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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 111427
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1027 AM EDT Tue Aug 11 2020

.SYNOPSIS...
The region will remain positioned between Atlantic high
pressure well to the east and an inland area of broad low
pressure. A weak front could approach the area over the weekend
and linger in the vicinity into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
No significant change with the latest update, although did slow
down the increase in rain chances this afternoon given the
slower heating this morning due to abundant cloud cover. Still
some uncertainty regarding how much convection there will be
this afternoon as the upper trough/weak low shift more offshore.
The lazy sea breeze will be a trigger, possibly differential
heating boundaries as well, but not sure how much impact
convective boundaries will have. Storm motions will be weak and
deep moisture abundant so localized flooding could occur. A few
severe storms are possible as well but conditions do not appear
to be that supportive for much severe weather. Highs should be
in the lower to mid 90s away from the slightly cooler coastal
areas. Convection should dissipate this evening with the loss of
heating, with focus shifting offshore where the best
instability will be. Lows will generally be in the lower to mid
70s inland and upper 70s near the coast.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Surface high pressure will remain over the Atlantic through late
week, while troughing/broad low pressure persists inland. Aloft, a
weakness in the mid level ridge will linger off the Southeast coast.
A moist and unstable airmass will allow at least scattered showers
and thunderstorms to develop each day, with coverage peaking in the
afternoon and evenings. Some convection is possible overnight as
well, but the highest rain chances will generally shift to the
coastal waters. No particular day stands out for severe weather, but
a stronger storm or two can`t be ruled out especially where boundary
interactions occur. In addition, weak storm motions and high
moisture content could result in locally heavy rainfall. Otherwise,
temperatures will be within a few degrees of normal. Highs will top
out in the upper 80s/low 90s with lows overnight in the low to mid
70s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Models continue to lack consistency in the long term period. Broad
troughing aloft appears to shift towards the East Coast over the
weekend into early next week. At the surface, a weak front could
approach the region and then linger over or near the area. This
setup will generally favor higher than normal rain chances, although
given a good amount of disagreement between models, refinements will
be needed. Temperatures will be near climo.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR conditions expected to prevail through 12Z Wednesday.
Biggest challenge this TAF period is afternoon and evening
convection potential. Looks like greatest potential is from
around 19Z through 01Z, but anticipated coverage at this point
doesn`t warrant the inclusion of VCTS. This may need to be added
in a later forecast and there is the possibility of convection
at the terminals, especially during the 19Z to 01Z time window.

Extended Aviation Outlook: Flight restrictions possible in
showers/thunderstorms each day, mainly in the afternoon/evening.

&&

.MARINE...
-- Changed Discussion --
Today and Tonight: No significant concerns. Given a weak upper
trough across the area and a moist and unstable atmosphere,
evening convection over land tonight will likely transition to
the coastal waters where it looks like it will be an active
night across the waters. Most models show decent amount of
convection, so increased rain chances to higher level chance to
likely category. Outside of convection, it will be rather
tranquil with winds generally at or below 10 knots and seas 1 to
2 feet.

Wednesday through Sunday: No marine concerns expected through the
period outside of showers/thunderstorms. The waters will remain
positioned between high pressure to the east and broad low pressure
inland, allowing winds to maintain a southerly component. Speeds
will generally be 15 knots or less. Seas will average 2-3 feet.
-- End Changed Discussion --

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$
NEAR TERM...RJB
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...ETM/MTE
MARINE...ETM/RJB