596
FXUS62 KCAE 121850
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
250 PM EDT Mon Aug 12 2024

.SYNOPSIS...
Scattered showers and thunderstorms expected each afternoon
through tomorrow. Then drier air moves into the region allowing
for a few slightly cooler days with only isolated showers and
thunderstorms. Moisture returns to the region late this week and
into the weekend as a frontal system moves into the eastern US.

&&

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

- Showers and thunderstorms expected across the eastern half of
  the forecast area this afternoon.

Cloud cover held on a bit longer than anticipated this morning
into early afternoon, but now we`re seeing the typical afternoon
cumulus field developing across the region. Expect showers and
thunderstorms to also develop once again this afternoon due to a
lingering surface boundary across the region and a weak
shortwave moving through the area. There could be an isolated
instance of flash flooding, but storm motion is forecast to be
bit faster than the past couple of days. So, don`t think the
risk is as high, however. MLCAPE is currently around 2000 J/kg,
but the DCAPE is less than 1000 J/kg. Therefore, the threat for
a severe storm is low as well. I expect activity to wind down
shortly after daytime heating is done this evening as the
shortwave should be east of our forecast area by then. With
lingering low-level moisture again tonight, anticipate fog and
stratus to be possible again. Much of this will depend on
whether or not there will be high clouds overnight. Lows are
expected to be in the lower to mid 70s tonight.

&&

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

- Damaging wind gusts possible Tuesday afternoon and evening

Upper level pattern will gradually amplify through the short
term with the trough axis digging slightly over the east coast.
As the trough digs on Tuesday afternoon there will also be a
short wave moving north of the area which will be a focus for
convection Tuesday afternoon and evening. Instability will be
moderate to strong with pwat ranging between 1.8 and 2.0 inches.
Although the exact track of the short wave maintains some
uncertainty expect scattered showers and thunderstorms through
the afternoon and into the evening hours. There will be
potential for locally heavy rainfall again expect cell movement
to be sufficient to keep the threat low. The severe threat will
be focused on winds as DCAPE values will be increasing to around
1000 J/Kg and this agrees with the SPC marginal risk of severe
thunderstorms. On Wednesday the trough will dig slightly and
slide to the coast with a weak surface boundary over the
southeastern Midlands and southern CSRA. This will keep a low
chance of showers and thunderstorms mainly along and south of
I-20 with slight chances elsewhere. Slightly drier air will also
be working into the area which will lower the heavy rainfall
threat. Mid level lapse rates will also be less than 5.0 C/Km so
potential for severe thunderstorms will also be low. High
temperatures will be in the mid 80s to low 90s Tuesday and
slightly cooler on Wednesday with mid to upper 80s. Overnight
lows will be in the upper 60s to low 70s Tuesday night with mid
to upper 60s Wednesday night.

&&

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

- Drier air moves into the region mid to late this week
- A frontal system may approach the area Friday into the weekend

The upper level pattern will continue to amplify through the
long term with a low pressure system moving into the Great Lakes
Thursday night and slowly moving through the Great Lakes over
the weekend an into New England on Monday. This will push a cold
front through the region Friday into Saturday with drier
conditions expected to move in behind the front. Overall this
will keep slight chance to chance pops in the forecast each day
with the highest pops Friday night through Saturday as the front
crosses the region. High temperatures through the long term will
be near to slightly below normal.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Generally VFR conditions expected outside of brief restrictions
in diurnally driven thunderstorms and early morning stratus/fog.

Isolated to scattered showers and thunderstorms are expected to
develop this afternoon across the area, mainly for the eastern
portions of the forecast area. Confidence is low (<20%) that
any of the terminals will see showers nearby. so have kept
mention of VCSH or RA out of the TAFs for the time being.
Overnight, there is a good chance (>50%) for stratus and/or fog
to develop late once again. However, this formation is partially
dependent on whether high clouds linger overnight. In general,
winds are expected to be light around 5-8 kts.


EXTENDED AVIATION OUTLOOK...Afternoon and evening convection
and associate restrictions will be possible through Friday.
Early morning fog and stratus could occur, especially at fog-
prone AGS/OGB.

&&

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

&&

$$