188
FXUS62 KGSP 270557
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
157 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 TODAY/...
As of 1214 AM EDT Monday: Still watching a rogue thunderstorm over
Fairfield County SC, which may clip the southeast part of the
Charlotte metro area, otherwise we have entered the lull before
the next line of severe storms arrives from the west. Won`t rule
out some fog in the interim. We look upstream across middle TN in
anticipation of the line reaching the NC mountains in the pre-dawn
hours. No word on watches this far east yet. Seems reasonable that
the line would still have enough oomph to produce some wind damage
along the TN border before it dies crossing the ridge.

Otherwise, a final round of storms will be possible during peak
heating on Monday, but will need a few factors to come together for
it to reach its full potential. This one will be dependent on how
much the environment recovers from the early morning convection
and if the atmosphere regenerates more instability. As of now,
CAMs do exactly that, with dewpoints in the uppers 60s to near
70 and instability quickly redeveloping by peak heating, ahead
of an incoming cold front. Deep layer shear will remain elevated
(35-45 kts) and curved hodographs would support rotating supercells
on Monday. The question will be if we can tap into any surface
instability to take advantage of the otherwise really good
kinematics in place. If instability becomes realized Monday
afternoon, all three hazards will be possible (large hail,
damaging winds, tornadoes) with upscale growth by the time the
storms get into the eastern zones and east of the CFWA. The only
thing about this forecast is that it will remain uncertain until
we see what happens with the second round of convection that`s
expected overnight. Decided to lower temperatures slightly for
Monday as convective debris will be hard to shake off, especially
during the morning hours. As a result, afternoon highs on Monday
will be at or slightly above normal.

&&

.SHORT TERM /TONIGHT 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 /06Z 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...CAC/PM/TW
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM