822
FXUS62 KCAE 181716
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
116 PM EDT Fri Jul 18 2025

.SYNOPSIS...
Hot and humid conditions remain in place through the upcoming
weekend and into early next week. Daily showers and thunderstorms
are possible, with increased convective coverage possible Monday and
Tuesday. Temperatures slowly return to normal and humidity
decreases by Tuesday and into the later part of the week.

&&

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

- Hot and humid this afternoon with scattered showers and a few
  thunderstorms possible.

Upper ridging continues to build into the forecast area this
afternoon allowing temperatures to climb into the 90s. Heat
indices at this hour range from the upper 90s to lower 100s and
are below advisory criteria at this time. Will monitor closely
to ensure this trend holds through peak heating. Convection has
once again outperformed model guidance this afternoon with
radar imagery showing scattered showers developing across much
of the Midlands. While no lightning has been detected yet, a few
thunderstorms cannot be ruled out given the ample moisture and
high CAPE values across the region, especially closer to the
coast. Any showers and thunderstorms that do develop, should
quickly diminish this evening with the loss of daytime heating.
Temperatures should peak in the mid to upper 90s this afternoon,
falling into the mid to upper 70s tonight.

&&

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

-Hot and humid conditions increase with heat indices of 100F-108F
likely each day.

-Isolated showers and thunderstorms expected during the afternoon
periods this weekend.

The forecast for the weekend remains on track as summertime is in
full swing. The strong upper high off the Atlantic coast continues
to churn and retrograde westward through Sunday night. At the
surface, high pressure to the south keeps moisture transport off to
the north on Saturday, but eventually sags southward in the CWA on
Sunday. Guidance shows an increase in PWATs by Saturday night with
upticks through the end of the short term. Values of 2.0-2.3
inches are likely, increasing the dewpoints and raising the heat
index (HI) through the weekend. Additionally, as height rises
occur with the slow building ridge, daytime temperatures
approach triple digits. Therefore, confidence is increasing for
HI values of 100-106 to be met at several locations within the
Midlands and Central Savannah River Area. There are also pockets
of 108-109 HI, but coverage is spotty. At this time, given the
narrow coverage of these HI values, will hold off on any Heat
Advisory. Along with the hot and humid conditions, subsidence
aloft and the location of the high pressure reduces shower and
thunderstorm chances for Saturday to slight chance (15-30%),
with the Pee Dee and Charlotte Metro areas having the better
chances. By Sunday, increased coverage of showers and
thunderstorms is possible as the CWA becomes wedged between high
pressure to the north and south, allowing for more westerly
flow to filter in. Given the light flow aloft and modest
instability at this surface, this should lead to more scattered
shower and thunderstorm chances (25-40%) on Sunday across the
entire area.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Key message(s):

-Hot and humid conditions persist into early next week with some
relief after Tuesday.

-Shower and thunderstorm activity increases through Tuesday before
becoming more typical for summertime.

By Monday, the pattern remains on the hot and humid track. An
amplifying ridge out west migrates eastward, increasing heights
across the southeast. Monday looks to be under the influence of the
high pressure, providing an increase in chances for showers and
thunderstorms as embedded shortwaves riding along the eastern edge
of the high slide across the area. There is still some uncertainty
as to where the ridge axis sets up and how far east the eastern edge
extends, but either way, scattered to widespread convective chances
are there for Monday and into Tuesday. By midweek, a weak trough off
the East Coast slowly moves out, allowing for another area of high
pressure at the surface to build into the northeast. Guidance at
this time shows a decrease in moisture advection as NE surface flow
could filter in drier air. This would be a mild relief to the hot
and humid conditions and bring temperatures down to more normal
values for July through the end of the extended period. With the
drier air from the northeast and the ridge axis moving over the
southeast, subsidence aloft looks to reduce the daily diurnally
driven convection into the slight chance range (15-35%) Wednesday
through the end of the forecast, which is more typical for the area
during this time.

&&

.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
Brief Restrictions from Scattered Showers Possible this
Afternoon....

SCT cumulus clouds have continued to develop over the last few
hours with radar now showing scattered showers and a few
thunderstorms across the region. Brief restrictions are
possible at any terminal this afternoon should a shower or
thunderstorm pass over. Will add a PROB30 to CAE/CUB/OGB for
thunderstorm potential during the next few hours based on
recent satellite and radar trends. Any convective activity
should diminish around 00Z with light winds and passing high
clouds expected tonight. The potential for low clouds and fog
near daybreak appears low at this time. Renewed shower activity
is possible near the end of the current TAF period.

EXTENDED AVIATION OUTLOOK...Seasonal restrictions continue with
isolated 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.

&&

$$