305
FXUS62 KCAE 311756
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
156 PM EDT Thu Jul 31 2025

.SYNOPSIS...
Heat and humidity continues into the end of the week with
widespread shower-storms expected, mainly Friday. This heat
spell is expected to break as a cold front is forecast to bring
cooler conditions by the weekend. Chances for the typical
afternoon and evening showers and thunderstorms continue each
day through the forecast period.

&&

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

- Hot and humid with scattered storms this afternoon and into
  this evening.

- Heat Advisory in effect until 8pm along and south of I-20.

Muggy conditions are taking shape early this afternoon with
dewpoints in the mid to upper 70s and temperatures approaching
the low to mid 90s, leading to heat indices between 105-110F
mainly along and south of I-20. Due to this, a Heat Advisory has
been issued for this region, including the Columbia Metro until
8pm.

Some weak surface troughing is evident ahead of the cold front
that is entering Kentucky and Tennessee and this is helping in
getting some showers/storms started toward the upstate of SC and
GA. Some dry air aloft entering the southern CSRA and into the
eastern Midlands is evident in both GOES PWAT`s and WV imagery.
PWAT`s generally remain around 2.1-2.2" and is a bit lower
toward the southern CSRA, near 2". The combination of this dry
air and the approaching surface front (and the upper trough in
the Great Lakes) brings an environment with seasonably high
MLCAPE, but DCAPE that is increased across the CSRA and into the
eastern Midlands, where mid level dry air is located. The rest
of the FA has fairly saturated profiles and thus DCAPE is on the
lower end. Steering flow has also increased a bit today (around
15-18 kts) and thus the expectation is isolated to scattered
convection starting late in the afternoon and into this evening
may produce heavy rain, frequent lightning, and possibly some
damaging wind gusts. As has been seen the past couple days,
some isolated showers or weak storms could carry into the
overnight hours as increased low level moisture remains and
greater synoptic forcing slowly works its way in.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Key message(s):

- Hot conditions continue with ample moisture ahead of an
  approaching trough.

- Strong-severe thunderstorms possible in the afternoon along
  with a flash flood threat.

Well advertised cold front will be making its way towards the
region on Friday, aided by a trough pushing into the eastern
CONUS. This trough is clear in WV imagery across the Great
Lakes, pushing southeastward and pushing a 99th percentile
surface high into the OH Valley as well. Ahead of this, high PWs
are forecast to pool along and ahead of the approaching front,
with 2"-2.3" PWs expected to remain across the area tomorrow.
Guidance shows a dry morning, but convection is forecast to
erupt pretty quickly by midday. Given high dewpoints and some
slightly drier mid-level air, we look to have a pretty robust
downburst environment present across the FA tomorrow afternoon.
The HRRR (as is typical) is too aggressive with dewpoint mixing
but other CAMs such as the RRFS and REFS are aggressive and
match up with the coverage that the global models show.

RAP soundings tomorrow afternoon are really robust for severe
downbursts, with TEI >25, DCAPE >800, and MLCAPE >3000 j/kg.
When removing the over-mixed HRRR from the REFS mean soundings,
the parameters are fairly similar. As such, we are expecting
strong to severe thunderstorms with the convection tomorrow
afternoon and evening. The primary threat will be damaging
downbursts featuring winds of 60-70 mph and copious lightning.
Given high PWs and strong forcing, flash flooding is also a
threat. We may end up being close to Heat Advisory criteria by
the afternoon but it is difficult to know whether we will need
one or not given the uncertainty of CI. The timing of that will
likely modulate the need for one, which is something the
midnight shift will have a better idea of. Highs should end up
in the mid 90s. Overnight, expect convection to continue for
much of the night as we maintain some level of instability and
forcing as the front pushes through. Lows should be in the low
70s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Key message(s):

- Cooler temps are likely as we move through the weekend as a
  notable front slides southward into the area.

This weekend looks pretty awesome. The front will slowly sag
through the area on Saturday, ushering in a much cooler airmass.
Additionally, widespread cloud cover is forecast to hang around
the region during the afternoon hours. Showers and storms are
again possible both days, especially along and south of I20 that
will be closer to the surface front. As a result, we are
looking at temperatures 8F-15F below normal for afternoon highs.
It is a welcome reprieve from the heat that we have had the
last week or so. By early next week, the surface ridging is
forecast to slowly weaken, but temps likely will remain a few
degrees below normal as rain chances increase in response to a
slow moving trough across the Mid MS Valley.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Isolated to scattered storms could bring periods of
restrictions this afternoon and into the evening before patchy
stratus is possible early Friday morning, though confidence in
restrictions is not high at the moment.

SCT cumulus is developing this afternoon with a couple more
agitated cumulus starting to appear north of the CAE/CUB. Winds
are between 6- 10 kts out of the southwest and should continue
for the remainder of the afternoon. There is some uncertainty in
the timing of potential restrictions from convection as recent
high-res models have pushed back the main window after 20-22z,
though some development earlier is possible. To account for this
I added mention of VCSH at 20z for the TAF sites and a TEMPO
group from 21z to 01z. Some isolated activity may then linger
into the overnight hours like has been seen the past couple
nights, but confidence in restrictions from this is low. With
abundant low level moisture and nearly calm winds, think some
patchy stratus is likely again tonight and into Friday morning
even though model guidance is not as confident. There is less
confidence in restrictions at any given TAF site and thus for
now I have included mention of FEW to SCT stratus into Friday
morning at each site. Winds then pick back up out of the
southwest to south late Friday morning with more cumulus
expected to develop.

EXTENDED AVIATION OUTLOOK...Afternoon convection could bring
brief periods of restrictions this weekend, with coverage
currently looking to be greatest on Friday at this time. With
increasing moisture, cannot rule out possible predawn stratus or
fog. Increasing confidence for more widespread stratus over the
weekend behind a cold front.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory until 8 PM EDT this evening for SCZ022-027>031-
     035-037-038-041-135>137.
GA...Heat Advisory until 8 PM EDT this evening for GAZ063>065-077.

&&

$$