375
FXUS62 KGSP 060704
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
304 AM EDT Thu Jun 6 2024

.SYNOPSIS...
Scattered showers and thunderstorms will develop this afternoon and
linger into the evening. Dry Canadian air will mix across the area
Friday and persist into the weekend. A chance of thunderstorms
returns to the region Sunday, before deeply dry air builds back in
Monday though Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 236 AM Thursday: A deep negatively tilted trough over the
Midwest is forecast to slide into the Great Lakes region today. The
Southern Appalachians will remain on the southern periphery of
forcing for ascent within the base of the trough. Subtle height
falls are still expected to overspread the area, however, in advance
of a surface cold front dropping out of the Ohio Valley. Areas of
low stratus clouds and a couple instances of patchy fog are likely
again through the early morning hours before any fog mixes out and
clouds lift and scatter. Otherwise, the main focus will be for
another round of convection this afternoon, which could be more
robust compared to what we`ve seen the last several days.
Compressional warming ahead of the front along with warming low-
level temperatures will support afternoon highs climbing into the
mid to upper 80s.

Resulting insolation couple with upper 60s to low 70s dewpoints will
yield 2000-3000 J/kg of surface-based CAPE. Increasing flow within
the base of the trough in concert with a low-level jet translating
across the area will also contribute 20-30kts of deep-layer vertical
wind shear. Limited downdraft CAPE and modest lapse rates within a
moist environment will limit the magnitude of any severe threat, but
given the enhanced flow and shear several severe storms capable of
locally damaging winds will be possible. This will especially be
true for any multicell clusters/linear segments that can become
organized along a composite cold pool. Near storm forecast soundings
also depict weak low-level hodograph curvature as the low-level jet
helps to elongate the wind fields. While not overly impressive by
any means, 0-1km SRH nearing 100 m2/s2 could support a
brief/transient circulation or two, which has been picked up on by
several of the CAMs with brief updraft helicity streaks mainly along
and south of I-85. Thus, a brief tornado cannot be completely
discounted. A few storms may linger into the early evening hours,
but will remain progressive ahead of the impending front and should
push out of the area by or shortly after sunset. Thereafter, the
cold front is expected to move through the area overnight with much
drier air advecting into the region in its wake.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 1255 AM Thursday...The short range period remains dry as deep
nw/ly flow commences while a subTrop high shifts east across the srn
Plains. This pattern will support a Canadian sfc high building south
bringing lowering column moisture to the FA. Cooler temps are
associated with this high as well, but downsloping h9-h8 flow will
modify the airmass warmer and allow for max temps arnd normal levels
Fri and Sat. Along with increasing subsidence, the llvls will dry
out with the downsloping and make for dry afternoons with RH values
dropping into the 30 percent range each day. Not much cloud cover
outside of Ci Fri and lowering clouds aloft by Sat afternoon. Mins
will fall to normal levels Thu night and abt 5 degrees cooler Sat
night with no great fog threat each morning.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 115 AM Thursday...No sigfnt changes were made to the ext range
fcst outside of lowering PoPs a bit Sun and Mon. The atmos becomes
more dynamic Sat night with a stg embedded h5 s/w traversing the flow
thru Sun morning. Low level moisture will be limited and only expect
increasing mlvl cloud cover thru mid day. A cold front makes it to
the NC mtns Sun afternoon, but with little upper support, expect the
best precip chances across the NC mtn/fthills due to added mech
lift. Decent agreement is had in the guidance with the progression
of the front as it tracks across the FA during the evening and
overnight. The atmos remains quite stable ahead of the front, but
increasing sfc convg could spawn a few general tstms east of the
mtns by late afternoon Sun. Another dry Canadian airmass mixes in Mon
and likely lingers into Tue, which will make for low RH values
during the afternoon periods. The next chance of precip will be Wed
as moist return flow ensues. Temps will pretty much remain arnd
normal levels each day.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Periodic restrictions will continue to plague
all terminals through the TAF period. Things start out complicated
early this morning with a mix of low stratus, high clouds and an
arcing band of showers moving towards the Upstate from Georgia that
could disrupt the formation of low stratus. A brief period of light
showers will be possible at KAND, KGMU, KGSP and KAVL as the band of
weakening showers moves in over the next several hours. This will
delay the onset of possible low stratus across the Upstate. Farther
east, at KHKY and KCLT, the band of showers shouldn`t have as much
of an influence with stratus possible earlier. Winds should keep fog
from being an issue tonight. What low stratus that does develop
should lift/scatter through the morning with VFR returning to all
terminals. Winds this afternoon will be gusty out of the southwest
ahead of an approaching cold front. Another round of showers and
thunderstorms will be possible this afternoon ahead of the frontal
boundary. Temporary visibility and ceiling restrictions can be
expected with any storms along with gusty winds out of the
northwest. Winds will shift to out of the north at KAVL by this
evening, but the wind shift will just outside of the TAF period for
the rest of the terminals.

Outlook: Drier air moves into the area by Friday morning with
improving conditions into the weekend. High pressure will linger
through Saturday before another system approaches by the start of
the new work week.

&&

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

&&

$$

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