750 
FXUS62 KGSP 071922
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
222 PM EST Sun Nov 7 2021

.SYNOPSIS...
Dry and warming high pressure will continue across the region 
through the middle of the week. A significant storm system is then 
expected to bring a return of unsettled weather late in the week. 
Much cooler temperatures are expected to arrive next weekend.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 155 PM EST: Upper ridge axis and surface high pressure will 
build into the area tonight with clear skies as the coastal low 
moves east. This should make for good radiational cooling 
conditions. That said, the air mass building in from the west is 
moderating, and wind may not quite decouple and go calm until late 
tonight. A good inversion will keep ridge tops warmer than the 
valleys. MOS guidance for our Coop sites is colder than many of our 
obs sites. Therefore, expect a distinct urban/rural split between 
warmer and colder temps. Near lake areas will also be warm. Still, 
experience says when frost/freeze cases are marginal, they usually 
tilt toward the colder side. Therefore, will issue a Frost Advisory 
for all counties where the growing season is still active, knowing 
that some locations, possibly even more than half of some counties, 
will remain just above frosty temps. Lows around 5 degrees below 
normal.

Expect a mild, sunny day with overall light winds Monday as high 
pressure and upper ridge remain in place. Increasing thicknesses and 
a dry atmosphere will lead to highs around 5 degrees above normal. 
While dew points are not forecast to be as low, the air mass is very 
dry. Warmer highs may lead very low RH values which could create a 
fire weather concern for NE GA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 100 PM Sunday: Upper ridge from the west will expand over the 
eastern third of the CONUS Monday night into Tuesday with surface 
high helping to control the overall weather pattern. Expect dry 
weather to be in store as thicknesses rise to 582-585 dm. This will 
push max temperatures Tuesday to 5-10 degrees above normal. A decent 
shortwave trough will quickly push north of the region and gradually 
breakdown the ridge Tuesday night into Wednesday with increasing 
clouds. Expect the surface high to slowly push off the southeast 
coast and bring a return flow back into the CFWA by Wednesday. Dry 
weather and above normal temperatures will continue through the end 
of the short-term. With good radiational cooling conditions Monday 
night, overnight lows will be near-normal under a starlit sky. 
Increasing clouds will keep overnight lows Tuesday slightly above 
normal. ~30 degree diurnal cycle will occur both Tuesday and 
Wednesday.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 210 PM Sunday: The extended period will primarily focus on a
deep upper trough that will push into the region from the central
CONUS starting Thursday. Model guidance are in consensus with the
overall pattern. The ECMWF and GFS send a shortwave ahead of the
upper trough with an attendant frontal boundary Thursday night
into Friday. Low-level moisture will increase as the frontal system
approaches the CFWA. The upper trough will take its time to push
through the East Coast. Expect the trough axis will enter the region
Friday night into Saturday, while the axis lifts east of the CFWA
Saturday night into Sunday. A lot of uncertainty remains with the
evolution, timing, and location of the dynamics associated with this
vigorous system. As of now, guidance is trending towards a wetter
solution and potentially washing the front out over the region. PoPs
will be in store from Thursday night through Saturday for the new
trend. An excessive rainfall and severe threat can't be ruled out
with this setup. With extensive cloud cover and increasing PoPs,
expect temperatures to moderate and gradually dip below normal by
Saturday and remain that way through the end of the period.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions expected thru the period,
except for patchy mountain valley fog again tonight. Cirrus 
associated with the coastal low pressure will move east of the area 
today. Gusty northerly winds associated with the low will diminish 
through the afternoon as well. Light northerly wind expected this 
evening and overnight with some increase in speed Monday. SKC 
expected overnight and Monday.

Outlook: No significant flight restrictions are anticipated through 
at Wednesday with high pressure over the area. However, morning 
mountain valley fog will be possible. A cold front will bring the 
chance of precipitation and associated restrictions Thursday and 
Friday.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Frost Advisory from midnight tonight to 9 AM EST Monday for 
     GAZ018-026-028-029.
NC...Frost Advisory from midnight tonight to 9 AM EST Monday for 
     NCZ071-082-508-510.
SC...Frost Advisory from midnight tonight to 9 AM EST Monday for 
     SCZ004>014-019.

&&

$$
SYNOPSIS...DEO
NEAR TERM...RWH
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...RWH