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006
FXUS62 KGSP 270700
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
300 AM EDT Mon May 27 2024

.SYNOPSIS...
Strong to severe thunderstorms early this morning with another round
possible Monday afternoon with a cold front. Cooler and drier
conditions return Tuesday through Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 244 AM EDT Monday: As we await the arrival of the line of
thunderstorms coming off the Cumberland Plateau at 230 AM, some
renewed shower activity was noted over the NW Piedmont where some
residual lift was present, and over the SW upslope areas. Will
update the precip probs to account for this. Speaking of the
upstream convection, the current movement of the line would have
it reaching the NC/TN border right around 08Z. However, the line is
broken and is more parallel to the shear vector than the part of the
line in eastern KY, which suggests less of a threat for widespread
wind damage. It might actually be the rogue thunderstorms ahead
of the line in northern AL that could be more of a problem if they
get incorporated into the line and then reach southwest NC. As for
warnings, we will begin by taking our cues from the MRX office
and then go from there. Still no inkling of impending weather
watches, but that can change quickly. Available buoyancy is the
main limiting factor across the NC mountains, with maybe 1000-1500
J/kg of most-unstable CAPE and maybe 500-1000 J/kg of sfc-based
CAPE that was limited to the southern mountains. This is all to say
the trend is toward the underwhelming, but let`s not let our guard
down until the line actually hits the mtns and falls apart in its
attempt to cross the divide. Precip probs were adjusted accordingly.

For today, the plan remains to gradually diminish the remnant of
the QLCS east of the mtns after daybreak, with the best thunder
chances and higher precip probs over northeast GA and the Savannah
R basin, where the deeper convection can reach without crossing the
mtns. In the wake of the QLCS remnants, expect widespread debris
cloudiness and lingering light rain. Indications are that the
precip and clouds will break up early enough in the day to allow
some air mass recovery. The RAP still shows muCAPE climbing back up
to the 2500-3000 J/kg range in the late afternoon, along with 30-35
kt of deep layer/cloud layer shear. If that is indeed the case,
then scattered thunderstorms could develop mainly east of the mtns,
and pose a risk of damaging wind gusts and large hail. Coverage on
the CAMs is relatively widely scattered, but a few severe storms
will not be ruled out. Temps will top out maybe a few deg above
normal assuming the clouds break early enough in the day. The deep
convection should move off to the east by mid-evening or so.

For tonight, we should have more quiet weather. Can`t rule out a few
showers in the westerly upslope areas along the TN border. Drying
aloft suggests some fog potential, also assuming some locations
get the rain late in the day. Low temps should cool off a bit,
but still above normal.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 150 AM Monday: Kicking off a quieter stretch Tuesday as the
surface cold front heads out to sea and drier air filters in behind.
The upper low continues to lift toward the NE. Meanwhile, an omega
blocking pattern emerges over the CONUS and keeps trough toward the
north of the CWA. The pressure gradient is not anticipated to be
tight, so some low-end wind gusts possible across the higher
elevations through the end of the period. Guidance from the GFS and
Euro does suggest a stray shower across the far northern NC
mountains Tuesday afternoon, but models have also been trending
drier over the past few forecast cycles. So confidence is very low.
Upper flow should start to turn more NW by Wednesday night as the
ridge axis over the central plains moves eastward. Will keep non-
zero PoPs at this point. Temps will be warmest Tuesday during the
short term and decrease closer to climo by Wednesday. Overnight
temps will also be on the decline Wednesday night as drier air
continues to move in and drop dewpoints.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 155 AM Sunday: By Thursday, a semi-strong omega blocking
pattern continues over the CONUS, leaving the CWA in a weakening NW
flow regime. Thursday and Friday will remain dry as heights begin to
rise gradually as the ridge axis out west approaches the area. By
Saturday, the axis will be over the CWA and also dry. Guidance does
start to diverge on the next potential chance for showers. The Euro
develops a weak upper low and trough that approaches the area by
Sunday. However, the GFS keeps this weakened low from really forming
and prevents any rainfall from reaching the CWA through the end of
the forecast period. Either way, there`s very little confidence in
this as we start to transition into a more summer like pattern. So
for now, consider the extended forecast dry and warm. Temperatures
should remain close to climo.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Dealing with a few showers over the NW
Piedmont of NC, otherwise we are in the lull before the next line
of storms arrives from the west. There could be some brief fog
restrictions at any of the terminals prior to the arrival of the
line, but VFR should prevail with light/var wind. The guidance is
fairly consistent in bringing a line of strong/severe storms up to
the TN border around 09Z. Confidence is highest with KAVL thunder
probs this morning, but east of the mtns the situation is much less
certain, as a few of the CAMs show this really struggling to make it
east of the Blue Ridge. The line appears to be organized well enough
that discretion suggests keeping a TEMPO for all terminals for now,
until we are more certain that the line will actually diminish and
dissipate, which should happen in the mid/late morning at any rate
during the diurnal minimum. Wind should be SW. This afternoon is
also uncertain, but several of the CAMs still develop scattered
storms after sufficient air mass recovery happens. Will include
a PROB30 at most terminals to account for this. By nightfall,
the convection should be to the east. The passage of the front is
expected to happen in the late evening or early morning Tuesday,
bringing a shift to the NW. It remains to be seen how much fog
we get around daybreak Tuesday, but the guidance is keen on fog
development.

Outlook: Drier weather is expected by midweek with VFR conditions.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...PM
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM