416
FXUS62 KCAE 121814
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
214 PM EDT Sun May 12 2024

.SYNOPSIS...
High moves offshore Monday and increasing moisture supports an
unsettled week with chances for showers and thunderstorms for
much of the week. A bit drier air moves in for Thursday before
moisture returns for the weekend. Temperatures near to slightly
below average.

&&

.NEAR TERM /THROUGH TONIGHT/...
Dry conditions will prevail through tonight as high pressure
slowly moves off the coast. Should begin to see a slight
increase in moisture late tonight on the back of the surface
high, but not enough to bring in any rain chances. Scattered
cirrus will be the primary clouds through the period, with a few
fair weather cumulus through the afternoon in the mid-levels.

Temperatures in the lower 80s still on track for afternoon
highs. For tonight, although winds will become light and low-
levels will still be somewhat dry, there should be some high
clouds across the area to limit ideal radiational cooling for
most of the cwa. Overnight lows will drop into the mid to upper
50s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Upper ridge axis in place will shift to the east with southwest
flow developing over the forecast area. This will lead to deep
layer moisture increasing through the course of the day,
beginning in the mid and upper levels with forecast soundings
indicating it will take a bit longer to saturate the lower
levels. SREF mean runs have been trending wetter, however,
especially for the CSRA so pops have continued to increase, with
highest precip potential in the second half of the day. High
temperatures have trended a degree or two cooler in the CSRA as
a result with highs in the mid-70s to low 80s in the east.
Monday night, a warm front along the Gulf will begin to lift
northward towards the forecast area with increasing isentropic
lift leading to more widespread showers and potentially some
elevated thunderstorms with forecast soundings indicating some
instability above the surface.

HREF mean indicates that PWATs Tuesday will climb to above 1.6
inches across the entire area with forecast soundings showing a
near saturated column from the surface to the upper levels.
While there is likelihood of rain at times on Tuesday, there
does remain plenty of uncertainty. A shortwave will push through
the forecast area with uncertainty as its timing with a later
timing causing more concern for the potential for severe weather
as deep layer shear will support organized storms if they can
develop. Another question mark is the potential for an MCS to
form along the Gulf Coast and move east, which would likely miss
us to the south and typically is a climatologically favored
"failure mode" for significant and widespread convection over
the area. For now, the SPC places most of the area in a marginal
risk for severe weather and we will have to closely monitor
upstream development along the Gulf over the next couple days.
Any convection that does develop will produce locally heavy
rain. Behind the shortwave that moves through the area, models
do indicate a dry slot pushing into the area for Tuesday night.
Temperatures will be similar to Monday.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The upper trough associated with our significant increase in
moisture will move over the area Wednesday and while ensemble
means indicate PWATs will decrease slightly, lift provided by
the upper trough and high probability (60 to 70 percent) of
PWATs greater than 1 and a quarter inch in the northeastern
portion of the area will support scattered to widespread showers
and storms, especially in the Pee Dee. Upper ridging over the
forecast area develops Thursday with subsidence generally over
the area, limiting convection. Ensemble members show an increase
of moisture once again for late week into the weekend which will
keep the weather unsettled, although there is some uncertainty
in the progression of a couple upper systems which will provide
forcing to the area.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
High confidence remains in VFR conditions through the TAF
period.

High pressure moving slowly through and east of the forecast
area through tonight. Airmass will continue to be rather dry,
with mainly some scattered to broken cirrus moving in from the
west. Only a few mid-level fair weather cumulus this afternoon
which will dissipate by sunset. Increasing clouds become more
likely Monday morning ahead of the next system. Much of the
cloud cover will remain in the mid to upper levels through 18z
Monday. Can not rule out a passing light shower late in the taf
period in the CSRA, but confidence not high enough to place in
tafs. Do not expect any fog formation overnight. Winds out of
the northwest through this afternoon, then light to calm
overnight. Winds turning more out of the south to southeast
through the day Monday.

EXTENDED AVIATION OUTLOOK...Showers and thunderstorms and
associated restrictions are possible late Monday through
Wednesday.

&&

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

&&

$$