931
FXUS62 KGSP 090610
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
210 AM EDT Sun Jun 9 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 TODAY/...
Key Messages:

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

2) Isolated strong to severe storms are possible this afternoon/
evening.

As of 2 am EDT Sunday: A short wave trough will translate off the
Carolina Coast early today as a very broad upper low deepens 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 this aftn and evening. Sct
showers could move into the mtns by late morning with another round
of sct showers and thunderstorms expected to move thru the 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 outlook still has most of our CWA in a Marginal Risk for
isolated severe storms, which appears reasonable owing to forecast
deep-layer shear of 30 to 35 kts this afternoon. Some amount of
sfc-based instability will also be in place during the aftn/evening
hours, however model profiles vary quite a bit wrt magnitude, with
sbCAPE ranging anywhere from a few hundred to about 1500 J/kg. 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, 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.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
As of 145 AM EDT Sunday: The aforementioned cold front will be in
the vicinity of the southern portion of the CFWA and may keep a few
lingering showers across the Upstate and northeast Georgia through
mid-morning Monday. Otherwise, drier air filters in by Monday
afternoon thanks to a continental surface high building in from
the northwest and the front continuing to push southward. Cyclonic
flow aloft will remain in place as the area of high pressure sets
up shop across the southern/central Appalachians by the end of
the forecast period. A shortwave will carve out of the base of the
cyclonic flow and shift the axis offshore by 12Z Wednesday. Either
way, the sensible weather will remain dry after Monday morning
with temperatures at or slightly below normal for max/min through
the short term.

&&

.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 /06Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR conditions are forecast to continue
through the period. Mid and high level clouds will steadily
increase, especially toward sunrise and through the daylight hours.
Increasing moisture and instability ahead of an approaching cold
front is expected to support scattered shower/thunderstorm
development across the Terminal Forecast Area during the afternoon.
Prob30s for TSRA are warranted at most sites, primarily from late
afternoon into the evening hours. Winds will favor light SW or
light/vrbl this morning, increasing to SW at around 10 kts late
morning into the afternoon, with some gusts in the 15-20 kts range
possible. Directions will turn toward the W/NW during the late
afternoon and evening as the cold front pushes through the area.

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

&&

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

&&

$$

SYNOPSIS...RWH
NEAR TERM...AR/JDL/JPT
SHORT TERM...CAC
LONG TERM...RWH
AVIATION...JDL