345
FXUS62 KCAE 011729
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
129 PM EDT Tue Jul 1 2025

.SYNOPSIS...
A bit cooler with widespread showers and storms Tuesday and
Wednesday. Rain will be moderate to heavy at times. Temperatures
recover to near average Thursday through the weekend with
isolated chances for afternoon storms.

&&

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

- An approaching front will bring showers and storms across the area
this evening.

Not too much change in the forecast thinking for this afternoon and
evening with an approaching trough and weak surface front nearing
the area. Abundant low-deep layer moisture has pushed PWAT`s back to
around 2.0" and surface dew points have held steady in the low-mid
70`s. Despite the approaching front, mid-level lapse rates will
remain fairly mediocre and surface heating will not be terribly
impressive either, yielding a modest ML CAPE environment in the
HREF suite (around 1000 J/kg). Again, despite an approaching
trough, there is only weak mid-deep layer winds associated with
it and therefore only modest shear. The HREF has been consistent
in producing widespread showers and storms this evening, which
lines up nicely with this type of modest forcing, modest CAPE,
and high moisture environment. Severe threat will remain highly
isolated given the lack of shear and weak downdraft potential
with a lack of DCAPE and dry air aloft. Some boundary collisions
or cell mergers could pop a severe storm however. Heavy rain
potential is present with these storms, but storm motion should
preclude much flash flooding threat. But like with severe, the
threat should be isolated but cannot rule out a few areas of
flash flooding given the high PWAT`s and efficient instability
profiles.

Convection is expected to linger into the evening hours particularly
across the western part of the area as the frontal boundary
approaches from the west but intensity should wane by late evening.
Widespread cloud cover overnight should limit radiational cooling
and expect lows to be in the lower 70s.

&&

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

- Widespread showers and storms continuing Wednesday with
  marginal flash flood risk in the southeastern area.

Upper trough will be shifting through the area Wednesday with a
cold front to the west, although HiRes guidance indicates there
will likely be a lull in shower or storm activity in the
morning with a capping inversion in place and notably, forcing
not looking quite as strong with the latest guidance. Still with
HREF mean showing PWATs above 2 inches and increasing low level
convergence, widespread showers and storms expected to develop
by the afternoon, with the heaviest rain favoring the eastern
portion of the forecast area where synoptic forcing will be
strongest in the afternoon. Similar to Tuesday, the pattern
supports a marginal flash flood threat with the southeasternmost
tier of counties in a marginal risk ERO from WPC. The limiting
factor will be storm motion with steering flow likely to exceed
10 knots. This will prevent widespread flash flooding issues but
rain will still be locally heavy at times. A bit cooler
Wednesday with widespread clouds and increased rain chances with
highs in the mid to upper 80s.

As the front moves offshore, drier air will work into the area
for Thursday with upper ridging beginning to build over the
central CONUS. Upper heights recover with blended guidance
favoring near normal temperatures. Forecast soundings indicate
significant moisture remaining in place below 10kft as humidity
remains high. With the front expected to stall near the coast of
SC, some uncertainty as to whether or not we could get shower or
storm development in the southeastern portion of the forecast
area.

&&

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

- Drier with seasonably hot conditions. Moisture begins to
  recover by the end of the weekend and into next week.

Global ensembles have trended drier in the extended, both in
deep layer moisture and also in the low levels as upper ridging
strengthens to the west of the area and northwest flow
develops. LREF indicates a relatively high probability (around
50 to 70%) of PWATs remaining below an inch and a half Friday
and Saturday before a gradual moisture increase with the latest
GEFS mean showing PWATs returning to near normal through the end
of the period. Seasonably hot conditions with the ridge
building to the west, although with this added dry air LREF mean
soundings show strong mixing, leading to a slight break from
the significant humidity earlier in the week. Worth mentioning
the the National Hurricane Center is monitoring the potential
for low pressure to develop along the front as it stalls
offshore and has a 20% chance of tropical or subtropical
development but even if there is development, impacts to our
area would likely be limited.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
Widespread showers and storms likely across western SC this
evening, with some impacts to the TAF sites likely.

Persistent stratus has lingered across the region this morning
with most sites still remaining MVFR. This should steadily
improve this afternoon, going VFR by 19z or so. Widespread
showers and storms are likely into the evening, with the best
potential between 22-02z. Including a tempo group at sites but
OGB for this period, with the expectations that showers-storms
will also linger beyond that. Associated restrictions possible
through Wednesday morning from convection and low stratus
developing thanks to abundant moisture. Winds will remain 8-12
knots this afternoon, out of the south, outside of any
convection.

EXTENDED AVIATION OUTLOOK...Patchy low clouds and/or ground fog
possible each night along with diurnally favored showers and
thunderstorms.

&&

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

&&

$$

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