894
FXUS62 KCAE 040559
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
159 AM EDT Tue Jun 4 2024

.SYNOPSIS...
Moisture increases across the Southeast through mid week leading
to scattered convection each afternoon. A cold front will move
across the Southeast late in the week increasing chances for
showers and thunderstorms, and potentially severe weather. Drier
air follows the front for late this week and into the weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Lowering sun angle combined with a stabilizing atmosphere from
convection this afternoon and this morning are resulting in
diminishing coverage of convection. There are numerous
boundaries across the forecast area from outflows from
convective cells so expect a few new cells to develop over the
next couple of hours where boundaries collide as well as ares
which were able to clear and receive some heating in the
northern CSRA and southwestern Midlands.

Overnight the upper level ridge over the area will continue
moving slowly eastward and be along the coast by daybreak. Drier
air noted on current WV imagery will also be moving over the
area and instability will be weak at best. Have kept slight
chance pops in the northern CSRA and western Midlands which will
be closer to upstream convection expected for Tuesday with the
remainder of the area dry. With partly cloudy skies for the
majority of tonight lows will be in the mid 60s for most
locations.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
During the early morning, shortwave ridging will be moving
offshore.  This may allow a series of shortwaves to move across
the forecast area (FA) Wednesday. A weak shortwave in the
morning could promote showers moving into the area from the west
similar to the previous morning. Showers would be light and
likely isolated since the shortwave is weak and muCAPE values
around or less than 250 J/kg.

Convective activity will increase mid day and into the afternoon
as daytime heating leads to a conditionally unstable airmass.
Mean GEFS PWAT values are around 125% of normal which would
promote deep, moist convection. There will also be upper level
support as a shortwave leads to negative vorticity advection
over the area late in the day. At the surface, outflow
boundaries from any morning convection and the sea-breeze
boundary in the afternoon should trigger additional development
into the evening and even overnight before the shortwave finally
pushes east. Temperatures will be near normal.

The threat of severe weather Tuesday afternoon is low. Lapse
rates will be slightly steeper than the previous day. Median
sbCAPE values from the SPC SREF are around 1000 J/kg which will
be enough to support thunderstorms but marginal for severe
weather. Deep layer shear is weak, pointing to pulse-type
convection and a saturated vertical profile also point to
limited severe potential.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Mean 500mb heights from global ensembles have been persistent
digging an upper level trough from northern Plains into the
Great  Lakes region mid-week then closing off as it moves into
the eastern US late-week. This will drive a cold front into the
Southeast from late Thursday into Friday. As the front
approaches, we will see moisture and SW flow increase on
Wednesday and Thursday. PWAT values will likely be above 1.75
inches. 25 percent of LREF members show PWAT values at or above
2 inches at some point during this time frame. Increased warm,
moist advection and convergence ahead of the front will support
scattered to numerous showers and thunderstorms Wednesday and
Thursday. Deep layer shear increases to near 30 kts which
indicates some potential for stronger or severe storms,
particularly Thursday. The front should work through the FA by
Friday or sooner. Dry, downslope flow behind the front will
allow temperatures to remain near normal into the weekend.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR conditions generally expected over the 24 hr forecast
period.

Convective debris clouds lingering across the CSRA but eventually
should thin out through sunrise. A 25 knot low level jet should
limit fog potential through sunrise. Expecting another round of
diurnal convection today with a bit better coverage due to the
arrival of some upper level energy in the form of a weak shortwave
during peak heating. Winds should pick up from the southwest around
5 to 8 knots by 15z. Scattered afternoon storms may impact terminals
but timing and location of storms uncertain at this time. Convective
debris clouds through the evening may give way to some cig
restrictions late tonight due to abundant low level moisture.

EXTENDED AVIATION OUTLOOK...Scattered afternoon and evening
showers and thunderstorms through Friday with intermittent
CIG/VSBY restrictions possible.

&&

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

&&

$$