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000
FXUS62 KFFC 251535
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
1135 AM EDT Tue Sep 25 2018


.UPDATE...

Very few changes made to the current forecast besides minor tweaks
to the pops and temperatures with continued cloud cover and showers
currently dissipating across northern GA. Over the past 24 hours,
the northwestern corner of GA has received a widespread 2 to 4+
inches of rain. Have likely pops in that area for this afternoon
as well so we will continue to monitor the area this afternoon.


Reaves

&&


.PREV DISCUSSION... /Issued 751 AM EDT Tue Sep 25 2018/

PREV DISCUSSION... /Issued 420 AM EDT Tue Sep 25 2018/

SHORT TERM /Today through Wednesday/...
Wet short term period persists as ample moisture remains over the
region. Wedge of high pressure has nosed down the Appalachians and
into north Georgia, which should boost cloud cover over the area
today. Enhanced moisture remains draped from the Arklatex region
through the Tennessee Valley and into the Mid-Atlantic States, and
will offer increased precip coverage through the period. Second
frontal boundary will approach the state Wednesday, further
enhancing precip coverage over north and northwest Georgia. As a
result, have gone categorical PoPs for portions of north Georgia
Wednesday afternoon. May need to bump these PoPs up a little for the
remainder of the area, but new ECMWF slows the progression of the
front into the state, and did not feel confident in pulling likely
pops into central Georgia just yet.

Through Wednesday evening, expect generally 1 to 1.5 inches over far
north Georgia, with a tight gradient dropping amounts to a half inch
or less in the metro Atlanta area. This area has recently been dry,
but received a decent amount of rain in the last 24 hours. Isolated
flash flooding may become an issue should this amount of rainfall
occur in a short period of time, but given the expectation for it to
be spread out over the next 36 hours, most areas should be able to
handle it with little incident.

Cloud cover and precip will keep temperatures from being as high as
they could be, but still anticipate mid to upper 80s for much of the
area, and near 90 in portions of central Georgia. By Wednesday
afternoon, far north Georgia may only end up in the upper 70s to
near 80. Have generally gone with a blend of guidance for
temperatures.

31

LONG TERM /Wednesday Night through Monday/...

By the start of the long term period, the frontal boundary will
be situated across far NW GA with a weak wave developing south of
this feature over portions of central GA. By the time we get to
Thu afternoon, deep layer moisture will continue well above normal
with near 2 inch precipitable water values. Instability will be
limited, especially north of the front but should see just enough
during the afternoon hours to warrant thunderstorm mention and
likely coverage of pops.

More agreement among long term models in showing front has no
intention of making it through the area and in fact lifts back to
the north slightly for Friday afternoon. High deep layer moisture
content continues but majority of shortwave energy will remain
north of the area. With instability even further limited for
Friday, will keep pops in the mid range scattered category for
now.

Some clearing noted for Sat over Central GA as front continues to
drift north but this likely will only allow for increased
afternoon instability. Sufficient moisture to go along with this
to keep mid range pops in place through Sat. Front more or less
washes out over the area now through early next week. With deep
layer moisture pivoting south and a loss of a focusing mechanism,
will scale back pops to low end chance range.

Deese

&&

.AVIATION...
12Z Update...
Light rain has largely moved north of the Atlanta-area TAF sites,
with VCSH still in the TAF through mid morning. Expect additional
precip to develop this afternoon, but have opted for a VCSH over a
prevailing -SHRA due to uncertainty in coverage and location after
17z. IFR/low MVFR morning cigs will slowly improve this morning,
with VFR by this afternoon. E winds through the day today will
shift to the SW Wednesday morning between 10-14Z. Speeds will stay
7-11kt through the day, then drop to 6kt or less overnight.

//ATL Confidence...12Z Update...
Medium on all elements.

31

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          86  69  87  69 /  30  30  50  60
Atlanta         85  72  85  70 /  40  40  60  60
Blairsville     78  65  78  64 /  40  60  80  60
Cartersville    85  70  83  67 /  60  60  80  70
Columbus        89  73  89  72 /  40  30  60  50
Gainesville     82  70  83  68 /  40  50  70  70
Macon           90  71  91  71 /  20  20  40  50
Rome            86  70  82  67 /  60  60  80  70
Peachtree City  86  70  85  69 /  40  40  60  60
Vidalia         91  72  91  73 /  20  10  40  50

&&

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

$$

SHORT TERM...31
LONG TERM....Deese
AVIATION...31