St. Andrews, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

642
FXUS62 KCAE 090933
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
533 AM EDT Wed Jul 9 2025

.SYNOPSIS...
A bit cooler Wednesday with widespread showers and storms likely
as a upper trough approaches. Some damaging winds and flash
flood possible with the stronger storms and heavy rainfall
Wednesday and Thursday. Temperatures slowly rise in the late
week and into this weekend with typical summertime
showers/storms.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Message(s):

- Widespread storms expected this afternoon with an associated flash
flood and damaging wind threat this afternoon & evening.

An approaching mid-level trough across the TN Valley will provide
sufficient synoptic scale forcing for widespread convection this
afternoon and evening across the area. As southwesterly flow
strengthens, moisture convergence ahead of this trough will
increase and push PWAT`s over 2.0" for much of the area. With
surface dew points remaining in 70`s throughout the day,
sufficient instability with over 2000 j/kg ML CAPE is expected
to develop by the afternoon. DCAPE however will be limited today
as deep moisture advection will yield a fairly saturated
sounding aloft. Overall, this combination of factors will
present both a flash flood and severe thunderstorm today. The
flash flood threat is supported by the high PWAT`s and expected
training storm motion with unidirectional light southwesterly
shear; HREF LPPM highlights potential of 3- 5" in isolated
spots which seems reasonable. While a favorable flash threat
setup exists, thankfully soil moisture is still quite dry and
our basins are not primed. As for severe, the threat is from
classic saturated pulse thunderstorms, bringing a damaging wind
threat primarily. Based on the environment and coverage
expected, this will be a quantity over quality when it comes to
severe, with some strong- severe storms possible given the
widespread coverage. The HREF shows some signs of organization
later this evening, closer to the shortwave forcing across the
northern Midlands and Pee Dee; this will likely be dependent on
cold pool development in the afternoon. WPC has expanded their
Slight ERO for our entire area and SPC has continued their
Slight Risk for the northern Midlands, with Marginal elsewhere.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Key Message(s):

- Partly to mostly cloudy with seasonable daytime temperatures.

- Potential for convective development during the afternoon and
  evening hours both days. A few thunderstorms may become
  strong, especially on Thursday.

- Flash flood potential continues through the period due to high
  moisture and weak steering flow.

The upper trough moves out of the Great Lakes region at the
start of the short term, passing to our north and being
replaced with weak ridging by Friday night. This will likely
result in unsettled weather across our FA during the short term,
with showers and thunderstorm possible both days. The expected
clouds and rain will result in more typical daytime temperatures
for early July with forecast highs in the lower 90s. Given the
lack of overall forcing, pulse convection will be favored and
largely driven by where instability is able to develop and any
lingering mesoscale boundaries from the previous day`s
convection. While organized severe thunderstorms are unlikely,
any robust thunderstorm has the potential to produce damaging
downburst winds and perhaps some small hail. This is reflected
in the wind driven Marginal (1/5) risk for severe weather across
the CWA on the latest Day 3 SPC SWO. Long, skinny CAPE profiles
in modeled soundings indicate a continued flash flood potential,
with the entire FA in at least a Marginal (1/4) risk for
excessive rainfall on Thursday. A Slight (2/4) risk is
maintained near the North Carolina border. The northern half of
the CWA is in Marginal risk for excessive rainfall on Friday.
Outside of locations that are normally prone to flash flooding
such as Five Points, the flash flood risk should be highest in
areas that receive several days of heavy rainfall as antecedent
conditions are not particularly concerning for a more widespread
flooding event. Having said that, any slow moving and/or
training thunderstorms can cause issues given the ample
atmospheric moisture available.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Key Message(s):

- Temperatures return to above normal values this weekend into
  Monday as upper ridging redevelops.

- The ridging should limit diurnal convection with lower
  probabilities expected through Monday.

- The ridge may break down early next week as an upper level low
  attempts to move in from the southeast.

Upper ridging should be in control of the Southeastern US during
much of the extended, resulting in hotter daytime temperatures
and lower chances for showers and thunderstorms. Hot and humid
conditions are expected this weekend with heat indices around
105 degrees on Sunday and Monday. More isolated showers and
thunderstorms are expected as convection is likely suppressed
by the aforementioned upper ridging. This ridging could begin to
weaken near the end of the period as an upper low to the
southeast attempts to move in. This potential is indicated in
the mid-range guidance by a decrease in temperatures and an
increase in precipitation chances.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
Stratus-fog possible this morning with LIFR-IFR restrictions.
Widespread storms likely this afternoon and evening.

Increasing moisture across the region will yield a stratus deck that
is expected to develop between 09z and 11z for all TAF sites;
OGB is already down to LIFR-IFR stratus-fog. Expected some IFR
cigs with this deck elsewhere, lasting through 13z or so this
morning. Beyond this morning, typical summer cu expected before
widespread storms develop across the area this afternoon and
evening. Timing is still a little uncertain, but tempo and
predominant groups will likely be needed in the next TAF
updates. Lingering convection is expected well into the evening,
possibly as late as 06z Thursday.

EXTENDED AVIATION OUTLOOK...There is the possibility of
diurnally driven showers and thunderstorms this week with the
potential for periodic restrictions.

&&

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

&&

$$

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