666 
FXUS62 KGSP 070222
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1022 PM EDT Sat Nov 6 2021

.SYNOPSIS...
A low pressure system will move along the southeast coast through 
the weekend, bringing rain chances to the Carolina Piedmont through 
tonight. Dry and warming high pressure develops for the first half 
of the upcoming week before a significant storm system begins 
impacting the eastern states late in the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 1010 PM EDT: An 1003 mb surface low pressure system continued 
to spin with little movement off of the northern Florida coastline. 
Weak mid-level frontogenesis continued to support an influx of mid-
level clouds near the I-77 corridor with a few sprinkles or light 
showers observed with associated isolated rain bands just east of 
the forecast area. It now appears any light showers or drizzle will 
stop just short of the forecast area. So in this update will trim 
back slight chance showers to at least to eastern Union NC county, 
if not removed altogether. The lastest observations showed dewpoints 
hovering around 30 deg F with temperatures still in the 40s for 
areas where frost may be a concern tonight in active zones north of 
I-85 from Franklin county northeast to Rutherford (mostly excluding 
Greenville county). With mid to high clouds gradually thinning 
overhead, think we continue to be on track for at least patchy frost 
for these areas.

Otherwise, high pressure builds in behind the departing low pressure 
area Sunday. Clouds should scatter out with mostly sunny skies for 
much of the day. Expect low end gusts to redevelop with mixing 
during the morning then tapering off through the afternoon. With 
sunshine returning and increasing thickness values, highs should end 
up near normal.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 1230 PM Saturday: An upper-level low and a coastal low laying 
underneath will continue to meander off the Southeast coast through 
much of the short-term. Ridging aloft will nudge over the region 
from the southwest, while a deep upper anticyclone sets up shop over 
the west-central Atlantic. This will keep the coastal low from 
moving much, but will gradually push eastward as upper ridge deepens 
from the southwest and takes control of the large-scale pattern. 
With a surface high in place over the southeastern CONUS, expect dry 
and mostly sunny skies through the forecast period. Rising heights 
from the upper ridge will raise our daily max temperatures to above 
normal values by Monday and Tuesday. Good radiational cooling 
conditions during the nighttime period will cause overnight lows 
Sunday night to dip into the mid to upper 30s across the piedmont 
and lower 30s for the high country. Expect areas of frost to develop 
or most locations. Monday night will be a slightly different story 
due to the rise in thicknesses, which in turn will raise overnight 
lows to near normal values. Either way, expect a large diurnal cycle 
for the new work week.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 200 PM Saturday: By the middle part of next week, the
aforementioned upper ridge begins to flatten out in response to a
potent shortwave trough that quickly pushes across the northeastern
CONUS. Surface high will still be in control, but the warming trend
will likely plateau Wednesday and beyond. Max temperatures will
remain a few degrees above normal through much of the upcoming
work week, while lows gradually increase as an uptick in cloud
cover develops and a better moisture flux enters the CFWA from
the southwest. Changes begin to take place by late Thursday into
the day Friday as global models continue to spit out a vigorous
storm system over the eastern CONUS.

The overall consensus has a similar synoptic setup with a potent
upper trough swinging in from the west. The timing and location of
the frontal system are a bit different with the GFS sending the
attendant front through the CFWA by early Friday, with little
to no QPF response besides the TN border. On the other hand,
the ECMWF has a wetter solution, with a good frontal zone and
QPF response ahead and along the boundary. Also, the ECMWF has
the attendant front entering the CFWA 6-12 hours later compared
to the GFS. Highest PoPs will be late Thursday into Friday to
account for all global model solutions. The GFS and ECWMF QPF
response is unimpressive, but the outlier that is the Canadian,
produces very high QPF amounts, which could lead to an excessive
rainfall threat in this scenario. The overall severe threat is
nonzero at this time, but continues a downward trend as the GFS and
ECMWF come to better terms. Temperatures will likely remain above
normal for both highs and lows through the rest of the period,
with the exception of day 7 as we favor a post-frontal regime.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: MVFR to VFR cigs will prevail through 08Z to 
12Z mainly east of the mountains and especially near the I-77 
corridor including KCLT. Low end gusts will likely return for many 
terminals between 13-16Z. High confidence in VFR conds prevailing 
all sites after 14Z.

Outlook: No significant flight restrictions are anticipated through 
at least Wednesday with high pressure over the area. However, 
morning mountain valley fog will be possible.

&&

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

&&

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