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Area forecast discussion...updated
National Weather Service Peachtree City Georgia
945 PM EST sun Dec 4 2016

Update...
no changes planned for the forecast. Periods of rain or drizzle
continuing. Temperatures near steady.

41

Previous...
short term /tonight through Monday night/...
short range models continue to show a wet pattern as a series of
disturbances embedded within the southwest flow aloft continue to
overrun a cool easterly flow near the surface to produce periods of
light to moderate rain. May see a short break in the rainfall early
on Monday as an upper low deepens over SW Texas which results in slight
ridging aloft here... but areas of rain should spread back into the
area by Monday afternoon/evening as the upper low begins to kick
eastward. Still thinking The Wedge of cool/stable air will greatly
hinder any thunderstorm threat through this short term... but will
have to monitor the far southern reaches Monday night for this
potential as The Wedge front begins to retreat northward and a
warm/moist unstable airmass begins to creep into areas generally
along and south of a Columbus to Vidalia line by early Tuesday
morning. Otherwise... will continue to word for just rain/rain
showers for now... along with some patchy fog and drizzle tonight as
clouds lower to near the surface.

Latest wpc and model guidances are suggesting the heaviest rainfall
axis will set up south of the I-85 corridor where rainfall amounts
of 1 to 3 inches are possible over the next 36 to 48 hours. These
amounts over this area should not be enough to cause any significant
flood concerns at this time... but if the heaviest rainfall axis
shifts northward... cannot rule out some brief minor flooding along
any of the typical flood prone creeks in the Atlanta area. Will have
to monitor this potential closely over the next couple of days.

The clouds and cool rain will continue to hold area temps in the 40s
overnight... but the break in the rain on Monday may be sufficient
to allow area temps to creep into the 50s Monday afternoon. If this
happens... clouds will likely hold area temps in the upper 40s to
lower 50s for lows Monday night. MOS pop and temp guidances were
close and looked reasonable... so did not stray far.



39

Long term /Tuesday through Sunday/...
mainly only tweaks to the long term based on the latest guidance.
Most precip chances will be ending late Tuesday into the evening.

Previous discussion...
once again, no significant changes to the general long-term forecast
trends. Medium-range models continue to show consistency with
previous trends and fairly good agreement amongst each other, at
least through mid-week. Although we are still seeing the models
generate some instability late Monday night and Tuesday, mainly
across the south still, the numbers are not impressive and low-
level shear is near negligible. I have kept the slight chance for
thunder in across western and southern areas Monday night and
across the south Tuesday, but prospects for any severe weather
remain low.

Models diverge a bit concerning the evolution of the the remainder of
the extended forecast period. Both bring in the coldest air of the
season so far behind the system later in the workweek, but there are
noticeable differences in timing of the cold air as well as the
precipitation chances ahead of the cold surge. My late week grids are
basically a compromise between the two for now.

20

&&

Aviation...
00z update...
LIFR ceilings in -radz should prevail until late Monday morning.
Expect some ceiling improvement to at least IFR levels Monday
afternoon as a break in the rain is expected. Visibility varying
from LIFR/IFR. Rain spreads back in by late Mon afternoon...and
this may lower ceilings back down to LIFR by Mon evening. Winds will
remain easterly 6 to 8kt with a few gusts possible.

//Atl confidence...00z update...
medium on timing of any improvement into IFR Monday.
High on remaining elements.

41

&&

Preliminary point temps/pops...
Athens 43 55 49 60 / 90 70 100 100
Atlanta 45 56 52 63 / 80 90 100 90
Blairsville 41 57 46 55 / 80 80 100 90
Cartersville 45 55 51 62 / 80 90 100 90
Columbus 51 60 58 70 / 80 100 100 70
Gainesville 42 55 48 58 / 90 80 100 90
Macon 49 60 56 73 / 80 90 100 100
Rome 44 55 51 62 / 70 90 100 70
Peachtree City 45 57 52 66 / 90 90 100 90
Vidalia 57 64 61 76 / 70 80 100 90

&&

Ffc watches/warnings/advisories...
none.
&&

$$

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