511
FXUS62 KCAE 160722
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
322 AM EDT Tue Jul 16 2024

.SYNOPSIS...
Shower and thunderstorm chances increase during the mid-week
period as a trough sets up over the eastern US and a cold front
approaches from the northwest. This boundary is expected to stall
over the Southeastern US during the late week period keeping
elevated rain chances in the forecast. A gradual decrease in daytime
temperatures can be expected through Friday.

&&

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

- Hot and humid conditions once again with heat indices of 105+,
resulting in a Heat Advisory for the eastern central and  eastern
Midlands.
- Isolated to scattered thunderstorms possible once again this
afternoon and evening, with some strong winds possible.

Upper air analysis indicates a large scale trough over the Upper
Midwest, which is working to inch its way southward today. An
elongated trough within the main flow is also currently located to
our west, which is allowing for southwest flow to move into the area
today. The sagging larger scale trough is expected to keep
temperatures a few degrees cooler than yesterday, but still be in
the upper 90s. The southwest flow aloft brings in additional
moisture to the region, resulting in dew points in the 70s. As a
result, many locations will likely see heat indices around 105 or
higher. The highest heat indices are again over the central and
eastern Midlands, so have hoisted a Heat Advisory for the afternoon
and early evening. Overnight lows are forecast to be similar to the
past few nights, with lows generally in the mid 70s.

Isolated to scattered showers and thunderstorms are expected to
develop this afternoon and continue into the evening. Coverage-wise,
anticipating similar coverage to yesterday. Instability values are
forecast to be in the 1500-2000 J/kg range. Shear remains to be on
the lower side due to the lack of a boundary in the area. However,
forecast soundings do support a low (5-10%) chance of strong to
damaging wind gusts in the strongest storms due to increased DCAPE
this afternoon. Some of the machine learning guidance is also
picking up on this possibility. After sunset, activity is expected
to wane.

&&

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

- Shower and thunderstorm chances increase through the period
- Hot and humid conditions continue both days

High pressure anchored offshore keeps continuous southwest flow and
a steady stream of moisture into the region. PW will linger near 2",
while temperatures peak in the mid and upper 90s. Dewpoints in the
70s will yield heat indices in the low 100s, but should remain under
heat advisory criteria. A front will slowly near the region from the
northwest on Wednesday as a trough sags south from the Great Lakes.
This will result in increasing shower and thunderstorm activity.
Localized heavy rainfall and areas of flooding look to be possible
due to slow moving and training storms in a saturated environment.
Similar conditions occur Thursday, though better organized storms
are possible as the front crosses the region with better upper
dynamics. Overnight lows remain mild both nights, with temperatures
in the mid 70s Wednesday night and low 70s Thursday night in wake
of the front.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Key Message(s):

- Copious moisture will lead to scattered to numerous showers and
thunderstorms each day.

PWATs remain around 2" in the extended, with scattered to numerous
showers and thunderstorms expected each day as the aforementioned
frontal boundary gets hung up across the southeast. A few
thunderstorms could become strong and produce gusty winds in
addition to the heavy rain threat that will persist. Temperatures
should also cool off into the low 90s with the addition of cloud
cover due to convection in conjunction with the breakdown of the
upper ridge/troughing across the Deep South. A few robust shortwaves
will move through the southwest flow over the weekend into early
next week, inducing a few more active weather periods. However, it
is a bit too soon to pinpoint exactly when this will occur.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR conditions generally expected through the TAF period.

Some scattered mid-level clouds are moving through the forecast area
this morning, but expecting these to stay in the VFR category. Due
to the rainfall, AGS could see some MVFR visibilities early this
morning if cloud cover remains limited. Otherwise, isolated to
scattered thunderstorm activity is expected to develop this
afternoon, but confidence in where these storms form today is
too low to include in the TAFs. Winds are expected to pick up to
around 10 kts out of the southwest after about 15z.

EXTENDED AVIATION OUTLOOK...Typical summertime afternoon
showers and thunderstorms may cause periodic restrictions each
day with abundant moisture causing possible, brief early morning
restrictions around sunrise.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory from noon today to 7 PM EDT this evening for
     SCZ016-022-027>029-031-037-038-041-115-116-135>137.
GA...None.

&&

$$