Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 171127

Area Forecast Discussion
National Weather Service Peachtree City GA
727 AM EDT Sat Mar 17 2018

.PREV DISCUSSION... /Issued 433 AM EDT Sat Mar 17 2018/

SHORT TERM /Today through Sunday/...
To our north, a weakening closed low is pushing into the Ohio Valley
this morning. While this low will track north of our area today,
midlevel energy has begun to bring an increase in shower coverage
over Alabama and north Georgia. Coverage of showers should continue
to increase relatively quickly through the remainder of the morning,
initially across north Georgia and transitioning south and eastward
through midday into the afternoon. The potential for isolated
thunderstorms will begin to increase around sunrise and transition
into central Georgia by afternoon. Instability will increase into
the 1000 J/kg range this afternoon, but shear is unimpressive, and
no strong/severe thunderstorms are expected.

While rain chances will generally decrease from north to south
through the afternoon, the isolated shower and thunderstorm
potential will return across far north Georgia this evening as the
aforementioned dampening low traverses the Appalachians. Any
isolated convection will then gradually taper off through late
evening as the low exits east. The associated weak surface front
will push into central Georgia and stall. The remainder of Saturday
night into Sunday morning will be dry until the stalled front begins
to lift back northward as a warm front late Sunday. As this occurs,
shower and thunderstorm coverage will begin to quickly increase by
Sunday evening. This will lead into a much more active and stormier
period Sunday night into Monday.

Temperatures will remain above normal today through Sunday with
highs generally in the 70s and low temperatures Sunday morning
ranging from the upper 40s far north Georgia to the upper 50s to
near 60 in central Georgia.


LONG TERM /Sunday Night through Friday/...
A fairly aggressive system making its way into our area for the
beginning of the extended forecast. High pressure builds back
into the region for the middle to end of the 7 day forecast.

The cold front that moves through the area today moves back
northward as a warm front Sunday night with the next cold front
directly on its heels. Beginning Sunday night/Monday morning,
moist southwesterly flow sets up across the area as the warm
front moves into central portions of the state. Instability
indices increase across the state as a a strong piece of southern
stream energy interacts with the warm front. This will produce
periods of locally heavy rainfall and some isolated to scattered
thunderstorms. Currently, the axis of heaviest rainfall is progged
to be across central and south GA. Another bout of moderate to
locally heavy rainfall is possible Monday night into Tuesday as
the cold front moves through.

As far a s the possible severe weather from this system the
models are coming into a bit of better agreement as far as timing
and intensity. Instability peaks Sunday evening then weakens
Sunday night through early Monday morning. This should keep any
thunderstorms to a minimum but would not be surprised to see
strong thunderstorm during this time frame. The mid level lapse
rates stay fairly steep...and some surface instability will be
present so can not rule out a severe storm. Instabilities
increase during the day Monday with muCAPE increasing into the
800-1800j/kg range and shear and lapse rate values staying up as
well. There is not as much deep moisture present but with a
secondary cold front sweeping around the parent low and daytime
high temps in the 60s and 70s...the atmosphere will be primed for
severe storms to develop. SPC also agrees and has placed the
majority of the state under a slight risk for day 3 with NW and
west central GA under a 10 percent hatched area for significant
severe weather. Will be keeping a close eye on this over the next
few days

Behind the cold front, for the latter half of the week, colder than
normal temps will return. will most likely have to issues some
frost/freeze products Wed/Thu.



12Z Update...
Scattered showers and a few thunderstorms have begun to overspread
the area this morning. As rainfall coverage has increased, so have
MVFR ceilings. Best window for showers and isolated -tsra
activity will be through around 15z at ATL area sites with window
a bit later at MCN/CSG. Primarily MVFR ceilings this morning will
likely trend towards IFR ceilings by mid-morning as showers push
eastward. IFR ceilings should scatter and lift through the
afternoon and evening hours. There is some potential for at least
MVFR clouds to return by Sunday morning, especially at CSG/MCN.
Winds will remain on the west side through the period at 5-11kts.

//ATL Confidence...12Z Update...
Low to medium confidence on ceiling trends.
High confidence on other elements.



Athens          72  54  74  54 /  70  10   5  60
Atlanta         73  54  72  55 /  70  10  20  70
Blairsville     68  45  67  48 /  70  20  10  60
Cartersville    74  51  71  53 /  60  20  20  60
Columbus        77  58  76  60 /  60  20  40  70
Gainesville     70  52  71  52 /  70  20  10  60
Macon           75  57  77  58 /  60  10  20  70
Rome            74  50  71  53 /  50  20  20  60
Peachtree City  74  55  74  55 /  70  10  20  70
Vidalia         77  60  79  60 /  40  10  10  70




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