-- Discussion containing changed information from previous version are highlighted. --
920
FXUS62 KCAE 230547
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
147 AM EDT Mon Sep 23 2024

.SYNOPSIS...
High pressure building over the SE US will keep warm conditions
over the Southeast into the first half of the work week.
Multiple shortwaves crossing the region will bring chances for
precipitation through much of the week. Confidence is low in the
forecast beyond midweek as uncertainty remains high with the
evolution of an upper trough moving toward the region and the
potential for tropical development in the Gulf.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
Key Message(s):

- Increasing clouds overnight and above normal temperatures

A couple showers which developed late this afternoon into this
evening continue across the southern Midlands and CSRA and will
gradually dissipate over the next couple of hours. Overnight
cloud cover will slowly increase especially across the northern
Midlands and Pee Dee however expect the remainder of the
overnight to be rain free. Lows tonight will remain on the
milder side with most locations in the upper 60s to around 70.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH TUESDAY NIGHT/...
Key Message(s):

- Upper ridge continues to bring above average temps.
- Afternoon and evening precipitation is possible each day,
  mainly across the northern CWA Monday and western half
  Tuesday.

Upper ridging is expected to be over the area as surface high
pressure is filtered into the region from the Northeast to
start the short term period. Meanwhile, an upper trough is
forecast to continue developing over the Upper Midwest. All of
these features slide eastward over the short term period. The
ridge axis will continue across the region Monday, but begin to
shift off the coast by Tuesday. Multiple shortwaves are
forecast to ride around the periphery of the ridge as it passes
overhead, bringing chances for precipitation to the northern
half of the forecast area each afternoon and evening. Also, the
upper trough is anticipated to dig southward and assist in
developing a surface frontal boundary, resulting in southwest
flow locally by Tuesday afternoon and Tuesday night. The
southwest flow will likely lead to increased moisture to the
region ahead of the frontal boundary, bringing slightly higher
chances for precipitation on Tuesday. Due to the ridging,
temperatures are expected to remain on the warm side, with highs
in the mid 80s north to lower 90s south each day. Overnight
lows remain above normal with lows near/around 70 degrees.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Key Message(s):

- Chances for precipitation increase in the long term despite
  forecast uncertainty regarding tropical development and
  eventual track.


The uncertainty has decreased slightly regarding the increasing
chances for precipition across the Southeast this upcoming week.
However, the uncertainty remains pretty high regarding the
development, strength and track of the potential tropical
system. The NHC has increased the chance of development to 80
percent between days 3 and 7. The two main features causing
uncertainty are the development and depth of the upper trough
across the Central Plains/Mid MS River Valley Region during the
early/mid week. The ECMWF/GFS/CMC indicate the trough over the
Plains will cutoff, but depth and placement will make for an
interesting interaction with the tropical system. So,
confidence is increasing the some tropical system will develop
in the Western Caribbean and Gulf of Mexico, but where it goes
and how strong it gets is where the uncertainty comes in. The
model ensembles continue to have a hard time placing a system
that has yet to form. Regardless of what happens, daily chances
for precipitation continue through the forecast period.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
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Generally VFR conditions expected through the forecast period
except at KAGS which may see usual mvfr/ifr visibilities
overnight near the river.

Lingering late evening showers are diminishing and have shifted
south of the terminals, with mostly clear skies at the terminals
expected through the remainder of the night. Near calm to light
and variable winds expected through sunrise and will support
the potential for a little ground fog at the normally
susceptible AGS TAF site, but no restrictions expected
elsewhere. Winds pick up from the south today around 5 to 7
knots after 15z with afternoon VFR cigs as cumulus clouds
develop with strong surface heating. Cannot rule out isolated
convection once again this afternoon at the terminals but
confidence in impacts and timing not high enough to warrant
including more than VCSH at this time.

EXTENDED AVIATION OUTLOOK...There are no significant concerns
for restrictions at this time.
-- End Changed Discussion --

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$

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