763
FXUS62 KGSP 191751
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
151 PM EDT Sun May 19 2024

.SYNOPSIS...
Warming high pressure will build atop the region through the first
half of the week. Along and ahead of a stalling cold front, showers
and storms return on Thursday with chances continuing all weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1140 AM: Forecast moving along as expected this morning, so
minimal changes were made as we head into the afternoon. Expect
the cloud cover to gradually scatter out over the Piedmont. No
need yet to make any changes to precip probs.

Otherwise...a closed low is centered over GA embedded within
a shortwave which will slowly drift east into the Carolinas
today. Main precip remaining over the area is very light and
associated with deformation zone of the shortwave or via very
weak convection along the front itself. Updated PoPs to allow this
precip to slowly decay and focus increasingly south.

Beneath the shortwave, we retain pretty good lapse rates through
most of the daytime hours. The northeasterly flow associated with
the sfc high is deep and forcing really comes from the CAA, with
no appreciable warm upglide. A subsidence inversion will persist
over most of the Piedmont and should preclude new convection there
this afternoon. However, over the mountains, the inversion will
be weaker but also some degree of low-level convergence will be
present owing to slightly more backed flow behind the shortwave
meeting the easterly flow from the high. This should provide
slight forcing. Deep dry air in the mid to upper levels would
appear difficult for the relatively mild instability to overcome,
so PoPs have been limited to chance range in the mountains. Storms
likely will be slow moving but PWATs will be considerably lower than
what we saw overnight, somewhat mitigating heavy rain threat. With
the NE winds continuing, max temps will be several degrees below
normal despite partial sunshine. Remaining PoPs will diminish
nocturnally; some low stratus could develop near the Blue Ridge
Escarpment overnight in the wedgelike easterly flow. Mins will be
around normal.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
As of 1205 PM EDT Sunday: The warming trend will continue through
the forecast period as lower elevation max temperatures climb into
the middle 80s by Wednesday.  Building upper ridge atop the SE CONUS
will keep the atmosphere suppressed, save for diurnal isolated
ridgetop deep conection in the NC mtns Tuesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
As of 100 PM EDT Sunday: With developing lee trough and some
downslope warming, Thursday has the potential to be the hottest day
of the week with piedmont upper 80s possible, as long as convective
and/or debris clouds limit insolation too early in the day. It looks
like an active frontal zone is progged to approach and stall in or
near the cwfa on Thursday as it becomes parallel to the upper flow.
This baroclinic zone should be able to aid in showers and tstms
becoming numerous, especially across the mountains Thursday
afternoon.  Within the wavy quasi zonal flow atop the region Friday
and into next weekend, daily, diurnally enhanced tstms are probable
each day with temperatures averaging above the late May climo.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: We continue to deal with the remnants of
an MVFR-level stratocu deck across the region east of the mtns
this afternoon. Now that it was scattering out, enough heating
should develop to more or less fill any holes with new convective
clouds, so most likely the terminals will be in-and-out of the same
MVFR-level bkn ceiling until we start to lose the daytime heating
after 22Z or so. Meanwhile, over the mtns, low level convergence
will continue to support scattered shower development, with an
isolated thunderstorm possible. This will necessitate the inclusion
of a TEMPO at KAVL for some showers thru late afternoon. By sunset,
any wind gusts should go away and we should start to lose the
lowest cloud layer, and we should be left only with some lingering
scattered clouds. A light NE wind should remain overnight with high
pressure to our north. Some of the guidance redevelops another
low cloud deck around sunrise across the Piedmont, but this is
low confidence at this time and was not included as a ceiling with
this package. Monday looks nice a quiet.

Outlook: Stronger high pressure settles over the region Monday
and persists through midweek, but isolated mountaintop convection
still appears possible both Monday and Tuesday afternoons. Precip
and restrictions possible with next front arriving circa Friday.

&&

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

&&

$$

SYNOPSIS...CSH
NEAR TERM...PM/Wimberley
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...PM