652
FXUS62 KCAE 031759
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
159 PM EDT Mon Jun 3 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 /THROUGH TONIGHT/...
An area of showers west of Columbia which brought light accums to a
few locations this morning has diminished. To the east,
abundant sunshine has led to quick development of showers and a
few lightning strikes. These showers seem to be moving into an
area with 1000-1500 J/kg of SBCAPE with little to no cap, PW
values around 1.5"-1.7", and strong low level lapse rates.
Thankfully, DCAPE values west of I-95 are generally less than 800
J/kg and so these showers are probably not producing much wind
at the surface. CAMs have not been initializing or handling this
convection well, so there is very low confidence on how things
may evolve this afternoon. In general, with dewpoints in the mid
to upper 60s it does seem reasonable to expect isolated to
scattered showers and storms into this evening, likely moving
from west to east. Severe potential is low with wind shear less
than 30 kts. Upper ridging moving in from the west may also act
to suppress more widespread convective development. We`ll have
to keep an eye out for any cell/outflow mergers as the sea
breeze moves inland later this afternoon, particularly for our
eastern Midlands counties.

Temperatures are currently in the upper 70s to mid 80s, and
should peak similar to yesterday in the mid to upper 80s. The
caveat will be if any debris/convective clouds will hinder max
heating potential. Tonight, any lingering convection should
dissipate before midnight with the loss of heating and
stabilization of the atmosphere. Overnight lows expected to be
mild with lows in the mid 60s.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
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 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 /18Z MONDAY THROUGH SATURDAY/...
Mainly VFR conditions expected through the TAF period.

SCT-BKN clouds mainly AOA 4-6kft MSL. ISOLD-SCT -SHRA and ISOLD
-TSRA this afternoon and evening with low confidence of impacts at
any one terminal. As such, cannot rule out brief CIG/VSBY
restrictions with the heavier showers/storms. SFC winds SWLY around
5 to 8 knots through the afternoon, tapering off to SLY less than 5
kts overnight. Precip should decrease markedly after sunset, then
redevelop Tuesday with the daytime heating. Winds on Tuesday
SLY/SWLY 4-8 kts.

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

&&

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

&&

$$