Area Forecast Discussion
Issued by NWS Atlanta, GA

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FXUS62 KFFC 161622

Area Forecast Discussion
National Weather Service Peachtree City GA
1222 PM EDT Mon May 16 2022


A weak cold front is currently approaching northwest Georgia from
Tennessee/Alabama. As it moves through the forecast area today,
there is the potential for a few isolated showers and
thunderstorms to develop. CAMs this morning have trended a little
drier and are showing less organized storm development out ahead
of the front. While showers have not materialized this morning,
isolated showers/thunderstorm activity is still possible this
afternoon with SBCAPE over 1000 J/kg progged over much of the
forecast area. If enough destabilization occurs from daytime
heating and additional lift from the frontal passage produce
thunderstorms, the primary hazard will with storms will be gusty
winds. Have made a few adjustments to the grids this morning but
the forecast largely remains on track.

.PREV DISCUSSION... /Issued 441 AM EDT Mon May 16 2022/

SHORT TERM /Today through Tuesday/...

As the morning begins, the axis of a weak upper level trough remains
positioned over Georgia, which is keeping weak flow throughout most
of the atmospheric column. At the surface, persistent southerly flow
on the west side of the Bermuda High has continued to bring warm and
moist Gulf air into the area. Dewpoints are in the low to mid 60s
and precipitable water values have climbed to between 1.25 and 1.5
inches. A mid level trough is currently swinging through the
Midwest, and will lift towards the Mid-Atlantic over the course of
the day. Over this point, a mid level speed max will round the base
of this trough and the trough will gain a negative tilt. A low
pressure system is already developing to the immediate east of the
trough, near Ohio. With the negative tilt of the trough, the low
will quickly intensify as it moves northeastward. A cold front
extending from this low is already moving into the Tennessee Valley,
and will continue to advance towards north Georgia this morning as
it gets a push from surface high pressure over the Ozarks.

Scattered showers and thunderstorms will be loosely organized ahead
of the frontal boundary as it pushes into north Georgia during the
early afternoon and into central Georgia during the late afternoon
and evening. While it is possible to see a few showers this morning
in far north Georgia, most of the convection is not expected until
destabilization occurs due to diurnal heating. SBCAPE values of 1000-
1500 J/kg will aid in thunderstorm development in addition to the
lift from the front. Low level and deep layer bulk shear are
expected to be quite weak, which will limit the potential for long-
lived, organized severe weather. However, with precipitable water
values continuing to increase, it is still possible to see storms
with short-lived updrafts produce strong, potentially damaging wind
gusts and large hail due to precipitation loading in the downdrafts.
As a result, the SPC has diagnosed a Marginal Risk for strong to
severe thunderstorms across the majority of the forecast area.
Precipitation chances will come to an end from north to south as the
front moves through the area, exiting to the southeast by midnight.

After the weak frontal system clears the area, dry northwesterly
upper level flow will set up over the region. Surface high
pressure is also expected to develop over the Southeast on
Tuesday, where it will remain into the first parts of the long
term period. Subsidence of dry air aloft will lead to mostly clear
skies throughout the day on Tuesday. Temperatures underneath the
high and clear skies will be between 4-8 degrees above average,
ranging from the mid 80s in far north Georgia to the low 90s in
central Georgia. Dewpoints are expected to drop into the upper 40s
to low 50s across north and central Georgia during the daytime on
Tuesday. Considering the combination of high temperatures and
minimum dewpoints, relative humidity values will need to be
monitored. RH values could briefly reach critical fire danger
thresholds in portions of central Georgia, but at this time, it is
anticipated to only be for a couple of hours and not for long
enough to warrant a fire danger statement at this time.


LONG TERM /Tuesday Night through Sunday/...

The extended forecast starts off dry as a weak surface high
pressure ridge is expected to settle over the area. By Wednesday,
low level flow begins to turn southerly allowing some increased
moisture back to the region. There will be a slight chance of
showers and isolated thunderstorms Thursday afternoon for North
Georgia as a wave of moisture passes through the Tennessee River
Valley. This increased southerly flow will also usher in some
abnormally hot temperatures through the end of the week. The
combination of mostly dry conditions and weak high pressure will
help to suppress convective development and dense cloud cover
allowing temperatures to climb into the 90s across the forecast
area. Most locations will see temps about 10-15 degrees above
seasonal norms and will most likely see some record
highs...especially across central portions of the state.

By Saturday, the gradual exit of the surface high pressure and the
stronger southerly flow, should allow much deeper moisture return
across the state. This will increase precip chances for diurnal
showers and thunderstorms each day through the weekend.


12Z Update...
Aside from some patches of fog with 4-6 SM during the early
morning hours, VFR conditions are expected across north and
central Georgia through the period. A SCT cu field between 030-050
will develop after 15Z and persist through the afternoon hours.
SHRA/TSRA will be possible ahead of an advancing cold front in the
afternoon. Hi-res guidance continues to indicate scattered
coverage at best, and the existing TEMPO for TSRA has been
shortened to 19-21Z at ATL. Chances for precip are expected to
come to an end by 01-02Z. Light SW winds at 5 kts or less to
start the morning will shift to W at 8-10 kts by 15Z and 10-12 kts
with gusts as high as 22 kts after 18-19Z. Winds will then
diminish overnight, and could flirt with NE after sunrise on

//ATL Confidence...12Z Update...
Medium confidence on coverage and timing of SHRA/TSRA this
High confidence on all other elements.



Athens          58  87  59  91 /  10   0   0   0
Atlanta         61  87  62  92 /  10   0   0   0
Blairsville     52  81  54  85 /   5   0   0   5
Cartersville    56  86  58  92 /  10   0   0   5
Columbus        63  91  62  95 /  20   0   0   0
Gainesville     58  85  60  89 /  10   0   0   0
Macon           60  92  59  95 /  20   0   0   0
Rome            57  88  58  92 /   5   0   0   5
Peachtree City  58  87  59  92 /  10   0   0   0
Vidalia         68  91  64  95 /  30   5   0   0




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