-- Discussion containing changed information from previous version are highlighted. --
029
FXUS62 KGSP 220159
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
959 PM EDT Tue May 21 2024

.SYNOPSIS...
Warm high pressure will persist across the region through the
middle of the week with a few showers and storms possible each
afternoon over the mountains. Rain chances increase Thursday and
remain in the forecast each day through Tuesday.  Several weak waves
of low pressure will move from the lower Mississippi Valley to the
Carolinas.  Temperatures will remain above normal.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 955 pm EDT Tuesday: Mountain showers have dissipated with the
reversal of the diurnal heating cycle. Profiles are forecast to dry
out a bit overnight as a weak short wave trough translates east of
the CWA. Convective debris and/or stratocu will linger across the
mountains this evening, but will clear gradually after midnight as
the upper height gradient strengthens a bit, and residual moisture
is advected away.  A few hours of mountain stratus and valley fog
are depicted in most of the guidance, to clear out again quickly
after daybreak Wednesday.  Lows will drop to the lower 60s across
most of the area.  Another day of generally suppressed weather is
expected on Wednesday.  The lack of any discernible source of
organized lift paired with lapse rates at least as poor as today`s
should preclude much, if any, convection from occurring; instead, we
can expect another mostly dry and quiet day tomorrow.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 145 PM Tue: A series of short waves will cross the area in
generally westerly flow aloft. This will bring increasing chances of
mainly diurnal convection Thursday and Friday. That said, showers
may linger overnight, especially across the mountains. Instability
may rise into the moderate range Thursday, but a weakening warm nose
may linger keeping the better instability over the mountains, and
possibly into the I-85 corridor, especially if the forcing overcomes
the warm nose. Bulk shear will approach 50 knots, so a severe storm
or two will be possible if the instability and shear can overlap.
Temps will be around 5 degrees above normal.

Looks to be a better chance of realizing moderate sbCAPE Friday as
the warm nose appears to fully erode. Bulk shear drops back to
around 40 knots, but a few severe storms will be possible again
given the forcing and dCAPE values. Temps remain nearly steady.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 215 PM Tue: The active pattern continues as short waves move
through the generally westerly flow and across the area. With the
strongest wave moving in on Tuesday. This will least to continued
chances of diurnal convection, with lingering nocturnal showers as
weak surface features move through in association with the waves.
Too soon to tell if any of the days have a better severe storm
chance than the others, but they are possible. Also, heavy rainfall
chances will steadily increase as PW values increase with each wave.
Isolated flooding would be possible in areas that receive rounds of
heavy rainfall. Well above normal temps on Saturday drop a few
degrees by the end of the period.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Isolated mountain SHRA will dissipate through
mid-evening, with no impacts expected at the TAF sites. Otherwise,
VFR conditions are expected at most TAF sites through the period.
The only exception is expected to be at KAVL, where a brief period
of MVFR visby in BR is expected toward daybreak. Otherwise, light
and variable or calm winds are expected at most sites tonight, with
winds becoming SW at 5-10 kts late Wed morning. Convection (mainly
showers) are possible across the mountains again Wed afternoon, but
if anything, coverage is expected to be even more sparse than today.

Outlook: More numerous showers and thunderstorms, along with
associated flight restrictions, will return with a cold front late
Thursday into Friday. A more active pattern may persist through
early next week.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...JDL/MPR
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JDL