Area Forecast Discussion
Issued by NWS Columbia, SC

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000
FXUS62 KCAE 171302
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
902 AM EDT Sun Mar 17 2024

.SYNOPSIS...
A weak area of low pressure moving northeast along the coast will
generate scattered showers mainly south of I-102 late today and this
evening. A cold front will move through the region tonight, ushering
in cooler and drier air early in the 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 /THROUGH TONIGHT/...
Satellite imagery this morning indicates increasing clouds across
the state. A surface cold front has shifted offshore, and an
approaching mid-level shortwave is generating an area of showers
across central GA. With a deepening upper trough pushing into the
Midwest, do expect flow aloft to shift slightly southwesterly,
allowing better moisture to return to the forecast area. The
aforementioned shortwave is progged to move through the area late
this morning into the early afternoon, bringing the showers along
with it. HiRes guidance is generally supportive of this scenario,
and PoPs were adjusted slightly to show an earlier arrival of some
showers into the CSRA. However, forecast soundings do indicate a
substantial dry layer below 10,000 feet so precip may struggle to
reach the ground. As a result, PoPs are generally still on the lower
side through early afternoon before the entire column moistens
further by this evening. With more cloud coverage today and likely
some evaporational cooling, highs will be cooler, in the upper 60s
NW to mid 70s SE.

A stronger shortwave, currently visible generating thunderstorms
in south Texas is expected to move into the area by this
evening. The general trend has been a more suppressed solution
to the south which will favor rain chances south of I-20,
although chances will be higher in this area by evening then
they will be during the afternoon. Even with the possibility of
showers, HREF mean shows the highest probability of total
rainfall greater than a tenth of an inch favoring the Coastal
Plain. As the shortwave pushes to the east, a strong cold front
will push into the area Sunday night which will usher in much
drier air with lows dropping into the mid to upper 40s.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
Short wave trough will be moving well east of the area Monday
morning. The amplified deep positively tilted long wave trough
extending from New England southwest to the Mississippi Valley
will be moving southeast across the Carolinas and Georgia later
in the afternoon and evening. Some lingering clouds expected as
the short wave approaches in the afternoon especially across the
northern Midlands. Cold advection weak through most of the day
so temperatures should rise into the mid to upper 60s. But a
secondary cold front will move through in the afternoon and cold
air advection will increase. Sky should clear behind the front
with strong downslope developing. 850mb temps fall to -3C to -5C
overnight. The surface pressure gradient tightens a bit late in
the day into the overnight between the weak low well offshore
and the high pressure/modified Canadian air mass center over the
southeastern Plains/lower Mississippi Valley. Expect northwest
wind gusts to around 25-30 mph into the evening. A Lake wind
advisory may be needed. The winds should diminish toward morning
with a clear sky. Model temperature consensus is suggesting >
60 percent probability of near freezing temperatures by morning
across the north Midlands/Piedmont and the northern portion of
the CSRA. Therefore, a freeze watch has been issued for late
Monday night into Tuesday morning for those areas. The low
temperatures are expected to be in the low to mid 30s across the
region. Frost should be limited due to mixing in the boundary
layer.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Temperatures should rise above freezing shortly after 12z
Tuesday.

From Tuesday and beyond, northwest flow will generally develop
aloft and help advect dry air with below average PWAT`s through
Thursday expected. Temps will likely warm back above average as
downsloping and clear skies continues/air mass modification
each day. By late week, the GEFS and EC members are all hinting
at a cutoff trough ejection from the Southwest CONUS, then
pushing eastward. Confidence is quite low in any details as
there is wide intra- and inter-ensemble spread but PWAT`s look
likely to increase by week`s end along with some sort of
synoptic level disturbance. The ECMWF members are weaker/less
amplified and further south with the deep moisture than
GEFS/GEPS. The NBM pop guidance is in the chance category
Friday into Saturday.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
VFR conditions anticipated through the TAF period.

Mid and high SCT-BKN clouds much of the day with CIGs lowering to
around 6-8kft MSL. ISOLD-SCT -SHRA mainly for AGS/DNL/OGB but
restrictions are not anticipated. SFC winds increase out of the west
by early afternoon between 10 to 15 knots. Rain chances generally
ending for the terminals after 18/03Z tonight with winds becoming
NWLY/NLY 6-10 kts through the end of the valid period.

EXTENDED AVIATION OUTLOOK...Breezy conditions possible Monday
afternoon/evening. No significant impacts to aviation expected
Monday night through Thursday.

&&

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

&&

$$


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