727
FXUS62 KCAE 171036
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
636 AM EDT Fri May 17 2024

.SYNOPSIS...
Chances of showers and thunderstorms will increase this
afternoon as a weak system begins to slowly cross the region
with shower and thunderstorm 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/...
Change will begin this morning as winds turn south to
southwesterly. Although speeds will be less than 10 mph this
will begin advecting Gulf moisture into the area. By early
afternoon pwats will have crossed 1.5 inches and 1.8 inches by
early evening. Although this system is lacking a strong trigger
mechanism and mid level lapse rates will be around 5.0 C/Km
there is potential for strong heating should the cirrus be
thinner than expected. Current satellite imagery shows an
extensive cirrus deck over the western and central Gulf Coast
however much of this is due to a weakening MCS. Even with the
MCS cloudiness dissipating as it weakens expect the increasing
and lowering clouds through the day to limit heating and keep
the best chance of thunderstorms across the southern Midlands
and CSRA. SPC outlook has the area in general thunder with a
slight risk over the central Gulf Coast and should this area
become active it is possible for some to push into the CSRA
during the evening into early overnight hours. Overall agree
with the SPC outlook while there is potential across the
forecast area it is limited. Moisture and isentropic ascent also
increase through the evening into the overnight hours and with
pwat values increasing to 2 inches or better at times there is
potential for some locally heavy rainfall. Flow aloft will be 40
to 50 knots so do not expect any hydro related issues attm
however will continue to monitor. High temperatures this
afternoon will range from the low 80s in the western Midlands
and northern CSRA to the mid 80s elsewhere. Overnight lows will
be in the mid 60s to around 70.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Saturday and Saturday Night: Upper trough centered near Arkansas
at  the start of the day will move east towards the FA during
the period. Latest guidance suggests that rain on Saturday will
be more scattered in nature than previously thought. With this
in mind PoPs have been lowered, especially during the first half
of the day. Many of the CAMs, such as the 00Z HRRR, suggest
there will be a break in the convection with redevelopment in
the afternoon and evening hours. Thunderstorms will likely
increase in coverage later in the day as the aforementioned
upper trough approaches, perhaps providing enough lift to
overcome the lack of instability due to widespread cloud cover.
Another possible deterrent to thunderstorms on Saturday will be
the potential for widespread convection over the Florida
Panhandle which would block gulf moisture from reaching the FA.
In this scenario, we may see only isolated convection until the
trough arrives, as shown in the 00Z NAMNest.

The Day 2 SPC SWO has introduced a Slight (2/5) risk for severe
weather on Saturday for much of the forecast area. While
guidance continues to be quite aggressive with CAPE values,
especially across the southeastern CWA, the previously mentioned
concerns provide reservations regarding the overall severe
threat. Modeled soundings indicate modest directional shear and
the presence of mid-level dry air towards evening suggesting at
least a low-end threat for large hail and damaging winds. Will
maintain messaging that a few thunderstorms may become strong
favoring locations south and east of I-20 and revise as needed
with the next forecast package.

Regardless of convective evolution on Saturday, skies are
expected to remain cloudy for the day limiting temperatures to
the upper 70s and lower 80s for most locations. Evening
convection will likely wind down through the overnight as the
best lift passes to our east. Maintained chance PoPs through the
overnight period. Lows will be in the mid-60s.

Sunday and Sunday Night: Not much change in the weather is
expected on Sunday as the upper trough sluggishly moves
through the region. Guidance suggests shower and thunderstorm
chances will ramp back up during the daytime hours. With the
upper trough in place, will need to monitor for potential strong
thunderstorms though the SPC Day 3 SWO only has the region in
general thunderstorm for Sunday. It`ll be another cloudy day
with below normal daytime temperatures and above normal
temperatures at night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The upper trough sits off the North Carolina coast early next
week favoring a northerly flow over our area. At the surface,
an area of low pressure will also be centered to our east
ushering in cooler and drier air through northerly winds. Monday
will likely be the coolest day of the extended with gradually
decreasing cloudiness. Due to the proximity of the coastal low,
a few passing showers cannot be ruled out on Monday, especially
in the eastern half of the CWA. The low continues to pull away
on Tuesday allowing for more sunshine and warmer temperatures.
Weak ridging moves in by Wednesday allowing temperatures to
reach above normal values during the middle of next week. A cold
front approaches late in the period with a chance of showers
and thunderstorms, especially by Thursday.

&&

.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR conditions through mid afternoon then restrictions expected
for the remainder of the TAF period.

Cirrus continue to move in from the west as the MCS moves across
the FL Panhandle. Patchy fog in a few surface obs this morning
will quickly burn off with sunrise. Winds this morning will
become S to SW and begin advecting Gulf moisture into the area
with clouds increasing and lowering through the afternoon hours.
Expect SCT showers to begin developing around 18z and have
included VCSH for all terminals with predominant showers and
MVFR restrictions moving into AGS/DNL around 21z and spread
into the other terminals by 22z. Showers will decrease in
coverage around midnight however cigs will continue to lower
into low end MVFR possibly IFR from 18/05z through the end of
the period.

EXTENDED AVIATION OUTLOOK...Increasing confidence in
restrictions in showers and thunderstorms continuing through
Sunday night.

&&

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

&&

$$