Area Forecast Discussion
Issued by NWS Columbia, SC

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305
FXUS62 KCAE 181735
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
135 PM EDT Tue Aug 18 2026

.WHAT HAS CHANGED...
Little change to the overall forecast. Aviation discussion
updated for 18z.

&&

.KEY MESSAGES...
- 1. Above average temperatures continue through the end
  of the week.

- 2. Storm coverage will be limited again today, with increasing
  potential late week into the weekend.

&&

.DISCUSSION...
KEY MESSAGE 1: Above average temperatures continue through the end
of the week.

A Heat Advisory continues through until 8pm today along and south of
I-20 with heat indices expected to rise to around 108F. Temperatures
will likely be similar each day through the end of the week with the
interquartile range of blended guidance showing limited spread
leading to relatively high confidence in highs in the mid to upper
90s each day through Friday. A weak front moving through the area
today will do little to affect temperatures but will push in some
slightly drier air, allowing for increased drier air mixing to the
surface. Dew points as a result will likely dip to or below 70F
during the afternoon today, tomorrow and Thursday. This will likely
still lead to heat indices between 100F to 105F, although keep us
below Heat Advisory criteria. Moisture increases Friday as the ridge
begins to break down. A decrease in temperatures would be offset by
the moisture increase, although higher chances for showers and
storms will also limit temperatures. More seasonable conditions
expected for the weekend, finally providing us a break from the
oppressive heat.

KEY MESSAGE 2: Storm coverage will be limited again today, with
increasing potential late week into the weekend.

A capping inversion similar to yesterday is expected again today
across the area, which should limit convection despite weak
convergence along a surface front. However, given the heat and
humidity in place a stray shower or thunderstorm cannot be
completely ruled out, especially closer to the Coastal Plain.
Scattered afternoon thunderstorms will be possible each afternoon
Wednesday and Thursday, favoring the eastern portion of the forecast
area where moisture will be highest and the sea breeze and stalled
weak surface boundary will provide some forcing. As the upper ridge
breaks down Friday and Saturday, more widespread showers and storms
expected.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR conditions are expected through the TAF period with a very
low chance for spotty shower or storm this afternoon.

FEW to SCT cumulus are developing this afternoon as light winds
out of the northwest to north-northwest develop. These
conditions likely continue the remainder of the day with a
stray shower/storm possible, but this is looking rather
unlikely. Tonight, passing cirrus will be possible again with
light and variable winds as a 20-25 kt LLJ develops. Winds
likely become a bit more northerly to northeasterly after
14-16z Wednesday, but remain light. VFR conditions likely
persist to the end of the TAF period with SCT cumulus slowly
developing again Wednesday afternoon.

EXTENDED AVIATION OUTLOOK...Diurnal chances for thunderstorms
increase through the week, peaking this weekend.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory until 8 PM EDT this evening for SCZ016-022-
     027>031-035-037-038-041-135>137.
GA...Heat Advisory until 8 PM EDT this evening for GAZ064-065-077.

&&

$$

DISCUSSION...96
AVIATION...DH