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206
FXUS62 KGSP 091846
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
246 PM EDT Sun Jun 9 2024

.SYNOPSIS...
A cold front moves south of our area becoming stationary through
mid week with dry conditions under weak high pressure for Monday
through Thursday.  Isolated to widely scattered showers and
thunderstorms are expected by next weekend as a weak cold front
approaches from the north.  Temperatures are expected to be well
above normal at end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
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Key Messages...

1) Strong to Severe Storms Possible Late this Afternoon into Early
this Evening

2) Widespread Rain is Expected to Develop Overnight into Early
Monday Morning

3) Dry Conditions Return Monday Afternoon

As of 245 PM EDT Sunday: Light rain has finally pushed east of the
forecast area and cloud cover has been gradually decreasing in
coverage east of the mountains this afternoon. Starting to see some
daytime cumulus develop east of the mountains thanks to better
insolation. Low-end gusts have developed across portions of the
forecast area this morning but these should taper off by the evening
hours. Since thick cloud cover lingered through the morning hours,
and with thicker clouds in place across the mountains currently,
this may act to limit high temperatures a bit today. However, it`s
still expected to be very warm east of the mountains with highs
climbing into the upper 80s and lower 90s. A cold front will push
across the forecast area late this afternoon into early this evening
allowing for thunderstorm development. 1000-1500 J/kg of SBCAPE has
already developed across the  western two-thirds of the area (the I-77
corridor remains fairly stable as cloud coverage is still lingering)
and 30-40 kts of deep shear is already in place area-wide. With the
rest of the forecast area expected to see up to 1500 J/kg of SBCAPE
later this afternoon, this should allow isolated strong to severe
thunderstorms to develop. The SPC Day 1 Severe Wx Outlook has the
majority of the forecast area in a Marginal Risk and this seems
reasonable. The main hazards with any severe storms that develop are
damaging wind gusts and large hail. Timing for severe wx looks to be
from roughly 5pm-9pm EDT.

A brief drying period is expected once the cold front pushes south
and east of the forecast area later this evening. Upper shortwaves
will track overhead the forecast area overnight into early Monday
morning allowing for widespread cloud cover and rain showers to
develop. Instability will be lacking so maintained no mention of
thunder overnight. Lows tonight will end up a few degrees above
climo thanks to both cloud cover and precip limiting radiational
cooling. Timing of the second wave of convection will be from
roughly 3am-9am. However, some isolated activity may linger across
the southern zones throughout the morning hours. Dry high pressure
will gradually build in from the west throughout Monday allowing dry
conditions to return by Monday afternoon. Temperatures will be much
cooler on Monday, around 2-4 degrees below climo, with highs only
reaching the low 80s east of the mtns.
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&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
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As of 205 PM EDT Sunday: Short waves drop across the area through
an upper trough on Tuesday. The trough moves east Wednesday with
weakening NW flow over our area. The cold front from the near term
slowly moves south away from the area Tuesday with dry high pressure
building in on Wednesday. Can`t rule out an isolated shower Monday
evening with lingering low level moisture and weak forcing, but
chance too low to include in the forecast for now. It will be breezy
Monday night and Tuesday though. Dry conditions and light winds
expected Wednesday. Below normal lows Monday night rise to near
normal Tuesday night. Near normal highs Tuesday rise a couple of
degrees above normal Wednesday.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
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As of 220 PM EDT Sunday: Still some run to run consistency issues
with the guidance. That said, there does seem to be a trend toward a
drier forecast. A series of weak short waves move through the flow,
mainly north of our area through Friday. Then a semblance of a Rex
Block develops Saturday into Sunday with an upper anti-cyclone
sliding into the Southeast by Sunday, and a weak upper low moving
east across the Gulf of Mexico. The result is weak and generally dry
high pressure Wednesday and Thursday with the potential for diurnal
convection Saturday as a weak cold front crosses the area. Diurnal
convection possible again Sunday as a moist southerly flow develops.
A warming trend takes place with highs nearly 10 degrees above
normal by Saturday, which drop back a few degrees for Sunday. Lows
rise to around 10 degrees above normal.
-- End Changed Discussion --

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Key Messages...

1) Thunderstorms Expected this Afternoon Ahead of a Cold Front

2) Widespread Rain expected Overnight into early Monday Morning

3) Cigs and Vsbys should generally range from MVFR to VFR through
the period

At KCLT and elsewhere: Light rain continues pushing east this
afternoon, with only isolated activity lingering along/near I-77.
Low-end gusts are noted at KAVL and KAND as of 18Z and KGSP and KGMU
could see gusts develop this afternoon as well. Gusts should
diminish by the early evening hours. Cloud cover is starting to
clear across portions of the terminals this afternoon which should
allow the atmosphere to become unstable. However, cloud cover will
gradually increase from west to east again, becoming BKN to OVC,
later this afternoon ahead of a cold front. The cold front will lead
to -SHRA/-TSRA late this afternoon into early this evening as it
tracks overhead. Have TEMPOs at all terminals, with the exception of
KAND which is expected to remain dry, to account for the convective
potential. Cigs should generally remain VFR outside of TSRA. Wind
direction remains W`ly east of the mtns this afternoon. Winds will
remain NW at KAVL through the TAF period, while winds east of the
mtns will turn N/NW behind the front this evening into tonight.
Brief drying is expected before a round of widespread showers tracks
across the terminals overnight into early Monday morning. Handled
this potential with PROB30s across all terminals. -SHRA should start
between 07Z and 09Z and push out between ~11Z and 13Z and should
allow cigs to fall to high-end MVFR levels, mainly across the SC
Upstate terminals. High pressure will build into the region
throughout Monday leading to much drier conditions and allowing VFR
cigs to gradually return. Cloud cover will gradually decrease
throughout Monday becoming FEW to SCT. Winds east of the mtns should
become more variable around daybreak Monday before turning WSW/SW
Monday afternoon.

Outlook: Dry sfc high pressure will linger through mid-week leading
to quieter weather.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...AR
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...AR