916
FXUS62 KFFC 260147
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
847 PM EST Wed Dec 25 2024


.UPDATE...
Issued at 842 PM EST Wed Dec 25 2024

High pressure wedge has started to build down into NE GA this
evening. Mid and high level cloudiness will continue to increase
overnight. Low clouds will begin to push into SE GA overnight and
possibly make it as far north as the I-20 corridor. Forecast looks
good and have only tweaked the hourly dewpoints to reflect current
conditions.

&&

.SHORT TERM...
(This afternoon through Thursday)
Issued at 143 PM EST Wed Dec 25 2024

Key Message:

- Increasing cloud cover and wedge development.

Merry Christmas! Dry conditions through Thursday morning. High
pressure over the East Coast will continue to drive increasing
wedge development. Near-surface dry conditions have continued to
overpower mid-level moisture advection ahead of any shortwave
until larger scale upper-level features can make their way into
the Southeast. Timing-wise, increasing cloud cover will begin
Thursday late morning to late afternoon across the southern
counties and work northward. The current modeled wedge extends
beyond 850mb and meaning significant moistening or forcing will
need to occur before precipitation makes it to the surface. The
first bits of rain may occur more as drizzle south of Macon and
Columbus Thursday morning. The larger scale forcing won`t arrive
until that long term outlook, however more significant PoP
increases will approach from the northwest.

SM

&&

.LONG TERM...
(Friday morning through next Tuesday)
Issued at 143 PM EST Wed Dec 25 2024

The long term period picks up on Friday with the wedge firmly in
place across portions of north and central Georgia. Increasing
moisture advection and isentropic lift will support a 15% to 30%
chance for rain showers across portions of north Georgia. At the
mid-/upper-levels, a disturbance/speed max over the ArkLaMiss on
Friday will strengthen on Saturday as the larger-scale trough axis
shifts eastward over the Mississippi Valley. The SREF progs PWAT
at 1.0" to 1.3" on Saturday, which is around the 90th percentile
per sounding climatology. As such, expect increasing coverage of
showers on Saturday afternoon and evening.

The longwave trough axis will shift eastward across the Southeast
Saturday night through Sunday afternoon, bringing with it a cold
front. Mid-/upper-level dynamics and frontal convergence will
increase precip efficiency during this time and may support
locally heavy rainfall. On Sunday, temperatures and dew points
will surge into the lower 70s to mid-70s and lower 60s,
respectively. The National Blend of Models (NBM) depicts an
increasing likelihood -- greater than 50% -- for SBCAPE to exceed
500 J/kg across this warm sector (of sorts). Additionally, the
global ensembles suggest some 35-55 kts of bulk shear on Sunday,
so will need to continue to assess progged shear profiles
regarding the potential for storm organization (which would in
turn increase the heavy rainfall potential). The current storm
total QPF is widespread 0.5" to 1.5" (with the lower totals
across the southern portion of the forecast area). 2.0" to 3.0" of
rain may fall across the higher terrain of north Georgia. The WPC
has maintained a Marginal Risk for excessive rainfall on Saturday.

PoPs are forecast to drop off to near-zero on Monday as the
trough axis and moisture feed shift further east of the forecast
area. That said, there is currently a chance (30% to 50%) for rain
showers on Tuesday as a low pressure system slides across the
Ohio River Valley in response to a disturbance aloft and the left
exit region of a west-to-east oriented jet streak centered over
the southern tier of the CONUS.

Highs on Friday are forecast to range from the upper 40s across
northeast Georgia (within the wedge) to the upper 60s across our
southern counties. Temperatures will increase to well-above-
average through the weekend as return flow brings warm, moist air
across north and central Georgia.

Martin

&&

.AVIATION...
(00Z TAFS)
Issued at 624 PM EST Wed Dec 25 2024

VFR overnight with increasing high and mid clouds. Some sct MVFR
clouds possible towards 12Z tomorrow morning. MVFR deck will
likely go BKN after 00Z FRI. East winds through the period.

//ATL Confidence...00Z Update...
Med confidence cigs. Otherwise, high confidence all elements.
NListemaa

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          36  54  41  49 /   0   0  10  30
Atlanta         39  55  44  52 /   0   0  10  20
Blairsville     35  53  39  49 /   0   0  10  40
Cartersville    40  56  44  52 /   0   0  10  30
Columbus        40  60  47  63 /   0   0  10  10
Gainesville     38  53  42  47 /   0   0  10  30
Macon           38  57  45  60 /   0   0  10  10
Rome            38  57  44  53 /   0   0  10  30
Peachtree City  37  55  44  55 /   0   0  10  10
Vidalia         42  59  48  68 /   0  10  10  10

&&

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

$$

SHORT TERM...NListemaa
LONG TERM....Martin
AVIATION...NListemaa