Area Forecast Discussion
Issued by NWS Charleston, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KCHS 220212
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1012 PM EDT Mon May 21 2018

.SYNOPSIS...
The region will remain between Atlantic high pressure to the
east and broad low pressure to the west. This pattern should
support south winds through most of the week, yielding warm and
humid conditions.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Overnight, isolated/scattered showers will continue to push
through at least far southern/western counties. The degree of
north/eastward expansion of these showers, if any, remains
uncertain, and this will remain the primary focus of near term
forecast adjustments through the night. Where showers occur,
significant rainfall cannot be ruled out but appears unlikely
through the night.

Meanwhile, similar to Monday morning, expect areas of shallow
ground fog and patchy stratus to form overnight. There should
be enough high-level moisture to keep either from become too
dense/widespread. Low temps will range from the upper 60s
inland to the lower-mid 70s coast, beaches and downtown
Charleston.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Little change is expected in the large scale pattern through this
period. Models continue to keep the area situated between Atlantic
High Pressure to the east and lower pressure inland/west. With ample
deep layer moisture and afternoon heating, expect scattered to
numerous showers and isolated thunderstorms each afternoon. The
chance for thunderstorms to become stronger may increase Wednesday
and Thursday as models indicate higher values of instability/CAPE.
High temperatures will continue near to slightly above normal in the
mid 80s, and lows above normal in the upper 60s to lower 70s. With
afternoon dewpoint temperatures hovering around 70 to the lower 70s
each day, conditions will continue to feel a bit humid.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
High pressure pushing southeast from the Ohio Valley/Mid-Atlantic
region will combine with Atlantic high pressure as surface low
pressure tries to organize slightly in the central Gulf of Mexico.
The low should move toward the north-central Gulf coast and this
will continue to feed tropical moisture into the local area leading
to high rain chances especially each afternoon/evening. We continue
to discount the GFS which indicates a secondary low move north along
the Southeast U.S. coast as it remains an outlier. Temperatures
should stay near to above normal.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
00Z TAFs maintain VFR conditions. However, a low probability
exists for brief flight restrictions in patchy ground fog
and/or stratus later tonight/early Tuesday. Meanwhile, showers
could initially impact KSAV beginning late tonight/Tuesday
morning, and showers could then spread into KCHS as Tuesday
progresses. 00Z TAFs indicate VCSH at both sites.

Extended Aviation Outlook: Little change in the pattern is
expected through the work week, with Atlantic high pressure to
the east and lower pressure to the west/inland. This pattern,
along with sufficient deep layer moisture, will produce
scattered to numerous mainly afternoon showers and some
thunderstorms, which will result in the potential for brief
flight restrictions each day.

&&

.MARINE...
Overnight, ongoing forecasts remain on track. Expect S/SE winds
5-15 kt and seas 3-5 ft, highest beyond 20 nm.

Tuesday through Friday: No highlights. The marine area will
remain between Atlantic high pressure to the east and lower
pressure over the land. This will result in south- southeast
winds of 15 knots or less and seas 3 to 5 feet.

Saturday: Models continue to indicate the potential for a low
pressure system to develop in the Gulf of Mexico and move
northward. There is still great uncertainty with the track,
strength and potential for this system to become tropical.
Depending on the track and strength of the system, winds could
begin increasing from the southeast by Saturday, but too soon to
tell if Small Craft conditions or higher will be met. Stay
tuned to the latest Tropical Weather Outlooks from the National
Hurricane Center on the potential evolution of this system in
the Gulf of Mexico later this week and weekend.

&&

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

&&

$$
NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.