864 
FXUS62 KGSP 061406
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1006 AM EDT Mon Sep 6 2021

.SYNOPSIS...
A weak cold front will move through the forecast area today 
bringing isolated to scattered showers to the region. Another 
cold front is expected to cross our area late Wednesday and 
bring more showers and possibly a few thunderstorms. Drying 
high pressure will spread back over the region in the front's 
wake and linger into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM: Light patchy showers continue mainly over the SE
half of the CWA, along and ahead of a cold front. Latest CAMs
depict the activity continuing to wane over NC and the northern
tier of GA/SC zones today, but with convection redeveloping over
the Lakelands near peak heating and then propagating east. This
makes sense in light of the front sagging southward very slowly,
allowing for some moisture pooling and destabilization on its warm
side before it exits our area. QPF still looks to generally be
light, but moderate values are possible in any heavier showers
and thunderstorms that do develop in the southern zones later
today. Highs will be near or just below normal.

The front pushes south of the area this evening with convection
quickly tapering off with loss of heating and drier air moving
in. The front may stall in our vicinity by late evening, and will
have to re-evaluate nocturnal PoP/QPF after full slate of 12z
guidance arrives. Should see a return of mountain valley fog,
with patchy fog elsewhere. Lows will be near or just below normal.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 315 AM EDT Monday: The short-term fcst picks up at 12z 
on Tuesday with upper trofing lifting off the coast of Maine 
as another upper trof begins to dig down over the Western Great 
Lakes and broad upper ridging remains in place over the Western 
CONUS. Over the next couple of days, the trof will dig farther
southward and is expected to be centered just to our north by
the time the period ends early Thursday. At the sfc, a weak 
cold front will be nearly stalled just to our south and east 
by early Tuesday, as high pressure spreads farther eastward 
and over the western Carolinas. Some degree of weak, SLY return 
flow is still expected to develop over the CWA Tues afternoon 
as high pressure shifts more NE. This will allow whatever is 
left of the frontal bndy to drift back northward and bring more
moisture into the CWA from the south. On Wednesday, another 
cold front will approach the area from the NW and move thru
the CWA late Wed into early Thurs. Overall, the models have
been slowing the progression of this front and it's now not
expected to be clear of the CWA until later Thurs morning.  
Overall, precip chances and amounts haven't changed much from
the previous fcst, with the best chances for more widespread 
precip Wed aftn/evening and PoPs ramping down early Thurs as
the front moves east of the CWA. Temperatures start out just 
above normal on Tuesday and remain a few degrees above normal 
thru the period.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 255 AM EDT Monday: The extended fcst picks up at 12z on 
Thursday with another broad upper trof centered to our north
and gradually moving eastward as steep upper ridging dominates 
the Western CONUS. The upper trof is expected to linger over 
the Eastern CONUS thru the end of the week, with heights likely 
recovering at least some over the weekend as the upper ridge 
deamplifies and spreads farther east. At the sfc, another cold 
front will be moving south and east of the CWA with broad high
pressure spreading over the area in its wake as the period begins 
early Thurs. At the same time, low pressure will try to organize 
over the northern Gulf of Mexico and lift NE and over the Big 
Bend of Florida. The models appear to be coming into better 
agreement wrt how quickly the low will progress NE, with most 
of the guidance moving it off the Southeast Coast late Friday 
or early Saturday and broad high pressure remaining over our
area for the rest of the period. Temperatures start out near 
normal on Thursday and gradually warm above normal over the 
weekend.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: TAF sites remain VFR even with a few SHRA 
passing by. Low VFR cigs are possible later this morning into early 
afternoon. Isolated to scattered SHRA will continue into early 
afternoon. KAND has the best chance of seeing a TSRA, so VCTS in 
place there. Low clouds scatter out behind the front slowly crossing 
the area. SW wind this morning becomes NW then N behind the front. 
KAVL remains NNW through the period. Mountain valley fog likely 
overnight, but uncertain for KAVL, so starting with MVFR there. MVFR 
stratus and/or fog would be possible outside of the mountains if 
moisture is slower to clear.

Outlook: A few SHRA/TSRA may redevelop Tuesday afternoon. A second 
cold front may bring scattered convection Wednesday into Thursday. 
Mountain valley fog and stratus remain possible each morning.

&&

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

&&

$$
SYNOPSIS...JPT
NEAR TERM...RWH/Wimberley
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...RWH