460
FXUS62 KGSP 192357
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
757 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 MONDAY/...
As of 755 PM Sunday: Dry northeasterly flow continues to filter in
dry air and allowing clouds to scour out. Still some ongoing
convection near the Little TN Valley, but should quickly fade away
after the sunsets. Otherwise, the forecast remains on track outside
of some adjustments based on latest trends and current observations.

Behind this band of light precip, the atmosphere is more or less
capped by a subsidence inversion, which should keep the western
Piedmont and northern Upstate shower-free. Meanwhile, convergence
across the mtns between northeasterly flow over the Piedmont and
more northerly flow over the west side of the mtns continues to
support scattered showers. This should continue thru peak heating,
with enough buoyancy to support an isolated thunderstorm. We`ve lost
the deep moisture, so the threat for heavy rain looks minimal.
Temps/dewpoints were close to fcst.

Over the next 24 hours, the remnant of the old upper system should
drift off the Southeast Coast and a positively-tilted mid/upper
ridge will slide in from the west. For the most part, this will
keep our weather fairly quiet tonight and Monday, however there
won`t be much of an air mass change and we retain relative high
moisture in the boundary layer. That could allow for some areas of
low stratus and fog later tonight, but nothing that appears to be
dense at this time. On Monday, the remnant low level moisture may
pool over the mtns just enough to allow the weak cap to be overcome
in the afternoon, resulting in some isolated shower activity. Temps
should be close to normal.

&&

.SHORT TERM /MONDAY NIGHT 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 SUNDAY/...
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 /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Most of the stratocu from earlier has
dissipated and shifted east of the area. Some lingering cloud debris
from the showers and thunderstorms over mountains may linger for the
next few hours, but that will quickly fade away after sunset. 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...CAC/PM
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...CAC/PM