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000
FXUS62 KGSP 160158
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
958 PM EDT Sat May 15 2021

.SYNOPSIS...
It will continue to warm up through Sunday with a gradual increase
in daily shower chances through Wednesday.  Sprawling Bermuda high
pressure will aid in the onset of summerlike conditions by the end
of the upcoming work week.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 955 PM: Fcst on track. Cirrus are beginning to spread
across the Appalachians, in the northwest upper flow and ahead
of an approaching shortwave; some diurnally generated cu remain
trapped under subsidence inversion. Even though heights rise
through the period, northwest flow remains with additional weak
short waves moving across the area through the flow. The center
of high pressure settles over the area but a weak warm front
approaches the northern mountains from the west. This could be
enough for highly isolated showers across the northern mountains
by morning, but based on current guidance saw fit to reduce PoP
slightly there; there just isn`t much forcing to work with. The
upstream radar echoes associated with the aforementioned
shortwave don`t appear to be producing much at the ground, if at
all, and with the wave dampening as it moves in our direction,
looking unlikely we will see anything aside from perhaps a stray
sprinkle tonight. Think decent radiative conditions will
develop despite the high cloud cover; brought mins down another
degree or two in the typically cooler areas. But with dewpoints
looking a little lower, Little TN Valley fog is looking a little
more patchy. Lows will be a few degrees below normal.

Weak instability develops across the mountains and northern tier
of the CWFA Sunday. This combined with the lingering moisture,
short wave activity, warm frontal advance, and even some upper
divergence will produce scattered showers over the much of the
NC mountains and northern foothills. Isolated showers may develop
to the south and over the NW Piedmont. Can`t rule out a rumble of
thunder or two during the afternoon. Conditions are less favorable
over the NC southern Piedmont, NE GA, and the bulk of the Upstate,
so a dry forecast continues there. Despite the lingering clouds,
rising heights and thickness values suggest highs near normal
for all but the mountains where they will continue a few degrees
below normal.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 1210 PM EDT Saturday: It is still looking like isolated
diurnally fired tstms remain possible along the I-40 corridor
Monday afternoon, within the developing weak instability axis and in
proximity to retreating weak wedge boundary. Across the southern
half of the cwfa, further into the warm sector and higher heights,
the atmosphere should remain capped as max temperatures creep to
just above the mid-May climo. Despite the trend of upper ridge axis
sharpening up atop the region on Tuesday, llvl baroclinic zone along
with a weak llvl pattern waa exists and should be the focus for
scattered diurnal deep convection, especially in the piedmont where
the better llvl convergence is progged.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 100 PM EDT Saturday: Upper level ridging strengthens atop the
eastern seaboard to start off the period.  Sensible wx should be
limited to diurnally fired storms over the high terrain as the llvl
flow around mid-atlantic hipres ascends the Blue Ridge.  Deeper
layered ridging is expected to keep the atmosphere supressed
regionwide Thursday thru Saturday with a warming trend on tap,
featuring solid upper 80s for piedmont max temps by the end of the
period.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR expected at the terminals this period. A
few stratocu may be seen this evening, but the primary cloud cover
will be cirrus associated with a dampening shortwave moving from
KY/TN into NC. A sprinkle can`t be ruled out at KAVL or KHKY,
but likely of no impact. Cirrus likely will peak in coverage in
the early morning, but diurnal cu will be a bit more plentiful and
lower Sunday with replenished moisture, and they predominate. Winds
are a little trickier, expected to be mainly light/variable tonight
though tending SW for the Piedmont sites and NW at KAVL. A shift to
NW and eventually NE is suggested for KHKY/KCLT/KGSP/KGMU Sunday
afternoon, with a weak boundary setting up and high pressure over
the Mid-Atlantic.

Outlook: VFR conditions should generally prevail into early next
week, although brief restrictions in morning low stratus and/or
fog will remain possible, mainly in the mountain valleys. Diurnal
shower chances will increase early next week, although coverage
is expected to be widely scattered at most.

Confidence Table...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:

www.weather.gov/gsp/aviation

&&

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

&&

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