529
FXUS62 KCAE 280713
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
313 AM EDT Sun Apr 28 2024

.SYNOPSIS...
Weak high pressure centered northeast of the region will remain
in control through Monday along with a warming trend. A weak
front is expected to bring a slight chance of showers and
thunderstorms late Tuesday through Thursday, mainly northern and
eastern areas.

&&

.NEAR TERM /THROUGH TONIGHT/...
Mostly cloudy skies across the region along with some patchy fog
and stratus which have gradually developed over the past couple
of hours. Through daybreak expect little change with some
additional stratus and fog developing where the mid and upper
clouds clear. Overnight lows will be in the mid to upper 50s.

High pressure will remain northeast of the region today and
tonight with a ridge of high pressure orienting east west across
the SE US. Flow will be turning southeasterly today while
continuing to advect moisture into the area. Although pwat
values will be 1.2 inches or better there will be a considerable
inversion aloft along with some dry air. This will leave a
limited layer of moisture in the low levels so expect some
cumulus to develop from mid morning through the afternoon
however vertical development will be limited and no rain
expected. This evening low clouds will begin to diminish with
sunset with mid and high clouds lingering over the area through
the night. High temperatures this afternoon will be in the upper
70s to low 80s with lows tonight in the mid 50s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Quiet weather is expected to continue on Monday, with high
confidence in the forecast. Latest ensemble and operation guidance
continues to show our pattern moderating downstream from the active
central Plains. A series of shortwaves and low pressure systems are
forecast to ride northeastward atop the ridge over the eastern US,
with fronts slowly pushing the low-level ridge axis southward. In
turn, our prevailing flow will shift from southeasterly to
southwesterly on Monday. As a result, warm air advection is likely
to be a bit more notable, with 850 hPa temps starting the day in the
12-14C range. This will allow highs to likely jump into the low and
mid 80s, with more sunshine aiding the warming trend. Rain is
unlikely as we`ll see subsidence under shortwave ridging, manifested
in a strong inversion showing up in model soundings between 750-800
hPa. Overnight, look for dry conditions to continue, with lows
in the upper 50s and lower 60s.

A slow moving shortwave trough is forecast to approach the forecast
area on Tuesday. Guidance has slowly trended towards a more
organized trough and a slower progression of said trough on Tuesday.
As a result, there is more forcing aloft for precipitation Tuesday
afternoon. Big however, though. Guidance is split on the amount of
moisture that will be in place ahead of this as the front and upper
level support approaches Tues afternoon/evening. Amongst LREF
guidance, GFS/GEFS are the most aggressive with rainfall chances,
while the ECM/ECE members are least aggressive. The Canadian ens &
operational model (and the early runs of the NAM) are somewhere in
the middle, which seems like a reasonable spot to be in currently.
The fly in the ointment is how much mixing we see by Tuesday
afternoon, which could lower our dewpoints and yield lesser
instability. I think the middle of the road is a good scenario here,
with scattered showers or thunderstorms developing by the afternoon
hours. Guidance (other than the ECM) is suggesting at least ~500
j/kg of CAPE developing for much of the area, which should yield the
chance of thunderstorms. With weak shear, though, anything severe is
unlikely. Highs will likely be in the mid to upper 80s across the
area. Some showers could continue into Tuesday night, with lows in
the low 60s.


&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Confidence in the long term remains fairly high. Front should slowly
push through the area on Wednesday, with all LREF members showing
afternoon/evening rain chances persisting as the front won`t totally
clear the region and moisture will remain in place ahead of it. Mid-
level ridging will again build in by late week, with temperatures
warming to near 90 Thur/Fri with subsidence aloft keeping us dry and
sunny. By Saturday and Sunday, ensembles and operational models
begin to show a more active pattern developing, with showers and
thunderstorms possible again. So in general, the short and long term
periods are fairly high confidence, especially with regards to above
normal temperatures developing. Confidence is also high that our
best chances of rain/storms will be Tues/Wed, & Sat/Sun.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Mainly VFR conditions through the period with restrictions
possible in stratus and fog through sunrise.

Satellite imagery and surface obs show plenty of clouds across
the region with some low clouds developing near the terminals.
Expect this to remain variable through sunrise as clouds cross
the area and disrupt the development of stratus and fog. ATTM
have included mention of scattered clouds around 1.5 kft with
TEMPO at AGS due to river impacts. A strong inversion will take
until mid morning to mix out and allow remaining low clouds to
dissipate then cumulus will begin developing from the mid
morning through the afternoon hours. With an inversion aloft
vertical growth will be limited and no rain is expected. Clouds
will diminish with sunset as some drier air finally moves into
the area. Winds through the period will be southeasterly at 8
knots or less.

EXTENDED AVIATION OUTLOOK...Restrictions possible in early morning
fog or stratus each morning. Slight chance of afternoon showers
and thunderstorms Tuesday onward.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...