751
FXUS62 KCAE 171755
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
155 PM EDT Thu Jul 17 2025

.SYNOPSIS...
Upper level ridging will be in control of our weather through the
upcoming weekend bringing above normal daytime temperatures and high
humidity. Despite the presence of ridging, diurnally driven showers
and thunderstorms will be possible each day. This pattern breaks
down Sunday into Monday with an increase in moisture and a decrease
in temperature for the mid-week period.

&&

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

- Typical July afternoon with isolated to scattered showers and
  a few thunderstorms.

Scattered cumulus have become more developed across portions of
the FA this afternoon with scattered showers passing through the
eastern half of the CWA. A few thunderstorms have also
developed, mainly in northern Lancaster County and east of I-95.
While upper ridging continues to build over the region today,
the region remains in a typical summertime surface pattern with
a warm, moist air mass being advected from the Gulf along the
edge of the Bermuda high. Not expecting widespread coverage for
the rest of today but increased PoPs from the NBM based on
convective trends. Any activity should quickly diminish this
evening with the loss of daytime heating with tranquil weather
anticipated for the overnight period. Temperatures are on track
to reach the lower to mid 90s this afternoon, falling into the
mid-70s by daybreak Friday.

&&

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

- Heat and humidity builds into the weekend with heat indices
exceeding 105F each day.

- Isolated to scattered showers and storms expected mainly during
the afternoon each day.

The Bermuda high that has been anchored off the Southeast U.S. Coast
will begin to build westward with the center of the anticyclone
passing to our south across FL and along the northern Gulf coast.
Despite the close proximity of the high to our region, the surface
pattern is more reflective of troughing over the Mid-Atlantic and
Carolinas as the tail end of a surface boundary associated with low
pressure over eastern Canada gets left behind. The trough axis will
likely be positioned just to our west owing to the influence of
diurnal-reinforced lee trough development closer to the Blue Ridge.

The heat and humidity will become increasingly oppressive as a
result of the Bermuda ridge building westward. Peak heat indices
between 103-107F should be commonplace on Friday. There is some
potential for a few spots in the CSRA and Midlands to reach Heat
Advisory criteria of 108F, but the latest experimental probabilistic
guidance from the NBM shows probabilities of heat indices exceeding
advisory criteria were 15 percent or less. Opted to not issue any
heat headlines for Friday with probabilities this low. Probabilities
increase Saturday and Sunday while the deterministic NBM indicates a
more widespread max heat indices of 108-112F across most of the area
both Saturday and Sunday.

Diurnal showers and storms can be expected each afternoon but
coverage/organization should generally be limited owing to a lack of
large-scale lift and even some residual subsidence underneath the
ridge. Forecast PoPs each afternoon peak between 20-30 percent. A
greater convection potential is expected just to the north and west
of the CWA - closer to the surface trough and within a favorable
pattern for MCSs to track along the northern periphery of the upper
ridge. Did not see a need to deviate much from the NBM.


&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...

Key message(s):

- Hot and muggy pattern will continue into next week. The most
oppressive conditions are expected Monday with heat indices
exceeding 110 degrees.

- Showers and storms will increase in coverage in the early week.


The high will continue to retrograde westward toward the lower
Mississippi Valley early in the week. Meanwhile, the upper ridge
will break down on Monday in response to a trough passing across the
Northeast U.S. This will allow for the favorable ring-of-fire
pattern to shift southward toward our area as MCSs track within the
belt of stronger westerlies that reside along the northeastern
periphery of the ridge. PoPs increase to likely for Monday and high
chance for the middle of the week.

The heat and humidity looks to peak on Monday with forecast heat
indices approaching Extreme Heat Watch/Warning threshold. A
potential wrench in the forecast is if one of these MCS reach the
area early enough in the day to preclude us from reaching the full
potential.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Monitoring Passing Showers near the Terminals this Afternoon....

Scattered cumulus have become more developed across portions of
the FA this afternoon with scattered showers passing near
CAE/CUB/OGB. Cannot rule out a shower or thunderstorm at any TAF
site this afternoon, especially at the previously mentioned TAF
sites where a PROB30 has been added. Any shower or thunderstorm
could produce brief restrictions at the terminals, so will
monitor and update the forecasts as needed. Any convection
should quickly dissipate after 00Z due to the loss of daytime
heating, with tranquil weather expected for the remainder of the
TAF period. While areas of low clouds and/or stratus cannot be
ruled out around daybreak, confidence is not high enough for
inclusion in the TAFs. Showers and thunderstorms may redevelop
near the terminals towards the end of the current TAF period on
Friday afternoon.

EXTENDED AVIATION OUTLOOK...Typical seasonal restrictions
continue with daily convection and patchy early morning
fog/stratus possible through Sunday. Rain chances increase early
next week ahead of an approaching surface boundary.

&&

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

&&

$$