799
FXUS62 KGSP 230605
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
205 AM EDT Thu May 23 2024

.SYNOPSIS...
Temperatures will remain several degrees above normal each day
through Tuesday of next week as humid subtropical air remains
over the Southeast. Chances for showers and thunderstorms increase
Thursday and will remain higher than normal for this time of year
into next week as well.

&&

.NEAR TERM /THROUGH TODAY/...
As of 200 AM EDT Thursday: Areas of thicker high clouds seems to
be delaying any fog development, as expected. The forecast area is
expected to remain dry thru daybreak, as ripples of weak synoptic
forcing will move overhead during the predawn hours, but will
encounter air too dry to support much, if any, precipitation. The
increasing cloud cover should help to inhibit fog formation,
including the mtn valleys, thru daybreak, while keeping lows in
the mid-60s, which is about 4 to 6 degrees above climatology.

Otherwise, we can expect more convective activity for Thursday aftn/
evening. Despite the fact that flat upper ridging will remain to our
south thru the near-term period, heights will fall on Thursday as a
cold front sags into the upper Tennessee Valley/Cumberland Plateau.
Afternoon profiles look much more favorable for convection with an
influx of colder air aloft helping to increase lapse rates. This in
turn should allow for the development of roughly 1000 t0 1500 J/kg
of sbCAPE across much of our area and possibly more over the I-77
corridor. Shear values should remain fairly weak (ie, <30 kts of
deep-layer shear) and low-level helicity will be minimal at best as
well. Thus, strong to severe downburst winds appear to be the main
threat for tomorrow with hail being more of a secondary threat.
Thus, SPC`s current day 2 Marginal Severe Risk highlighting both
wind and hail still appears pretty well placed.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
As of 215 PM Wed: A series of short waves will cross the area with
some sort of weak surface feature associated with the waves. This
will lead to mainly diurnal convection each day, with some lingering
showers possible during the overnight periods. Moderate instability
and bulk shear around 40 kts is possible on Friday, along with
decent sfc delta Theta-e values. A few severe storms will be
possible with some organization. With the good forcing in place,
expect widespread to numerous convective coverage of the mountains
and foothills and high end scattered coverage elsewhere. Temps will
be around 5 degrees above normal.

Coverage will not be as widespread on Saturday, but high end
moderate instability, along with 20 kts of shear and continued high
levels of sfc delta Theta-e values, along with increasing dCAPE may
lead to an uptick in severe thunderstorm chances. These would be
more of the pulse severe, damaging wind variety. Temps will be
around 10 degrees above normal.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 230 PM Wed: Unsettled weather expected into early next week as
the series of short waves continue to march across the area. Again,
there looks to be weak surface features until Monday when a more
organized cold front crosses the area. Expect precip chances to
steadily increase Sunday and Monday, although the convection should
be mainly diurnal. Some severe storms will be possible again
especially if the moderate instability and shear and dCAPE overlap.
Temps will be 5 to 10 degrees above normal.

Some lingering showers possible Tuesday even as the front moves
east, but thunder chances diminish. Temps will be up to 5 degrees
above normal. Dry high pressure expected on Wednesday with temps
near to slightly above normal.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Thunderstorm chances return to the area
today, as a cold front approaches from the NW. Plenty of high
clouds are expected to stream in from the west thru the morning,
which will limit fog potential. So expecting VFR to start the
day. Convection is expected to fire across the NC mountains early
in the aftn then spread/expand in coverage east late aftn thru
the evening. There is a lot of disagreement among the CAMs on
the timing of the convective initiation and tracking east. The
latest PROB30 groups for TS are based on the HRRR, which has some
run-to-run consistency, but confidence on the timing is below
average. Convection will exit to the east late evening thru the
overnight, leaving some debris mid and high clouds around, but some
clearing is expected before daybreak. With expected scattered to
numerous precip coverage, light winds and some clearing, may see
areas of fog develop late tonight, especially in the mountain
valleys and the NC Piedmont. Coverage of precip and subsequent
fog potential is expected to be lowest across the Upstate.

Outlook: Scattered to numerous showers and thunderstorms, along
with their associated flight restrictions, are expected again on
Friday. A more active pattern may persist thru early next week.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

SYNOPSIS...DEO
NEAR TERM...ARK/JPT
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK