737
FXUS62 KCAE 170537
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
137 AM EDT Sun Aug 17 2025

.SYNOPSIS...
Hot and mainly dry conditions are expected today as upper ridge
remains centered to our west. Showers and thunderstorms are
possible Monday and Tuesday, but coverage should be limited due
to the ridge, which breaks down on Wednesday and allows Major
Hurricane Erin to pass offshore of the United States. More
typical rain chances should resume to end the week with cooling
temperatures due to developing upper troughing.

&&

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

- An isolated shower/storm cannot be ruled out this afternoon
  and evening but most locations should trend toward the dry
  side.

- Temperatures warm slightly to right around average.

Radar has grown fairly quiet outside of a couple showers toward
the Coastal Plain and into the upstate as well. This activity
should continue to diminish overnight, but some lingering low
level moisture, especially in areas that saw rainfall yesterday
could lead to some patchy fog toward daybreak. The remainder of
the day sees upper ridging weakly build back in with drier air
being ushered in and overall subsidence. PWAT`s are expected to
not only drop under 2", but even under 1.5" through the day as
fairly unidirectional north to northeast flow throughout the
atmosphere moves in. This should lead to mostly clear skies with
strong insolation through the day that will allow afternoon
temperatures to reach the low 90s. In terms of rain chances, a
mostly dry day is expected due to the drier airmass and
subsidence that moves in. Forecast soundings show a fairly
strong subsidence inversion that will likely keep convection at
bay, though the inversion does look a bit weaker toward the
southern part of the CSRA and into the eastern Midlands and thus
an isolated shower or weak storm cannot be ruled out here
during the afternoon. Quiet weather should then prevail tonight
and into Monday morning outside of some possibly patchy fog
again, mainly toward the southern CSRA and eastern Midlands.

&&

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

- Showers and thunderstorms are possible on Monday and Tuesday,
  but overall coverage should be limited.

- Monday should be the hottest day of the week, with more
  seasonal temperatures Tuesday and Wednesday.

- Major Hurricane Erin will likely pass well to our east on
  Wednesday and may further limit convective coverage.

Synoptic Overview: Upper ridge axis should be centered near the
Ozarks at the start of the period, retreating west Tuesday into
Wednesday. This creates a weakness in the upper pattern,
allowing an trough to develop over the Northeastern United
States and pull Major Hurricane Erin north and eventually
northeast away from the region.

Monday should be the hottest day of the week. Highs in the
lower to mid 90s will combine with increasing moisture to
produce heat index values in the upper 90s to mid-100s, still
below Heat Advisory criteria. While the upper ridge should limit
convective coverage, CAMs are showing afternoon and evening
showers and thunderstorms, favoring the northern Midlands and
Pee Dee. A weak feature is expected to move in from the north
and is likely what the models are locking in on as a trigger.

Heights should lower on Tuesday in response to retreating upper
ridging. This should result in temperatures closer to seasonal
values and higher rain chances. Without a trigger in place,
convection should be more diurnally driven, dissipating quickly
with the loss of daytime heating. Major Hurricane Erin will make
its closest approach Tuesday Night into Wednesday but should
pass well to our east. Having said that, subsidence around the
tropical cyclone should suppress convection on Wednesday, though
this will depend on how close it gets to the United States.
Currently the NBM has lower PoPs on Wednesday likely in response
to Erin passing to our east. Besides potentially reducing
convection on Wednesday, Erin is not expected to have any
impacts to the NWS Columbia CWA.

&&

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

- More typical diurnally driven rain chances should return to
  end the week.

- Developing upper troughing should result in a cooling trend.

Upper troughing develops over the Eastern CONUS during the
extended, pushing Major Hurricane Erin out to sea. This should
result in a return to more typical rain chances with scattered
to numerous showers and thunderstorms each afternoon and
evening. Temperatures should be on a downward trend through the
period as the upper trough becomes more established, falling to
below normal values.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Patchy MVFR to IFR visibility restrictions overnight and into
Sunday morning before VFR conditions are expected the remainder
of the TAF period.

VFR conditions prevail at most TAF sites tonight outside of
some fog that has developed near AGS, leading it to bounce
between VFR and MVFR visibility restrictions. Guidance continues
to suggest some patchy fog will be possible tonight and thus I
have left mention of fog at all sites with MVFR restrictions,
but AGS/OGB, the typical fog prone sites, could come closer to
IFR restrictions. The main window for theses restrictions
appears to be between 09z and 13z before improving through the
morning. The recent HRRR and even NBM have shown possible areas
of stratus developing mainly near OGB, but confidence in this
leading to restrictions is fairly low at the moment and thus I
only added mention of FEW stratus into the TAF at this time. The
remainder of the TAF period sees VFR conditions as mostly clear
skies are expected outside of FEW to SCT cumulus during the
afternoon. Winds generally turn out of the northeast at 4-7 kts
before becoming a bit more easterly during the evening. In terms
of shower/storm chances, subsidence and a shot of drier air
should keep convective activity mostly at bay and thus even with
an isolated shower or weak storm possible, confidence in this
impacting any terminal is low.

EXTENDED AVIATION OUTLOOK...Summertime conditions expected with
daily convection each afternoon and brief periods of
fog/stratus possible each morning.

&&

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

&&

$$