918
FXUS62 KCAE 220244
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1044 PM EDT Thu Aug 21 2025

.SYNOPSIS...
A retreating upper ridge breaks down today and allows Hurricane Erin
to pass offshore of the United States. Increased chances of
rain today through the weekend with a heavy rain threat. Cooler
temperatures expected Friday and Saturday due to developing
upper troughing. Cold front late in the weekend will usher in a
drier and cooler air mass for next week.

&&

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

- Heavy rainfall possible, especially in the western Midlands
  and CSRA.

A weak front continues to work across portions of western SC and
eastern GA, focusing stronger convection across those locations.
The front is effectively stationary in the western portions of
the fa and has pushed southeast into the coastal plain
elsewhere. Moisture convergence along the stalling portion of
the front is clearly evident in the instability fields with
1500+ j/kg ML CAPE across the western Midlands and CSRA, but
less than 1000 j/kg in the central and eastern Midlands. PWAT`s
are also slightly higher along the stationary front, over 2.2".
So with ample instability in western areas, lingering scattered
heavy showers and thunderstorms are likely late into the
evening. Some very heavy rainfall is the primary threat with
these storms, along with some sub-severe gusty winds. Convection
will eventually wane overnight into Friday morning, with some
low stratus possible in the morning.

&&

.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Key Messages:

- A weak frontal boundary stalls just south of the area Friday
  and remains there through Saturday.

- This front along with upper troughing should drive scattered
  to widespread showers and storms, especially across the
  southern counties.

- Heavy rainfall will be the primary risk from this activity
  each day.

A weak surface trough will move through the southern forecast
area, then stall out through Saturday. Aloft, an upper trough
axis will be situated just off to the west, with weak shortwaves
moving through the region. Moisture content remains high, with
pwat readings continuing above 2 inches, especially in the CSRA
and southern Midlands. A few showers possible to start off
Friday, then the guidance is indicating a shortwave approaching
during the afternoon and evening. This will help to enhance
convergence and lift along the front, increasing rainfall and
isolated thunderstorm coverage during the afternoon and
evening. With weak steering flow, activity expected to be slow
moving, leading to the heavy rainfall and flooding/flash
flooding potential. Guidance still showing areas of 2-4 inches,
with isolated higher amounts possible through Friday night in
the south. Lower amounts across the northern Midlands. The heavy
rain threat should continue through Saturday as an area of weak
low pressure develops and moves along the surface front off to
our south. 850mb winds north of the front turn more easterly off
the Atlantic, bringing more moisture inland through the day.
Greatest flood risk on Saturday may be along areas that receive
substantial rainfall on Friday. Due to the sustained heavy rain
threat through the period, have issued a Flood Watch for the
entire CSRA and southern portions of the Midlands from Friday
morning through Saturday night.

Cloud cover and rainfall should help to keep temperatures on the
cooler side both days, with highs only in the lower 80s
expected.

&&

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

- Stronger cold front pushes through the region Sunday, driving
  more showers and storms.

- Behind the front, drier conditions and cooler air moves in
  for the early week and into the mid week.

Little change in the longer term thinking. Deepening upper
trough moves into the eastern US Sunday, helping to drive a
strong cold front through the region into Monday. Ahead of the
front, decent moisture should allow for more showers/storms
throughout the afternoon and evening on Sunday but by Monday,
and especially Tuesday-Wednesday, much drier air will filter in
with PWAT`s dropping substantially. This will lead to a period
of drier weather through mid-week. In addition, after warmer days
on Sunday and Monday (highs in the mid to upper 80s), the much
drier and cooler temperatures will push in on Tuesday through
Thursday. With less humidity to deal with, it will definitely
feel refreshing out there.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Showers and Thunderstorms Possible This Evening, Mainly at
AGS/DNL....

Radar this evening shows showers approaching CAE/CUB from the
west with developing showers and a few thunderstorms around
AGS/DNL. Brief restrictions are possible during the next few
hours as this activity winds down. Will need to monitor to see
if any rain can reach OGB which has a dry forecast for tonight
currently. Once convection dissipates, the next period of
possible restrictions comes towards daybreak when low clouds may
develop. AGS is the likeliest overall to see restrictions, with
IFR to potentially LIFR ceilings possible there given the
rainfall that fell this afternoon and what is moving through
this evening. Ceilings should return to VFR around midday when
another round of convection is expected during the afternoon and
evening hours.

EXTENDED AVIATION OUTLOOK...Restrictions become increasingly
likely into the weekend as deep moisture returns to the region.
Showers and thunderstorms are also likely on Saturday
afternoon.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Flood Watch from 8 AM EDT Friday through late Saturday night
     for SCZ018-025-030-035-041-135>137.
GA...Flood Watch from 8 AM EDT Friday through late Saturday night
     for GAZ040-063>065-077.

&&

$$