Area Forecast Discussion
Issued by NWS Atlanta, GA

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117
FXUS62 KFFC 272331
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
631 PM EST Fri Nov 27 2020



.UPDATE...
Stationary frontal boundary remains across the southern CWA this
evening. The front should begin to move north overnight as a warm
front. Regional radar shows an area of showers and a few
thunderstorms across central AL, moving east. This area of
rainfall will push east across the CWA overnight. Have tweaked the
pops a bit ahead of the precip. Have also tweaked the hourly
temps/dewpoints.

&&

.PREV DISCUSSION... /Issued 227 PM EST Fri Nov 27 2020/

SHORT TERM /Tonight through Saturday Night/...
No significant weather impacts expected in the short term period. Main
forecast concern is timing of onset of light rain associated with
positively tilted short wave currently over the Midwest states.
Stationary front associated with previous wave never really pushed
as far south as models indicated and currently lying just south of
CWA and extending WNW toward western AL. Low clouds already
sneaked back into Columbus when all recent guidance indicated
they should have been clear all afternoon. Will need to watch this
trend as PoPs and clouds may move in faster than forecast this
evening. 12Z EC and EC MOS also indicating higher PoPs for tonight
so may bump them up a bit more before finishing the shift. No
matter the timing still appears that rainfall will be fairly light
with total amounts under 0.10 inches in north GA and 0.25-0.50
inches in middle GA. Could see some embedded TSRA but no
strong/severe convection expected.

Next round of SHRA/TSRA won`t arrive until Sunday with clearing
skies from the north Saturday afternoon.

SNELSON

LONG TERM /Sunday through Friday/...
The beginning of the forecast period Sunday will be very active as a
closed upper low over the Southern Plains transitions into an open
wave as it becomes absorbed into the northern jet stream. As this
occurs, a surface low will deepen as it tracks from the Mississippi
Valley into the Tennessee Valley by Sunday evening. Widespread
rainfall will thus be on the increase from west to east during the
day Monday as isentropic lift initially increases as a warm front
lifts northward. While some elevated embedded thunderstorm activity
is possible through the day Sunday, the risk for any strong or
isolated severe thunderstorms will be along and south of the warm
front late Sunday evening into Sunday night. Even in these areas,
forecast instability appears rather marginal, though plenty of shear
will spread across the area. In this low CAPE/high shear
environment, the potential for an isolated damaging wind or tornado
threat is there, primarily in Middle Georgia Sunday night.
Otherwise, healthy rainfall totals can be expected with widespread 1-
2" totals from Sunday into Monday morning with locally higher
amounts.

By Monday morning, the strong surface cold front will sweep into the
area, rapidly ushering in much colder temperatures for Monday. The
dry slot behind the front will bring an initial quick end to the
rain. However, the next situation to monitor will be the potential
for any wraparound light wintry precipitation Monday evening into
Monday night in north Georgia. Rapid cold air advection will bring
850 mb temperatures into the -8 to -10 degree C range by Monday
evening, so any lingering light wraparound moisture would be in the
form of light snow. At this point, moisture appears quite limited as
the cold and drier air rushes in. However, some very light
accumulations likely under an inch are possible, primarily in the
high elevations of the north Georgia mountains before this narrow
window closes.

Tuesday morning will bring the coldest temperatures of the season so
far with a widespread hard freeze in north Georgia with low
temperatures in the mid-20s. Even central Georgia will experience
lows in the upper 20s to lower 30s. This will (finally) bring the
first official freeze of the season to the Atlanta and Columbus
climate sites. High temperatures Sunday will struggle to crack 40
degrees in north Georgia with mid-to-upper 40s in central Georgia.
Dry conditions will persist through Wednesday as high pressure
settles overhead with another hard freeze areawide Wednesday
morning. Confidence then remains low by the end of the forecast
period as the ECMWF indicates a second approaching strong low
pressure system by late Thursday into Friday while the GFS remains
weaker. At this point will indicate increasing low-end PoPs at the
tail end of the forecast.

RW


&&

.AVIATION...
00Z Update...
A period of MVFR cigs possible as an area of precipitation moves
across metro ATL overnight. IFR cigs briefly possible at CSG/MCN.
Light and variable winds expected for much of the overnight, but
should pick up out of the NW during the day tomorrow. A wind shift
back to the east is possible during the mid evening on Saturday.

//ATL Confidence...00Z Update...
Med confidence all elements.
NListemaa

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          52  67  48  59 /  40  20   5  90
Atlanta         53  66  49  57 /  40  20  10  90
Blairsville     46  62  42  54 /  30  10   0  90
Cartersville    50  66  45  59 /  40  20  10  90
Columbus        59  70  54  63 /  80  50  30 100
Gainesville     53  67  48  56 /  30  20   5  90
Macon           56  70  51  63 /  70  60  20  90
Rome            50  65  44  61 /  40  20  10  90
Peachtree City  53  67  48  60 /  50  30  20  90
Vidalia         58  67  55  67 /  60  70  10  70

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...NListemaa
LONG TERM....RW
AVIATION...NListemaa



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