278
FXUS62 KCAE 181430
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1030 AM EDT Sat May 18 2024

.SYNOPSIS...
Periods of showers and thunderstorms are expected today and
into tonight. Rich moisture across the region will keep rain
chances likely lingering into Sunday. Cooler and drier air moves
in for Monday and Tuesday with temperatures rebounding during
the middle of next week as another ridge moves in from the west.

&&

.NEAR TERM /THROUGH TONIGHT/...
An upper level low, part of a broader positively tilted upper
level trough, is centered over eastern Arkansas and western
Tennessee this morning. This upper trough, along with an
associated weak surface low pressure system, will move east
toward the area through tonight.

Morning shower activity will continue shifting east and
eventually out of the area by midday, leaving much of the early
to mid afternoon rain-free as convection across the Florida
Panhandle robs moisture advection into the area. Convection is
expected to redevelop later in the afternoon as forcing ahead
of the approaching upper trough increases across the area. The
higher resolution mesoscale models generally show the greatest
coverage of this convection across the northern Midlands and
into the Pee Dee into this evening.

The overall severe weather threat appears limited today, as
morning shower activity and abundant cloud cover will limit
instability. However, if storms do become strong or even severe,
the greatest potential appears to be across the northern
Midlands and Pee Dee where instability and forcing will likely
be greatest. Strong wind gusts appear to be the primary threat,
but there is some hail potential as well.

Temperature rises will be limited by the abundant cloud cover
today, but warm air advection with a southwesterly low level
flow in place should allow for highs in the upper 70s to lower
80s.

Any convection this evening should gradually wane as the best
lift moves out. It will remain cloudy though with temperatures
falling into the lower to mid 60s tonight.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Sunday and Sunday night...Highly positively tilted upper level
trough will be just west of the forecast area at daybreak and
gradually move eastward through the day reaching the coast by
Sunday evening. At the surface a weak boundary will be sinking
southward with winds turning northerly with passage and the
atmosphere becoming increasingly stable indicating wedge-type
conditions. The boundary will push into the northern Midlands
and Pee Dee by daybreak through the central Midlands during the
mid morning then begin weakening as it reaches the southern
Midlands and CSRA by mid afternoon. Although much of the
forecast area will see increasing stability there will be some
instability in the far eastern Midlands into the southern CSRA
which could generate a few thunderstorms if there are enough
breaks in the clouds to allow for sufficient heating. Overall
have lowered pops and increased clouds which has also resulted
in afternoon high temperatures also coming down a few degrees
with low 70s in the north and upper 70s to around 80 in the
southern Midlands and CSRA. Sunday night the upper trough will
continue slowly moving offshore with high pressure building in
at the surface. Model soundings indicate plenty of dry air
overtaking the region Sunday night however moisture will be
trapped near the surface resulting in partly to mostly cloudy
conditions overnight. With the continued northerly flow low
temperatures Sunday night will be in the upper 50s to around 60.

Monday and Monday night...Upper level ridging will be
approaching the region Monday and Monday night as the upper
level trough becomes nearly stationary over the western
Atlantic. High pressure will control the surface with dry air
dominating the mid and upper levels. Mid level lapse rates will
be 5.5 C/Km at best so any cumulus which form will be vertically
limited. Northerly flow will persist over the region so
although there will be partly to mostly sunny skies allowing for
plenty of sun expect afternoon highs in the upper 70s to low
80s. With little change for Monday night expect another night of
partly cloudy skies and overnight lows in the upper 50s to
around 60.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Upper level pattern remains amplified yet progressive through
the long term. Upper level ridging and weak surface high
pressure will remain in control of the area through Wednesday
night with the next frontal boundary currently expected to move
into the region Thursday. As it typical for this time of year
the front will struggle to reach the forecast area and stall
just to the northwest. This will result in the front acting more
as a focusing mechanism for showers and thunderstorms Thursday
and Friday with the highest pops over the northern Midlands.
Temperatures through the long term will be near to slightly
above normal.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Periodic Restrictions Possible through the TAF Period...

The morning shower activity has generally moved east of the
terminals as of late morning, but flight restrictions persist
at most terminals due to lingering low ceilings. Guidance
suggests that ceilings should improve around midday with a
return to VFR conditions in the afternoon. However, additional
showers and thunderstorms will be possible across the region
later this afternoon. The forecast will maintain VCSH after 21Z
due to low confidence in thunderstorm timing.

EXTENDED AVIATION OUTLOOK...Periodic restrictions from showers
and thunderstorms continue through Sunday night. Low ceilings
are also possible Sunday morning. Conditions should improve on
Monday.

&&

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

&&

$$