464
FXUS62 KCAE 190807
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
407 AM EDT Fri Jul 19 2024

.SYNOPSIS...
A frontal boundary will be stationary across the region for the
next several days with increased shower and thunderstorm
activity. Some locally heavy rainfall is possible which could
result in increasing levels in area rivers. Temperatures will be
near to slightly below through the middle of next week.

&&

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

- Patchy fog possible this morning.
- Another round of showers and thunderstorms this afternoon and
  evening.
- Locally heavy rainfall could lead to urban or flash flooding.
- Gusty winds possible with the stronger storms.

Through daybreak: The rainfall last evening left residual low-
level moisture across the area, which could lead to patchy fog
through about 8 or 9 am. Otherwise, any lingering light showers
are likely to dissipate by daybreak.

Today and Tonight: An larger scale upper trough continues to dig
into the Gulf states today into tonight, which puts the forecast
area under southwest flow. At the surface, a southwest to
northeast oriented frontal boundary is draped across the region.
With the upper flow essentially parallel to the front
orientation, don`t expect the boundary to move all that much
today. A shortwave is forecast to move across the area today,
which will likely act as an enhanced trigger for shower and
thunderstorm activity this afternoon into tonight. Overall
moisture is expected to be around 2" this morning, and
increasing to around 2.25" ahead of the incoming shortwave.
Forecast soundings also indicate long, skinny CAPE this
afternoon, which is conducive for heavy rainfall. A combination
of the high PWATs, heavy rainfall prone soundings, and the
potential for training cells this afternoon, there is a threat
for localized urban or flash flooding. WPC put the area under a
Slight Risk (category 2/4) for excessive rainfall for the
northern two thirds of the forecast area, which seems reasonable
given the atmospheric conditions mentioned above. In addition to
the heavy rain threat, today`s conditions could lead to isolated
instances of strong to potentially damaging winds due to precip
loading in the stronger thunderstorms today.

As far as temperatures go, there is a bit of uncertainty in the
afternoon highs today. Latest guidance has been trending
downward, which makes sense as we should see decent cloud
coverage. Thus, have adjusted highs down slightly to the upper
80s to lower 90s across the region. Overnight lows are forecast
to be around 70 tonight.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
- Afternoon and evening showers and thunderstorms likely this weekend

The area will be pinched between high pressure off the coast and
troughing over the middle of the country, inducing deep southwest
flow into the state. PWATs will remain around 2" over the weekend,
as a few weak shortwaves generate showers and thunderstorms across
the region in response to daytime heating. Without much wind shear,
storms will likely lack organization, but precip loading will still
elevate the threat for locally heavy rainfall and gusty winds. SPC
has extended a Marginal Risk for severe weather across the northern
CWA along the NC/SC border on Saturday, while WPC continues to
depict a Marginal Risk ERO through Sunday. With the convection and
associated clouds, temperatures are expected to be near to slightly
below normal with afternoon highs in the upper 80s to low 90s.

&&

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

-The pattern remains favorable for daily chances of afternoon
 and evening showers and thunderstorms

The upper level pattern will be a bit stagnant next week, with
strong ridging across the west, troughing across the central states
and slight ridging along the Atlantic coast. Shortwave energy is
progged to break off from the trough in the Plains and rotate across
the region, and may also originate from the GoM periodically. With
this setup, it is reasonable to expect daily chances for showers and
thunderstorms to continue. PWAT values should remain around 2", and
thus the potential for locally heavy rainfall and gusty winds due to
precip loading will continue. WPC maintains a Marginal Risk ERO for
portions of the area through at least Monday and Tuesday next week.
Daytime temperatures through the period will be near to slightly
below normal with afternoon highs in the upper 80s to low 90s each
day.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
MVFR to IFR conditions possible near daybreak before improving
to VFR for much of the TAF period.

Rainfall continues to diminish as of 06z, with light showers
being noted around OGB. Showers are also nearing AGS/DNL, but
they are diminishing and don`t think they will reach the
terminals. That said, a light shower cannot be completely ruled
out at AGS or DNL in the next few hours. Already seeing IFR cigs
in the region, and expect these ceilings to continue spreading
across the area. Low ceilings should affect all terminals early
this morning, with AGS/DNL having the highest probability of
seeing IFR ceilings. Visibility restrictions due to fog are
also possible at the terminals. The most likely timeframe for
stratus and fog is from 09z to 13z. Winds are anticipated to be
light and variable through around 14z or 15z, then become
southwest between 5 and 10 kts.


EXTENDED AVIATION OUTLOOK...Periods of showers and
thunderstorms may cause restrictions each day. In addition,
brief early morning restrictions may become more likely around
sunrise into the weekend.

&&

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

&&

$$