280
FXUS62 KCAE 040257
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1057 PM EDT Tue Jun 3 2025

.SYNOPSIS...
Dry again tonight, but with increasing moisture. With this
increasing moisture, chances of rain return starting Wednesday
with additional scattered showers and thunderstorms forecast
to return by the end of the week into the weekend.

&&

.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
Key Message(s):

- Dry, but moisture increasing overnight.
- Overnight lows moderating slightly.

Upper air analysis shows an upper low currently located near the
big bend of Florida. Meanwhile, surface analysis indicates a
high pressure centered off the Mid-Atlantic/New England coast.
As a result, southeasterly low-level flow has developed, which
has brought in some increased moisture to the area, mainly for
the eastern portions of the forecast area so far. Expect the
upper low to drift northward overnight, while the surface high
remains relatively stationary. This should allow for continued
moisture advection into the area as well as an more mild lows
tonight. With the increased moisture and approaching upper low,
there is a low chance (~15%) for showers to move into the lower
CSRA around daybreak.

&&

.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Key Message(s):

- Better rain chances possible beginning Wednesday
  afternoon/evening where periods of moderate to heavy rain
  will be possible.

- Rain chances continue into Thursday with some storms possible
  as well.

Wednesday and Wednesday night: A closed upper low is expected
to continue to drift northward from the Florida Panhandle up
into the region through the day Wednesday. At the surface, an
inverted trough will work into southern SC by the afternoon
along with a slowly developing area of low pressure along the
coast. This will create strong southeasterly moisture advection
where PWAT`s surge above 2" (near 150-160% of normal) across
much of the FA south of I-20 and the upper low brings a lobe of
PVA into the area. This will drive rain chances especially in
the southern CSRA and along/south of I-20, starting more
isolated in the morning before becoming scattered to widespread
into the late afternoon and evening. Some embedded thunderstorms
will be possible in this activity with the high moisture
content, but with the expectation of general cloud cover,
instability is rather limited and temperatures maybe kept in
check due to this in the upper 70s to low 80s. Thus, the risk
for any severe storms is low. Due to the deep moisture, good
forcing, and fairly deep warm cloud depths in forecast soundings
during the afternoon and evening, periods of moderate to heavy
rain will be possible, which is covered well in WPC`s Marginal
Risk (level 1 out of 4) for excessive rainfall that outlines the
portion of the CWA along and south of I-20. The better rain
chances shift slightly northward overnight and into Thursday
morning with the paired upper low and inverted trough at the
surface.

Thursday and Thursday night: The upper low continues its trek
toward the northeast through the day Thursday, though becoming a
bit more open. This along with a inverted trough lingering in
the region will maintain fairly strong moisture advection from
the southeast to south-southeast as PWAT`s remain between 1.8-2"
much of the morning and into the afternoon. This will continue
to drive efficient warm rain processes and periods of moderate
to heavy rainfall as warm cloud depth will be between 3-4km,
little dry air in the low levels will be present for
evaporation, and some long skinny CAPE profiles are expected.
Due to this, the WPC maintains a small Marginal Risk for
excessive rainfall on a line from Bamberg County through
Orangeburg County and into Sumter County. There is some signal
in LREF guidance and in the experimental RRFS that some more
thunderstorm potential is there during the afternoon as some
breaks in clouds maybe possible, but at this time the severe
threat looks fairly limited with weak Bulk Shear generally under
20 kts. Subsidence is then expected into the evening and
overnight on the backside of the upper trough with PWAT`s
dropping slightly and thus lower PoP`s into Friday morning.

In terms of temperatures Thursday, with cloud cover and rain
continuing much of the morning and into the afternoon, cooler
temperatures in the upper 70s to low 80s are expected.

&&

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

- An active pattern is expected during the extended period, with
  multiple chances for showers and thunderstorms.

_ Warm and muggy conditions expected into early next week.

Things are looking to remain more on the active side into the
extended period with a couple key features in play. First, a
general upper troughing pattern is expected to continue into
early next week, with a deeper trough nearing the region by the
weekend and into early next week. Also, a coastal low is
expected to continue to develop off the SC coast Friday and into
the start of the weekend, aiding in maintaining PWAT`s
generally above the NAEFS mean of 1.50" through much of the
period. This combination of features will drive daily rain/storm
chances, mainly Saturday through early next week, as some
subsidence Friday will keep chances on the lower end. No one day
stands out in the EC EFI for greater chances for any potential
severe weather but some ensemble and ML guidance shows that
there could be greater chances for a couple stronger storms over
the weekend as greater shear moves in with the stronger
troughing. For temperatures, daily highs look to be around
average to just above average with muggy conditions.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions expected through early tonight, MVFR/IFR ceilings
likely early morning Wednesday potentially continuing through
the day.

Winds light and variable tonight. As an inverted trough lifts
northward along the coast tonight allowing for strengthening
onshore flow and moisture advection. The deepest moisture and
rainfall will likely remain south of the area through daybreak.
However guidance continues to show a stratus deck developing
along the coast and moving inland beginning around 09Z. There
has been a trend in guidance in the LAMP and HRRR for shorter-
lived IFR/LIFR conditions so we have narrowed the time frame
some.

After 12z, deeper moisture begins to move into the forecast
area from the south. We expect widespread MVFR, possibly IFR,
ceilings from Wednesday morning through 00Z as rainfall moves
into the area from the south. Highest confidence in showers and
thunderstorms will be in AGS/DNL where moisture and instability
are higher. Lower confidence to the north so we have opted for
a PROB30 group to express the uncertainty in visibility
restrictions from rainfall. Winds after 12z Wednesday will
remain easterly, increasing to between 5-10 knots.

EXTENDED AVIATION OUTLOOK...Continued rainfall and restrictions
into Wednesday night. Moisture remains in place over the area
through much of the extended leading to potential early morning
restrictions and diurnal convection each day.

&&

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

&&

$$