-- Discussion containing changed information from previous version are highlighted. --
831
FXUS62 KGSP 090728
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
328 AM EDT Sun Jun 9 2024

.SYNOPSIS...
-- Changed Discussion --
A cold front moves in today with returning shower and thunderstorm
chances, mainly this afternoon and evening. The front moves south of
the area Monday and Tuesday with dry conditions expected. 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.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 300 am Sunday: Large scale height falls will carve our a broad
trough across the East by end of the period, with a series of
embedded MCVs expected to ripple across our region, esp this
afternoon and evening. A cold front is forecast to move into the
forecast area this afternoon, and move steadily east throughout the
afternoon/evening. This will provide the primary focus for
initiation of deep convection. Uncertainty persists regarding the
magnitude of destabilization this afternoon, owing primarily to
uncertainty re: the extent of thickness of debris cloud from
upstream convective complex and attendant impacts on insolation. Our
best guess based upon a consensus of deterministic and probabilistic
guidance is that sbCAPE will peak at around 1500 J/kg across much of
the area this afternoon. With deep layer shear expected to range
from 30-40 kts, instability is expected to be just enough to yield a
marginal severe storm threat. Shear values may support a couple of
rotating cells, but forecast low level shear and SRH values are such
that the tornado threat is minimal, and isolated damaging wind gusts
and large hail will be the main threats.

Max temps are forecast to be about a category above normal, with
temps likely reaching or exceeding the 90 degree mark across the
southeast quadrant of the CWA. Convective chances linger into the
overnight hours, especially across the southern half of the CWA, as
the front takes its time clearing the area of moisture. However,
overnight convection is expected to be tame...likely more showery
than anything...as instability quickly weakens owing to very poor
mid-level lapse rates. Min temps are expected to be close to
normal.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
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 /WEDNESDAY THROUGH SATURDAY/...
-- Changed Discussion --
As of 300 AM EDT Sunday: Run to run consistency is still out of
whack amongst the guidance, especially for the second half of the
medium range. One thing that seems evident is the airmass will
moderate, with hot and muggy conditions returning by the extended
forecast period. Model guidance continue to develop a surface low
over the eastern Gulf, but becomes nearly stationary due to very
weak steering flow. The GFS and ECMWF keeps the CFWA dry for a good
portion of next week, with some resemblance of a rex blocking
pattern developing. Going to stick with the NBM due to the low
confidence in the forecast, but will need to monitor the position of
this low as a heavy rainfall threat will occur if it lifts north
into the region at any point due to the plume of deep tropical
moisture associated with this system. Temperatures will be slightly
above normal for much of the period.
-- End Changed Discussion --

&&

.AVIATION /08Z 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...CAC
NEAR TERM...JDL
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JDL