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777
FXUS62 KGSP 050517
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
117 AM EDT Wed Jun 5 2024

.SYNOPSIS...
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Scattered showers and thunderstorms will develop this afternoon and
again on Thursday. Dry Canadian air will mix across the area Friday
and persist into the weekend. A chance of thunderstorms returns to
the region Sunday into Monday.
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&&

.NEAR TERM /THROUGH TODAY/...
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As of 114 AM Wednesday: A few lingering showers have been noted on
area radars, but most of yesterday`s convection has dissipated
and/or moved out of the area. A couple stray showers will likely
linger through the overnight, otherwise widespread low stratus
clouds and patchy fog will be common. Made minor tweaks to boost low
temperatures a degree or so and match up PoPs to the latest radar
trends.

Meanwhile, GSP finds itself beneath a weak upper ridge this
afternoon, with convection just firing up across the area.  The
synoptic setup will remain largely unchanged through the duration of
the near term, with the Carolinas ensconced in a strengthening warm
advective regime. Heights will fall ever-so-gently aloft in response
to a deepening upper low over Manitoba and peripheral shortwave
trough sliding up the central Ohio Valley.  As the localized ridge
axis drifts east of the area, high pressure over the west Atlantic
will intensify and drive ever more moisture into the forecast area.

Tonight, another round of fog is expected, for the mountain valleys
and for any locations that receive appreciable rainfall this
afternoon and evening.  Some light sprinkles may linger well into
the overnight, but should become less in coverage and intensity as
the night progresses.  Kind of like this morning, a few early
morning showers can be expected over the Upstate and southern NC
mountains Wednesday, but impacts are expected to be minimal.
The bulk of CAMs then depict another round of scattered showers
and thunderstorms tomorrow afternoon, in an environment of better
instability and synoptic support than today`s, but similarly
paltry shear.  Severe risk looks overall a little higher on
Wednesday compared to today, owing to the stronger forcing and
better instability.
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&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
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As of 105 AM Wednesday...The synoptic pattern has become more
progressive over the past couple model runs. There is now decent
agreement with a h5 s/w crossing the area before 18z Thu. Model
soundings during the afternoon look less impressive as the mlvls
warm and instability likely remains below 500 J/kg. There still
looks to be a chance of morning convec ahead of a sfc bndry, but
most of the storm activity will remain general in nature. A more
convectively suppressive environ builds in Fri as deep layered flow
becomes nw/ly and the column dries out. This drier air will persist
into the ext range and by Fri afternoon RH values will drop into the
30 percent range. Highs will likely increase a couple degrees abv
normal each day with increasing insol, while lows begin arnd normal
Thu night then fall below normal Fri night.
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&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
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As of 130 AM Wednesday...Made little changes to ext range fcst. The
guidance continues to depict a dry atmos in place over the weekend,
before a dynamic system pushes in Sun night into Mon. Broad surface
hipres will keep precip activity shunted west Sat, before a stg
upper low swings a cold front into the area Sun. This front looks to
lose upper support as it interacts with an existing flat ridge.
Profiles remain mostly stable each afternoon as a sfc bndry possibly
pushes thru the FA Sun night. The latest ECMWF is still an outlier
with stalling the front over or just south of the fcst area, which
would increase precip and thunder chances late in the period. For
now, will continue to advertise low chance PoPs Sun into Tue due to
uncertainty with the evolution of large scale pattern. Temps look to
remain arnd normal levels each day with low humidity values Sat
becoming more humid into the early next week.
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&&

.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
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At KCLT and elsewhere: Another pessimistic aviation forecast again
tonight with multiple rounds of restrictions expected at all
terminals through the TAF period. A few isolated showers continue to
hang on through the overnight hours, but coverage should be much
less compared to the last few evenings. The main overnight focus
will be the development of a widespread deck of low stratus with IFR
to LIFR ceilings. Patchy fog will also be possible. This thicker and
more widespread stratus will likely take longer to lift/scatter
after sunrise with restrictions forecast to continue well into the
morning hours with VFR returning by late morning to early afternoon.
Thereafter, another round of numerous to widespread showers and
thunderstorms is expected through the afternoon hours into the early
evening. As such, temporary visibility and ceiling restrictions can
be expected. Showers will likely linger into the evening with a
return to VFR.

Outlook: Yet another round of morning fog/stratus may occur Thursday
morning followed by more afternoon convection. Drier air moves into
the area Thursday night into Friday morning with improving
restrictions into the weekend.
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&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...MPR/TW
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...TW