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042
FXUS62 KGSP 190243
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1043 PM EDT Sat May 18 2024

.SYNOPSIS...
A weak low pressure system will track east across North Carlina
through tonight, bringing another round of showers and thunderstorms
to the area this evening and tonight. The low will exit off the
Carolina Coast on Sunday, with high pressure building in from the
north. Somewhat drier conditions return early next week resulting in
only isolated afternoon and evening showers and storms. A cold front
will bring better shower and thunderstorm chances back into the
forecast late in the week.

&&

.NEAR TERM /THROUGH SUNDAY/...
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As of 1045 PM Saturday: Ongoing convection developing in the
vicinity of the backdoor front is encroaching the NC/SC state line
and will continue to slowly shift southward. With the loss of
daytime heating, the severe threat is very low, but the hydro threat
remains as the storms anchor along the boundary underneath high PWAT
values. Otherwise, low stratus quickly filters in behind the front
and is evident via satellite imagery.

The mid/upper trof, positively tilted, is expected to move eastward
across the fcst area tonight. As this happens, we should see the
better mid/upper forcing slide to the east this evening. What we
lose at mid/upper levels we gain at low levels, so there should be
some organization moving in from the west this evening. However,
most of the CAMs weaken the convection to our west before it ever
gets here. We will just have to keep an eye on it, and particularly
the rainfall response. If the back door boundary makes it down
over Upstate SC, there could be enough low level convergence to
possibly anchor some storms near the Escarpment. Don`t think the
coverage of storms and duration will warrant any Flood Watch. Low
temps should remain about a category above normal.

On Sunday, the upper trof will gradually move off to the east. Drier
air moving down from the northeast will help to push the front
further down and south of the fcst area, so precip chances should
drop in the afternoon. The exception will be the mtns, as continued
low level easterly upslope will help to maintain showers and a
few storms. That flow regime should keep temps about five below
normal for the afternoon.
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&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 130 PM EDT Saturday: Mid level ridging and weak surface high
pressure will be in place across the region during the short range
period. This will lead to a general drying of the atmosphere and
lack of rainfall both Monday and Tuesday. The exception to this will
be over the favored high elevations where a shower or two will be
possible each afternoon during peak heating.

With the ridging and more sunshine in place, afternoon highs will
climb from the upper 70s in the mountain valleys and lower 80s in
the Piedmont on Monday to the lower to middle 80s respectively on
Tuesday. In other words, near climo on Monday and slightly above
climo on Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 140 PM EDT Saturday: Mid level ridging will remain in place
across the region for the middle of next week, but a weak trof
should weaken the ridge by the end of the week. High temperatures in
the Piedmont are expected to warm into the middle to upper 80s
through this period with lower to middle 80s expected in the mountain
valleys, all a few degrees above climo.

A more active convective pattern is expected toward the end of the
week with the breakdown of the ridge.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
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At KCLT and elsewhere: Lingering VFR/MVFR low clouds will continue
to fill in as ongoing thunderstorms moves from the CLT metro and
shifts southward through the evening hours. Included a TEMPO fo TSRA
and associated restrictions at all TAF sites, with the NC TAF sites
starting now through roughly 04Z, while the Upstate sites get in on
the action a little later (now-06Z). Winds will shift behind the
thunderstorms as a backdoor front moves in and shifts winds to a
north-northeasterly component. Winds will gradually pick up in speed
behind the front as well, which helps prevent widespread fog
development. Lingering showers overnight into the mid-morning hours
will mainly hover over the Upstate sites and KAVL, but will be
isolated in nature. Another player in the forecast is the low
stratus deck that will develop behind the front overnight. Have all
sites going IFR starting late this evening through mid-morning
Sunday before slowly lifting and scattering out by Sunday afternoon.
Can`t rule out LIFR cigs as well underneath the stratus deck at any
of the sites. Another round of showers and thunderstorms will be
possible across KAVL and maybe the Upstate sites, but confidence was
only high enough for a PROB30 mention at KAVL. Will have to watch
trends for the Upstate TAF sites by the 06Z update.

Outlook: SHRA/TSRA remain possible Sunday afternoon and perhaps
even Sunday night until stronger high pressure settles over the
region Monday. Late night/early morning restrictions in low stratus
and/or fog will remain possible Sunday night; isolated mountaintop
convection still appears possible Monday.
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&&

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

&&

$$

SYNOPSIS...SCW
NEAR TERM...CAC/PM
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...CAC