Area Forecast Discussion
Issued by NWS Columbia, SC

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000
FXUS62 KCAE 180653
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
253 AM EDT Mon Mar 18 2024

.SYNOPSIS...
Winds turning northwesterly toward daybreak and ushering in
cooler and drier air early this week. Some freezing temperatures
are possible Monday night and early Tuesday morning. Dry
weather and warmer temperatures follow during the middle of next
week. A storm system may develop across the southeast late in
the week.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
Light rain from the central Midlands through the CSRA will move
through the area over the next several hours then offshore
during the early morning hours. Rainfall amounts with this
shortwave have been light with most locations at a tenth of an
inch or less so far and another couple hundredths possible. Even
as this shortwave moves through the area through late tonight
clouds will persist over the area through sunrise when drier air
begins spreading into the region. Winds will remain westerly at
5 to 10 mph through the early morning then veer to northwesterly
as the shortwave moves offshore. With the clouds and wind expect
overnight lows to range from the mid 40s in the western Midlands
to the low 50s in the eastern Midlands.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH TUESDAY NIGHT/...
The aforementioned front will push into the area early Monday,
with  a steep moisture gradient and wind shift to out of the
north- northwest. Dew points will fall from the 50`s to down
into the 30`s by late Monday morning. While winds will remain
fairly light with the initial frontal passage, winds will
steadily strengthen throughout the day, likely gusting over
20mph by mid-afternoon. A lake wind advisory may be warranted
but currently not thinking gusts will consistently reach 25
knots. Cold advection will consequently strengthen as a result
of the low level flow increase, so temps Monday will struggle to
warm much despite mostly clear skies and downsloping. Highs will
likely remain in the low 60`s for most of the area. The strong
advection will continue into Tuesday morning and drive temps
down into the low- mid 30`s for the entire area. A Freeze Watch
is in effect for our northern tier of counties, from Lincoln
across to the Chesterfield. Confidence is relatively high for
these locations given the strength of the cold advection and
quite unanimous agreement across guidance. The next tier
southeast is a bigger question with NBM members about 50%
suggesting sub- freezing temps; however, climatologically,
strong north-northwest flow does not typically allow for sub-
freezing temps in the Columbia and Augusta metro and surrounding
areas. So did not add any counties to the Freeze Watch, but
additions may be needed if forecast trends change. Frost is not
expected regardless of freezing temps as winds and mixing should
prevent formation. Regardless, following the cold start,
Tuesday temps will run below average with high confidence. Highs
will likely top out right around 60 for most of the area.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Deep northwest flow will develop for Wednesday and Thursday,
with very dry air remaining entrenched as a weak dry front
pushes through late Wednesday into Thursday. NBM distributions
are in good agreement that temps will warm back above average
quickly both days thanks to downsloping aloft and weak southerly
component flow at the surface. There is quite a bit of
uncertainty as we reach late in the week, as a formerly cutoff
trough ejects eastward out of the SW CONUS. GEFS and EC
ensembles are actually in good "agreement" that there is quite a
wide range of uncertainty with this system. Both ensembles have
extremely large spreads in total QPF through Saturday, with as
many solutions suggesting a dry forecast as those suggesting 1"
or more. Based on the 500mb anomalies from the ensembles, it
appears that the uncertainty is arising from how the 500mb
trough develops and deepens as it moves off the coast. Again,
numerous members suggest a southern suppressed system, while
others develop a strong coastal low. Despite the lack of
agreement in ensemble guidance, rain chances are increasing as
we move into next weekend as regardless of solution thanks to
high probability of PWAT`s and moisture increasing along with
some sort of forcing from a mid- level trough.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR Conditions currently in place at all terminals as of 6z.
There remains some lingering low clouds around OGB which may
bring tempo low MVFR ceilings over the next couple hours but as
a cold front continues to move into the area, drier air should
move into the low levels. VFR conditions continue into today
with some lingering high based cumulus clouds, around 7kft. As
strong high pressure drops into the southern US, a strengthening
pressure gradient across the area with lead to strengthening NW
winds by mid-afternoon with gusts above 20 knots continuing into
tonight.

EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected Monday night through Thursday. Rain and associated
restrictions possible Friday.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Freeze Watch from late tonight through Tuesday morning for
     SCZ016-018-020-021-025-026-115-116.
GA...Freeze Watch from late tonight through Tuesday morning for
     GAZ040-063-064.

&&

$$


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