297
FXUS62 KCAE 181635
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1235 PM EDT Mon Aug 18 2025

.SYNOPSIS...
Another hot and humid day is expected today before wedge-like
conditions develop on Tuesday and Wednesday. Showers and
thunderstorms are possible early this week, but coverage should
be limited. A retreating upper ridge breaks down on Wednesday
and allows Major Hurricane Erin to pass offshore of the United
States. More typical rain chances should return by the end of
week with cooling temperatures due to developing upper
troughing.

&&

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

- Warm and muggy day with heat indices between 100F and 105F

- Isolated showers/storms possible during the late afternoon
  and into the evening.

Despite high humidity and heat continuing across the region
today, the beginning of the day has been quite beautiful to
start. Skies are sunny and winds are light and we were even a
tad bit drier than we have been lately to start the day. That is
changing as a weak back door front slowly pushes southward
towards the area. This is noted in instability and moisture
fields, with a pool of higher PWs (1.6"-1.9") pushing towards
the area. Seasonal values of instability (1500-2500 j/kg) are
forecast to develop along and ahead of this feature this
afternoon as it pushes southward. As a result, isolated to
scattered showers/storms are forecast to develop this afternoon,
especially in the central and northern Midlands this afternoon.
HREF LPMM for composite reflectivity shows a good bit of
activity in this area, overlapping with a decent environment for
a strong storm or two to develop as well. HREF mean soundings
show 800-1000 j/kg of DCAPE & TEI Values >25, which favors some
downbursts with the strongest activity this afternoon. The
coverage should remain limited enough to keep this only with the
strongest storm or two of the day though. Highs this afternoon
will likely settle in the low to mid 90s, with peak Heat Index
values of 100F-105F. Overnight tonight, any convection that does
remain should diminish fairly quickly with lows falling into
the low to mid 70s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Key Messages:

1) Tropical Cyclone Erin Will Remain Offshore with No Direct Impacts
Expected

2) Trending Drier through the Period with Breezy Winds Developing on
Wednesday

3) Slightly Cooler and Less Humid

Tropical Cyclone Erin will remain offshore the US East Coast through
the period while lifting northward in the western Atlantic Tuesday
into Wednesday, before making a more northeastward turn Wednesday
evening into Wednesday night. Meanwhile, sfc high pressure will
gradually weaken while retreating northeast of the forecast area
through the period. With Erin remaining offshore, no direct impacts
are expected for the CAE forecast area. Diurnal scattered showers
and thunderstorms remain possible on Tuesday (NBM PoPs actually
trended upward this new forecast cycle) but confidence is low as the
12Z CAMs depict mostly dry conditions with the exception of isolated
activity possible across the far southern and eastern fringes of the
forecast area. The NBM continues trending dry for Wednesday thanks
to subsidence around the periphery of Tropical Cyclone Erin
developing over the central and eastern Carolinas. 12Z CAMs seem to
be in agreement with the NBM regarding dry conditions so confidence
on NBM PoPs is higher for Wednesday. Otherwise, it will be slightly
cooler and less humid through the period thanks to N/NE winds.
Breezy winds will develop on Wednesday as Erin makes its closest
pass to the Carolina coast. At this time, gusts look to remain below
20 mph across the CWA. Highs each afternoon will range from the
upper 80s to lower 90s with lows each night in the lower 70s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Key Messages:

1) Tropical Cyclone Erin Continues Lifting Northeast Away from the
East Coast

2) Cooling Trend Expected Friday into Saturday Before Warming Trend
Returns Sunday into Monday

3) Shower and Thunderstorm Chances Ramp Up through the Weekend

Tropical Cyclone Erin will continue lifting northeast away from the
East Coast through the weekend. Thus, direct impacts from Erin are
not expected for the CAE forecast area through the long term.
Subsidence around the periphery of Erin may once again allow for
mostly dry conditions on Thursday but confidence is low at this time
with this being day four and with the latest NBM having mentionable
PoPs across the western half of the forecast area on Thursday.
Shower and thunderstorm chances will gradually ramp up Friday into
the weekend as a cold front approaches out of the west. The front
looks to track across the forecast area overnight Sunday into early
Monday morning, possibly bringing back drier conditions behind it to
start the workweek. Highs should remain in the upper 80s to lower
90s on Thursday, falling into the lower to mid 80s each afternoon
Friday and Saturday. The warming trend may return Sunday into Monday
with highs each afternoon climbing into the mid to upper 80s. Lows
each night will range from the upper 60s to lower 70s.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
Earlier restrictions have diminished across the area with sunny
skies currently. By this evening, showers and storms are
expected to develop especially at CAE/CUB/OGB.

We had some fog and stratus issues at the typical sites, AGS and
OGB, this morning. However, these restrictions alleviated by the
rising sun and increase in temps. Skies are mostly sunny as of
this writing, and cumulus is likely to develop quickly over the
next couple of hours. A pocket of drier air is noted in WV
imagery across the southern portion of our forecast area, with a
southward moving boundary pushing better moisture towards the
Midlands TAF sites. Scattered showers and storms are expected to
develop later this afternoon and evening, with a Pro30 group in
place for thunderstorms this evening at CAE/CUB/OGB. Winds could
gust to 30 knots, along with low visibilities in any storms.
AGS/DNL will likely be too far south to actually deal with any
activity this evening, keeping the Prob30 out of there for now.
Tonight, clear skies are expected again with the possibility for
AGS and OGB to see similar conditions to what they did this
morning. Will introduce a TEMPO group to account for ground
fog/low clouds again beginning at 06z, similar to what happened
today.

EXTENDED AVIATION OUTLOOK... Morning restrictions remain
possible at prone TAF sites, with afternoon restrictions again
possible in showers/storms on Tuesday. Wednesday and Thursday
look drier, with an increase in moisture and storm chances this
upcoming weekend. Restrictions are possible in this convective
activity.

&&

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

&&

$$

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