649
FXUS62 KCAE 201540
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1140 AM EDT Sat Jul 20 2024

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

&&

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

- A couple rounds of scattered showers and storms today.
- A few thunderstorms may become strong to severe with gusty
  winds as the primary severe hazard.

Deep southwesterly flow remains across the forecast area today,
continuing to support deep layer moisture over the forecast area
with satellite derived PWAT estimates around 2 inches. A subtle
shortwave is currently moving through the CSRA which is
generating showers, although limited instability so far today
has prevented thunderstorm development with LightningCast
showing low probabilities over the next hour at least. HiRes
guidance is struggling to resolve this first batch of showers as
the consensus was a weakening trend far too soon. Appears that
the showers will continue northeast into the Midlands early this
afternoon, followed by a break. Then with another shortwave
moving currently generating convection in southern Georgia,
expect another round of convection, with higher chances for
thunderstorms this evening. Current tracking puts this activity
moving into the Augusta area between 6 and 7pm not a bit earlier from
HiRes model timing and then moving into the Columbia area an
hour or two later. There will likely be sufficient time between
this first batch of showers and then activity this evening to
achieve at least moderate destabilization. A marginal risk for
severe weather remains in place across the area with forecast
soundings indicating higher low level theta-e difference and
stronger deep layer shear, indicating more of a damaging wind
gust threat and more organized multi-cellular clusters compared
to yesterday. Does look like storms should be moving quicker
compared to yesterday which should minimize the flooding threat
but any storms that do develop will have high rain rates in the
high moisture environment. Temperatures continue to be near
seasonal average in the upper 80s to low 90s for highs and low
70s for lows.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
Key Message(s):

-Stagnant pattern persists with a continued potential for heavy rainfall.

A frontal boundary will remain stalled across the Southeast
U.S. early next week. A weak upper level trough remains over the
mid Mississippi River Valley with disturbances moving through a
southwest flow aloft over The Midlands and CSRA. The lower
levels of the atmosphere remain exceptionally moist with
precipitable water levels in excess of two inches. The stalled
boundary as well as the sea breeze front will be the primary
triggers for diurnal convection with the weak upper level
disturbances enhancing the coverage. Locally heavy rainfall and
flash flooding remain the primary hazards as well as isolated
wet microbursts.

&&

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

-Subtle pattern change with a trend toward less rainfall and warmer
 temperatures.

There may be a subtle shift in an otherwise stagnant weather pattern
later next week. The ensembles as well as the deterministic medium
range models depict a retrogression of the weak upper level trough
and perhaps even the filling in of this feature. In addition the
Bermuda high builds westward into the Southeast U.S. This would
shift the highest chances of precipitation west of the Appalachians
and allow for warmer high temperatures. Will stick with a
persistence forecast until the model blend picks up on the subtle
pattern shift.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
Areas of low clouds continue to move through the region early
this morning causing periodic restrictions, especially at OGB.
The low ceilings could persist at the terminals during the next
hour or two, gradually lifting and transitioning to scattered
cumulus decks by midday. Scattered showers and thunderstorms are
expected to develop this afternoon and evening, likely
resulting in brief restrictions as they pass over the terminals.
Any convection should wind down after sunset followed by a
possible return of low stratus late towards daybreak Sunday.

EXTENDED AVIATION OUTLOOK...Thunderstorms likely each day and
may cause brief restrictions. Abundant low level moisture may
cause early morning restrictions through mid-week.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...