Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 231945
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
245 PM EST Fri Feb 23 2018



.SHORT TERM /Tonight through Saturday Night/...

High pressure off the SE coast will continue to usher in moist
southerly flow through the period.  As a trough digs into central
CONUS, this will start to suppress the current ridge in place. This
will also supply higher PWats to the area early Saturday. Therefore,
we expect CU development to erode by the evening hours with some
mid/high level clouds moving into the region well ahead of the main
system to the west. A piece of energy riding between the incoming
trough and exiting ridge will aid in better precipitation coverage
across far north GA by early tomorrow morning. Some guidance is
suggesting we will saturate quickly across the area resulting in
scattered showers during the morning hours, expanding farther
south...although coverage looks quite minimal through the remainder
of tomorrow afternoon. The front associated with the trough will
slowly approach Sunday morning with a line of showers and embedded
thunderstorms expected to edge closer to the NW tier near sunrise
Sunday.  Given the lack of instability, only have a mention of
isolated thunder associated with the heavier shower activity.

Fog tomorrow morning may be possible yet again.  However, the
overall extent does not seem as widespread as compared to today. Still
thinking portions of east central up toward Athens will see some
reduced visibilities, but this should erode through mid-morning.
With the wind increasing from the south in the morning, there should
be a bit more mixing at the surface to avoid stagnant low level
moisture.

Temperatures will continue to be above normal through the period.

26

&&

.LONG TERM /Sunday through Friday/...

Main adjustment was to increase some categorical pops with
advancement of slow moving cold front Sunday and then have a
slightly less progressive (already slow) trend to decrease pops
from the NW later Monday. Still have a portion of the area in a
Marginal Risk for extreme NW late Saturday and then centered along
the I-85 corridor for Sunday. Thinking isolated threat cannot be
ruled out despite meager instability since deep layer shear is
supportive. Guidance has large discrepancies on when moisture
field pushes east of the area with midweek disturbances so did not
change this portion of the previous forecast. Otherwise minor
adjustments made per latest model blend. Previous discussion
follows...

Baker

PREV DISCUSSION... /Issued 315 AM EST Fri Feb 23 2018/

LONG TERM /Saturday Night through Thursday/...
A rather active wet pattern looks to be in store this long term
period with 2 rounds overall expected.

The first round will be increasing Saturday night and Sunday and
continuing Sunday night and diminishing Monday. This will be due
to a cold front moving into the area on Sunday with a moist SW flow
aloft associated. It is unclear if the front will stall across
the area as the European model is indicating, with a wave on the
front forecast to move across the area on Monday ending the rain
chances. Or, the front just moves slowly E and S as the GFS is
indicating. In the both cases, a moist SW upper flow is providing
deep moisture. Both models end the precip during the day on Monday.
There is some instability associated across the area and low level
wind shear across mainly n GA early on Sunday. A slight chance or a
chance of thunderstorms can be expected into Monday.

There looks to be a break in the rain chances Monday night and
Tuesday before the second round of wet weather begins.

The GFS and European models are rather consistent with deep
moisture returning with overrunning southerly flow kicking in
Tuesday night and for the most part, continuing Wednesday before
another cold front moves to the area on Thursday with some
thunderstorm chances Wednesday night and Thursday. Rain chances will
ending quickly either late Thursday or early Thursday night.

N GA will be the target for the greatest rainfall with both rounds
and conditions will be monitored for any flooding potential.
Severe storm potential for n GA is low but not zero during round 1
and will be monitored as well.

For the most part, temperatures will continue well above normal
this low term period.

BDL

CLIMATE...

Records for 02-23

               Max Temperature         Min Temperature
  Station      High        Low         High        Low
  -------  ----------  ----------  ----------  ----------
   KAHN      79 2012     34 1989     57 1922     18 1939
                1980
   KATL      79 1980     32 1901     62 1909     19 1939
   KCSG      83 1996     37 1989     67 1962     18 1963
   KMCN      81 1980     37 1901     66 1909     22 1963
                1909

Records for 02-24

               Max Temperature         Min Temperature
  Station      High        Low         High        Low
  -------  ----------  ----------  ----------  ----------
   KAHN      81 1930     37 1947     58 1944     19 1989
                                                    1967
                                                    1947
   KATL      77 1982     35 1907     64 1890     17 1989
                                                    1947
   KCSG      81 1930     38 1901     61 1979     21 1989
   KMCN      79 1985     36 1901     62 1961     18 1901
                1930

Records for 02-25

               Max Temperature         Min Temperature
  Station      High        Low         High        Low
  -------  ----------  ----------  ----------  ----------
   KAHN      80 1930     34 1974     59 1992      8 1967
                            1967
   KATL      78 1996     26 1894     62 1890      9 1967
   KCSG      82 1930     36 1967     65 2001     17 1967
   KMCN      82 1930     35 1914     62 1918     14 1967


&&

.AVIATION...
18Z Update...
Cigs and vsbys have finally come up to MVFR/VFR criteria this
early afternoon. This was after much of the region was socked in
by low level moisture. Expect lingering mid level stratus to erode
with shallow CU development through the remainder of the
afternoon. Winds will be out of the south between 4-7kts. The
low/mid level cigs will erode this evening with high clouds moving
in during the early portion of the overnight. As the surface high
offshore retreats farther east and better moisture feed moves into
the region, expect increasing cloud coverage and lowering decks.
Fog/stratus development looks possible again tomorrow, but mainly
across east central/northern GA. Coverage may be more limited due
to the increase southerly wind speed. Expect low-end VFR cloud
coverage through tomorrow afternoon.

//ATL Confidence...18Z Update...
Confidence Low to Medium on morning cigs/vsbys.
Confidence High on all other elements.

26

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          59  78  63  74 /  10  20  20  80
Atlanta         61  78  63  72 /  20  20  20  90
Blairsville     58  72  59  65 /  30  30  40  90
Cartersville    60  77  62  67 /  20  20  30  90
Columbus        61  80  65  74 /  30  10  20  70
Gainesville     59  74  61  69 /  20  20  20  80
Macon           60  81  62  77 /   5  20  20  60
Rome            61  78  62  67 /  20  20  60  90
Peachtree City  59  78  63  71 /  20  20  20  90
Vidalia         62  81  62  82 /   5  10  10  40

&&

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

$$

SHORT TERM...26
LONG TERM....BDL/Baker
AVIATION...26



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