
associated with this weekends system will begin to move eastward into
the Atlantic. For Sunday, the vorticity couplet will still be over
eastern Georgia as well as a weak moisture axis which will result in
showers still lingering over eastern GA. With this last piece of
energy in our area, this will give way to just enough energy to
produce the chance for thunderstorms over eastern Georgia through
Sunday night.

After Sunday, a long wave ridge sets up over almost the entire
eastern third of the CONUS. This along with the lack of moisture over
the area will lead to a drier time for most of Georgia beginning
Monday and lasting until Wednesday. The unfortunate piece to this is
that temperature will quickly rise with many area reaching close to
90 which goes in line with the CLimate Prediction Center`s 6-10 day
outlook showing above normal temperatures.

While this ridging is dominating our area, the low pressure system
to the west will track into the Great Lakes region, not particularly
affecting the ridging. This will give way for the potential for a
small burst of vorticity and moisture to move into Tennessee and
northern GA by Thursday which could ultimately result in some shower
activity for northern GA. Should this system have enough energy it
will pave the way for more of a distinctive troughing feature to move
eastward into Georgia and the southeast to push the riding to the
east. Models are remaining split on whether this will happen or not a
week from now, so will see what the models indicate in subsequent
runs. With any showers, the risk for thunderstorms remains over the
area simply due to day time heating.

Temps will stay in the upper 80s over much of the area unless the
troughing is able to make it down to this area but this actually is
only 4-6 degrees above normal for this time of year. Definitely
trending towards the warmer summer time conditions (bummer for this
cool weather fan).

Hernandez

&&

.AVIATION...
(06Z TAFS)
Issued at 144 AM EDT Sat May 18 2024

Ceilings are primarily MVFR across north and central Georgia, and
gradually lowering. Ceilings are forecast to lower to mainly IFR
in the next couple of hours, although a drop to LIFR is looking
less likely than the previous forecast. Scattered -SHRA is
spreading into west and central Georgia, and is expected to
increase in coverage and spread north during the early morning
hours. As a cold front advances towards north Georgia, it will
send a broken line of organized SHRA/TSRA into north Georgia,
which will work its way southward in the late afternoon and
evening. A PROB30 for TSRA has been maintained for the northern
TAF sites as a result. Winds will be S to SW at 5 kts through the
early morning hours, becoming SW at 5-8 kts by 13Z and through the
remainder of the day.


//ATL Confidence...06Z Update...
Medium confidence on all elements.

King

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          62  79  59  82 /  50  50  10  10
Atlanta         64  81  63  83 /  50  40  10  10
Blairsville     59  77  57  78 /  50  60  10  20
Cartersville    61  82  61  83 /  50  40  10  10
Columbus        65  84  65  85 /  40  40  10  10
Gainesville     63  79  61  81 /  50  60  10  10
Macon           65  82  62  83 /  40  50  10  10
Rome            62  83  61  85 /  50  30   0  10
Peachtree City  63  82  61  83 /  40  40  10  10
Vidalia         67  83  64  82 /  50  70  20  10

&&

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

$$

SHORT TERM...Martin
LONG TERM....Hernandez
AVIATION...King