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168
FXUS62 KGSP 090254
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1054 PM EDT Sat Jun 8 2024

.SYNOPSIS...
A cold front moves in on Sunday with returning shower and
thunderstorm chances. The front moves south of the area Monday and
Tuesday. Forecast confidence lowers through the rest of the week as
overall pattern is uncertain. For now, a chance of afternoon and
evening showers and thunderstorms is expected with above normal
temperatures.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
Key Messages:

1) High temperatures could break 90 degrees outside of the
mountains on Sunday.

2) Isolated strong to severe storms are possible on Sunday.

As of 10:25 PM EDT Saturday: Cloud cover has diminished across
much of the Upstate and NE Georgia late this evening. Sct mid
and high clouds continue to make their way eastward over western
NC. The rest of the night and overnight should be quiet with any
precip unlikely and relatively dry dewpts limiting any fog poten-
tial overnight. Light winds from the southwest and some amount
of lingering cloud cover, should keep low temps a few degrees
above climatology.

Otherwise, an embedded upper shortwave will translate off the
Carolina Coast early Sunday as a very broad upper low amplifies
over the Great Lakes but remains to our north. At the sfc, high
pressure will linger well offshore as a weak cold front approaches
from the NW overnight and then moves thru our area Sunday aftn
and evening. Cirrus will gradually increase in coverage Sunday
morning as the front approaches. Sct showers will likely move
into the mtns by the late morning with another round of sct
showers and thunderstorms expected to move thru our CWA later
in the aftn and thru the evening. Coverage remains challenging
to pin down, but still anticipating the best coverage over the
NC mtns and into the Piedmont with less coverage the further
you go south. SPC`s day 2 Severe Wx Outlook still has most of
our CWA in a Marginal Risk for isolated severe storms on Sunday.
This still appears reasonable as most of the near-term guidance
has 35 to 50 kts of deep-layer shear across our area on Sunday.
Some amount of sfc-based instability will also be in place during
the aftn/evening hours, however model profiles vary quite a bit
wrt amounts ranging anywhere from a few hundred J/kg to about 1500.
As such, the main hazards with any stronger storms that develop
will be damaging wind gusts and large hail. With increasing WLY
low-level flow ahead of the front on Sunday, temperatures will
continue to climb and are expected to top-out at or just above
90 degrees across much of the lower terrain. Temps in the mtns
should remain in the upper 70s to mid 80s.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
As of 145 PM EDT Saturday: Short waves carve a trough over the East
Coast Monday with the trough axis moving off shore Tuesday. At the
surface, a cold front crosses the area Sunday night, stalls near the
area Monday before pushing south on Tuesday. Expect ongoing
convection Sunday evening will taper off through the night, but
isolated showers may linger into Monday with lingering low level
moisture and weak forcing. Dry conditions expected on Tuesday as a
drier air mass moves in from the north. Breezy conditions Sunday
night and Monday will taper off Monday evening as the pressure
gradient relaxes. Lows near to slightly above normal Sunday night
drop around 5 degrees Monday night. Highs Sunday and Monday remain
nearly steady around normal.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 210 PM EDT Saturday: Guidance continues to show little run to
run consistency as they waffle back and front from a wetter to drier
pattern through the period. Have gone close to the model blend given
the low confidence in the forecast which results in isolated to
scattered mainly diurnal convection each day. The overall pattern
begins with a short wave ridge on Wednesday then a weak zonal flow
which weakens or becomes a ridge for Saturday. Weak high pressure
over the area Wednesday moves east as cyclogenesis takes place along
the Gulf Coast. The resulting low pressure center may remain nearly
stationary with a decent southerly fetch into the area. The low may
cross FL and move up the Atlantic Coast, which would also keep
moisture over the area. Or the low could remain suppressed as it
crosses FL and moves into the Atlantic, which would be a relatively
dry pattern. This is why confidence is low and forecast relies on
the model blend. This also results in temps bouncing around but
remaining above normal through the period.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Key Messages:

1) Dry Conditions Linger thru Tonight

2) Shower and Thunderstorm Chances Return Sunday

At KCLT and elsewhere: expect VFR conditions to continue thru the
00z taf period. Mid and upper level clouds will remain sct over the
area thru tonight and into the overnight. A cold front approaching
from the NW will move thru our area on Sunday and bring sct showers
in the afternoon with a round of thunderstorms likely that evening.
Coverage and timing of both the showers and thunderstorms is still
fairly uncertain at this time, so I kept a PROB30 for shra with a
PROB30 for tsra later in the day at each terminal. Winds outside of
the mtns will weaken tonight and continue to favor a SW to WSW direc-
tion thru tomorrow morning. They will become more WLY tomorrow aftn
and pick up in speed with some low-end gusts possible, especially at
the Upstate terminals, as the cold front moves thru the area. At KAVL,
winds will go light and vrb later tonight and eventually pick up from
the NW on Sunday with low-end gusts likely.

Outlook: drying sfc high pressure is expected to gradually spread
over the area on Monday and linger thru the first part of the week.

&&

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

&&

$$

SYNOPSIS...RWH
NEAR TERM...JPT
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...JPT