323
FXUS62 KGSP 061043
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
643 AM EDT Fri Jun 6 2025

.SYNOPSIS...
Several storm systems moving across the area will allow for
scattered to numerous thunderstorms through this weekend with a few
possibly becoming strong to severe, mainly during the afternoon and
evening hours. Unsettled weather will stick around through the
middle of next week as a cold front stalls in/near the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 630 AM EDT Friday: Only a few changes this morning, mainly for
aviation grids, but did make some minor tweaks to pop trends through
the morning. Temperatures are looking pretty good. Patchy dense fog
this morning showing up espousal around waterways as midlevel
clouds cleared out, and mountain valleys pretty well socked in.
Should see rapid improvement with sunrise.

Otherwise, nearly zonal flow in place for the near term, with a mid-
level weakness pushing through the pattern from the Central Plains
toward the Southern Appalachians today atop a low-amplitude ridge
over the western Gulf/Southern Plains. The coastal low that brought
the cooler temperatures and cloudiness the past couple of days will
lift out of the area, and with its exit, we should expect markedly
different conditions today with much warmer temperatures as weak
downsloping behind the surface boundary, slightly higher thicknesses
and increased insolation all combine to result in a good 10+ degrees
warmer than yesterday especially east of the mountains where there
was more cloudiness yesterday, and a handful of degrees above normal.

With the increased sunshine and return to a typical (above typical)
summertime regime, expect afternoon destabilization with SBCAPEs
increasing to 1500-2000 J/kg, depending on which model you choose.
As the mid-level weakness moves toward the area this afternoon,
convective initiation over the mountains will blow off toward the
Piedmont, with hints of a leftover MCS approaching the TN/NC state
line after sunset as the shortwave nears. SPC Marginal for Day 1 is
reasonable for most of the area, with the Slight nudging into
extreme western zones depending on how far east across the TN Valley
the more organized convection is able to sustain itself. Isolated
severe certainly not out of the question but best deep layer shear
remains to the west for the near-term.

Increasing moisture tonight in the warm sector ahead of the short-
term system will lead to much warmer and muggy overnight lows.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 219 AM Friday: An unsettled pattern will continue into the
weekend with multiple rounds of showers and thunderstorms possible.
A stout upper ridge will be centered from northern Mexico across the
Gulf Coast and much of the Gulf itself. On the poleward side of the
ridge, a series of shortwave troughs embedded within a belt of
westerlies will be quickly pushing out of the Central Plains and
into the Ohio River Valley and Appalachians by Saturday night.
Forcing from the waves will help to instigate several upstream
convective complexes across the Deep South and portions of the
Tennessee Valley. With time, this activity will push towards the
Southern Appalachians by late Saturday afternoon into the evening
hours. Forecast confidence lowers with regards to where this occurs
as it will be dictated by convection today and resulting mesoscale
boundaries that are left behind. CAM guidance is also notorious for
poor handling of summer time MCS patterns and often struggles
considerably as to where/when convective complexes initiate and
propagate. With that being said, a conditional severe weather threat
will be possible across the entire area as the parameter space will
easily be supportive of MCS maintenance into the region. Surface-
based instability is progged around 1500-2000 J/kg with around 40
kts of deep-layer vertical wind shear within the westerly flow
regime. IF an upstream MCS were to track into the area a threat for
damaging winds would be probable, however the forecast could remain
rather quiet if any MCS track just misses the area to the south.

Heading into Sunday, a large closed upper low is forecast to drop
into the Northern Plains with a lead shortwave trough lifting across
the Midwest and into the Mid-Atlantic. An attendant surface low will
slide across Indiana and Ohio with a surface cold front dropping
through the Mid-South and into Kentucky. Additional showers and
thunderstorms are possible across the western Carolinas and
northeast Georgia ahead of the front and a couple strong
thunderstorms cannot be ruled out. Shear will be much weaker,
however, and will generally preclude a threat for organized severe
weather.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 234 AM Friday: Unsettled weather is expected to persist into
next week with near daily chances for showers and thunderstorms. The
previously mentioned advancing cold front will try to push into the
area on Monday, but how far it progresses remains uncertain at this
time range. Guidance is in generally good agreement that the
boundary will stall in or near the area with perhaps a lull in
activity on Monday. The forecast turns wet again through the rest of
the period as guidance depicts the boundary lifting back across the
area and then stalling as flow weakens and upper forcing wanes. This
will keep at least scattered to numerous diurnally driven showers
and thunderstorms across the area. Several weak waves later in the
week may enhance coverage further.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Smattering of IFR to VLIFR conditions
across the area, with KHKY and KAND ending up the restriction
winners as far as worst conditions this morning. KAVL went down
briefly, and the low stratus managed to stay east of KCLT for the
most part with just brief MVFR conditions. Restrictions will be
short-lived over the next hour or so, as the area should generally
see rapid improvement with sunrise, with the exception of the
mountain valleys where the fog/low stratus will linger for a couple
of hours still. Transitioned PROB30 to VCTS for KAVL but not
confident enough at other TAF sites so left thunder mention out for
the time being and will let later forecasts introduce as necessary.
Will likely see restrictions again Saturday morning at least at
KAVL/KHKY. Too early to introduce PROB30 for Saturday at this time.
Lgt/vrb winds at TAF time will pick up 5-10kt this afternoon, and
back lgt/vrb again overnight. Direction should generally stay on the
S side of W, but would not be surprised if they go briefly on the N
side.

Outlook: An active period is expected with scattered diurnal
showers and thunderstorms each day along with the potential for
late night/early morning fog/low stratus restrictions.

&&

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

&&

$$

SYNOPSIS...TW
NEAR TERM...TDP
SHORT TERM...TW
LONG TERM...TW
AVIATION...TDP