450
FXUS62 KFFC 131755
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
155 PM EDT Mon May 13 2024



...New 18Z Aviation Discussion...

.SHORT TERM...
(Today through Tuesday)
Issued at 358 AM EDT Mon May 13 2024

Key Messages:

 - The slight risk for severe weather today has shifted southward
   and out of central Georgia.

 - High temperatures should be 8 to 12 degrees below seasonal
   averages today.

 - Isolated severe storms may occur in the region Tuesday
   afternoon and evening.

Today and Tonight:

An upper level trough will track gradually from the Central Plains
towards the Tennessee Valley during this period. Lift ahead of the
trough should help generate widespread precipitation in the
Southeast over the next 36 hours. Guidance from the HREF favors the
development of two MCSs in the vicinity of a baroclinic zone along
the Gulf Coast. Forecaster confidence regarding the timing and track
of both MCSs has increased over the last 12 hours and we now expect
the most robust thunderstorm activity to be focused over southern
Georgia and the Florida Panhandle. Any storms that do occur in
central or northern Georgia should be elevated and this will hinder
the potential for severe weather. As such the Slight Risk (level 2
of 5) of severe weather that was over parts of central Georgia in
the prior SPC outlook has been shifted southward and out of central
Georgia in the latest update. A Marginal risk remains, but any
severe risk should be very limited. Forecast rainfall totals through
tonight have also been reduced due to the decreased convective
potential, and we now expect amounts in the 0.20 to 0.90 inch range
through 8 AM Tuesday.

Cloud cover and scattered rain showers should keep temperatures cool
today. High temperatures this afternoon are forecast to be 8 to 12
degrees below seasonal averages. This translates into temperatures
in the upper 60s and lower 70s.

Tuesday:

A weak shortwave trough should rotate around the parent trough in
the Tennessee Valley Tuesday morning. This should lead to a relative
peak in rainfall coverage in Georgia Tuesday morning. Clearing skies
behind the shortwave and diurnal heating should result in the
development of scattered thunderstorms Tuesday afternoon. Though mid-
level lapse range appear modest (5.5-6.0 C/km), increasing
instability (SBCAPE 1000-2000 J/kg) and 0-6 km shear values between
20 and 35 kt could generate a couple of strong or severe
thunderstorms. The main hazards with any storms are expected to be
damaging winds or hail. The storm prediction center currently has
all of Georgia painted with a Marginal Risk (level 1 of 5) for
severe weather. Forecaster confidence in isolated severe weather in
northern and central Georgia is higher for Tuesday than it is for
today.

Albright

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 358 AM EDT Mon May 13 2024

We pick up the long term forecast at the end of Tuesday, where some
interesting weather may still be ongoing across the CWA. For more
details on that, read above. Upper low aloft should be exiting
through the night with some lingering storms and showers that should
become more isolated as the night progresses. A broad sfc low
pressure will be in the process of transitioning across the
Appalachians on Wednesday to a new baroclinic zone with the Gulf
Stream, so low level moisture will be wrapping into parts of north
GA. This will bring some chances of showers, and if the sun breaks
out, possibly a storm or two. There also may be some remnant
boundaries in place near central Georgia that could be a focus for
an isolated storm or 2, especially in the east where the upper level
environment would be slightly less hostile.

Thursday continues to look mostly clear with highs quickly soaring
into the 80s across the CWA. Our next shortwave will arrive along
the southern branch of the jet stream on Friday as another wave is
passing by in the northern branch over the Great Lakes. Ensembles
differ in how these two interact, with some members phasing them a
bit, and others leaving the southern shortwave trailing a bit. In
terms of the forecast, our SW flow aloft with decent moisture return
in basically all solutions brings chances of rain - the question
will be just how much and will there be any severe component with
it. It will also have big impacts on the weekend forecast, as a wave
that lags behind will leave the CWA in a favorable regime for
continued diurnally driven precip chances, and another decent shot
of rain once the system finally pulls through, but the other
solution may leave a boundary near the CWA that could remain a focus
for showers and convection through the weekend. As a result, PoPs on
Friday are in the likely range, while the rest of the weekend shows
chance to slight chance to represent both the uncertainty and the
diurnally driven potential. Current forecast rainfall amounts would
be 1-1.5" across the CWA, but expect this to change as details
become more clear.

Lusk

&&

.AVIATION...
(18Z TAFS)
Issued at 147 PM EDT Mon May 13 2024

Ceilings are mainly VFR with precip ending across the ATL/AHN
area TAF sites. Will continue to see precipitation across CSG/MCN
for a few more hours. expecting MVFR and IFR ceilings to move in
after sunset and stay across the area through early Tue afternoon.
Will also see some light showers/drizzle overnight through Tue
morning ahead of the next round of precip moving back in across
the state Tue Afternoon. VSBYs are also in the VFR range but will
fall into the MVFR range over night with the lowered ceilings.
They should comeback into the VFR range as the ceilings lift Tue.
Winds are out of the East right now and will turn to the SE this
evening then to the SW just after daybreak Tue. Wind speeds will
stay in the 6-12kt range.

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

Confidence medium to high on all elements.

01

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          61  76  62  81 /  80  90  70  30
Atlanta         62  77  63  80 /  60  90  70  30
Blairsville     56  70  57  73 /  70  80  80  70
Cartersville    61  77  61  79 /  50  90  70  40
Columbus        65  80  66  83 /  60 100  50  10
Gainesville     61  73  63  78 /  70  90  70  50
Macon           64  79  65  83 /  60  90  50  10
Rome            62  77  61  80 /  40  90  70  40
Peachtree City  62  78  63  81 /  50  90  60  20
Vidalia         66  81  69  86 /  70  90  60  20

&&

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

$$

SHORT TERM...Albright
LONG TERM....Lusk
AVIATION...01