605
FXUS62 KCAE 220531
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
131 AM EDT Sat Jun 22 2024

.SYNOPSIS...
Moisture will increase across the area over the weekend as low
pressure approaches from offshore. Above normal temperatures
are expected by Sunday into early next week. Heat Advisories
may be possible from Monday through Wednesday. Expect scattered
diurnally driven showers and thunderstorms for much of the
short and long term forecast.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
KEY MESSAGES:

- Tropical wave/low pressure will result in increased humidities.

The center of the tropical low and associated wave will move
onshore near the Florida/Georgia Atlantic border shortly after
sunset. Low level moisture has been surging in from the
southeast on the north side of the wave, and will continue to do
so overnight. Dew points have already risen into the 70s in the
southeasternmost counties, and that should make it to the I-20
corridor by midnight and over the entire FA by morning. The
increase in moisture should help promote some patchy ground fog
in the eastern half of the area toward sunrise.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SUNDAY/...
KEY MESSAGES:

- Increasing moisture will lead to a chance for afternoon and
evening thunderstorms.

Surface low pressure will move south of the forecast area on
Saturday with deep easterly flow leading to increasing moisture.
PWAT values rise to 1.75 to 2.00 inches, near to slightly above
normal, with highest values to the south. Expect showers and
thunderstorms to develop in the afternoon as the air mass becomes
conditionally unstable through daytime heating. We would expect
coverage to be highest across the southern Midlands and CSRA where
moisture is deeper and due to stronger subsidence to our north. Low
lapse rates point to limited updraft strength and a low threat of
severe weather. Convection should diminish in the evening with loss
of daytime heating, however as moisture advection increases through
the night we may see an isolated shower pop up during the early
morning Sunday.

Temperatures will be around normal in the low to mid 90s. Lows
overnight will be mild in the low to mid 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
KEY MESSAGES:

- Temperatures rise late this weekend into mid-week.
- Heat Advisory criteria possible Monday through Wednesday.

Daytime temperatures from Monday through Wednesday may be near 100
degrees. Varying levels of moisture during this period limit
confidence in reaching Heat Index values above 105. Daily showers
and thunderstorms could also hinder heating.

Late this weekend, 850mb temps warm leading to daytime highs rising
into the mid 90s for most areas. This warming trend continues into
Monday with highs into the upper 90s to near 100 degrees ahead of a
weak cold front which will bring drier air into the region. Much of
the area will be in northwest flow aloft with rather strong
downslope flow on Monday. The downslope flow would contribute to the
hot temps but would also dry out of the low levels. There may be a
period on Monday where lingering low level moisture combined with
warm temps raise Heat Index values into the 100 to 105 range.
However confidence in reaching Heat Advisory criteria is somewhat
limited by the potential for afternoon showers and thunderstorms.

With drier air over the area for Tuesday, rain chances and dewpoints
will be lower. Highs will still be in the upper 90s to near 100 but
with drier air in place Heat Adv criteria looks less likely. Global
ensemble means favor upper troughing in the Tennessee Valley moving
into the Southeast mid-week, pushing another weak cold front toward
the area. Moisture appears to increase again with over 75 percent of
ensemble member PWAT values over 1.5 inches by Thursday. Increasing
moisture and continued warm temperatures may push Heat Index values
to near Advisory criteria on Wednesday. A cold front pushing into
the Southeast late in the week and increasing cloud/precip chances
should promote slightly cooler weather towards the end of the long
term.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Low clouds beginning to move over the terminals early this
morning. Restrictions have moved over OGB and should move over
the Columbia terminals over the next hour or so. Highest
confidence in IFR ceilings at OGB so have left prevailing IFR
ceilings in there but have put IFR ceilings in a TEMPO group for
Columbia terminals with guidance trending more optimistic in
restrictions this morning. Restrictions should dissipate shortly
after sunrise with a cumulus field developing around 4kft.
Chances for showers and thunderstorms mainly for OGB and
possibly the Augusta terminals but confidence is a bit limited
to include in this TAF update.

Winds will generally be out of the ESE this morning, although
will likely become mostly light and variable in the pre-dawn
hours. Winds increase again late this morning, shifting out of
the SSE between 5 to 10 knots.

EXTENDED AVIATION OUTLOOK...Increasing chances for afternoon scattered
showers and thunderstorms and associated restrictions Sunday
through Wednesday.

&&

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

&&

$$