755
FXUS62 KCHS 161419
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1019 AM EDT Fri Aug 16 2024

.SYNOPSIS...
High pressure will remain over the area through the weekend. A
cold front will push across the area early next week, then
remain nearby through late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
The morning composite analysis reveals upper level ridging
stretching from the eastern Great Lakes to the Gulf coast and
surface high pressure draped along the entire east coast...with
Hurricane Ernesto around 850 miles off the southeast coast
moving northeastward toward Bermuda.

Upper level ridging and surface high pressure will remain in
control of our weather through tonight, maintaining our slightly
cooler and less humid conditions. The forecast soundings show
strong mid-level capping/(CINH) and PWat just 70-80% of normal.
Thus, the forecast will continue to advertise quiet weather
through tonight.

Highs today will run just a touch warmer than Thursday...87-91F
with cooler readings along the coast. Lows tonight will run
from the upper 60s to lower 70s, warmer along the coast.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Saturday: At the sfc, high pressure will remain along the coast
through the day. Given light south winds, dewpoints may increase to
around 70 degrees during the afternoon. However, a lingering H7
inversion should provide enough of a capping inversion to limit
convection. A rogue shower is not completely out of the realm of
possibilities, but guidance consensus favors dry conditions. The
current forecast reflects a 10-15% chance of precipitation. High
temperatures will reach the low 90s away from the coast and
overnight lows will range in the low to mid 70s.

Sunday and Monday: A cold front will slowly approach from the west
through the day Sunday. The sea breeze is expected to drift inland
during the mid to late afternoon, resulting in dewpoints to climb
into the mid 70s. A broad area of deeper moisture will push across
the area ahead of the front Sunday. Isolated to scattered showers
and thunderstorms are forecast to develop between the sea breeze and
the approaching cold front. The greatest coverage looks to occur
late Sunday into Monday as a large upper trough digs into the
Southeast which will provide enhancement of lifting mechanisms. The
cold front is currently timed to reach the Atlantic coast Monday
morning. Guidance indicates that the environment along and ahead of
the cold front will feature CAPE around 2000 J/kg and 0-6 km shear
around 30 kts. This environment could support a few organized storm
clusters or lines, resulting in strong to severe thunderstorms
capable of producing damaging wind gusts. It is possible that a
couple of severe storms could occur late Sunday night, beyond
midnight. The rest of the day Monday should remain mostly dry behind
the front. High temperatures are forecast to range in the low to mid
90s Sunday. On Monday, highs should be a few degrees less than
Sunday due to the (likely) passage of the front.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
Aloft, the large trough extending from extreme eastern Canada down
to the Florida Keys will sit nearly stationary through the middle of
next week. The sfc pattern will feature building high pressure to
the north as the cold front becomes stationary off the coast. This
pattern should yield light east winds, allowing a sea breeze to
develop each afternoon. Isolated to scattered showers and
thunderstorms could develop during the afternoon and evening hours.
High temperatures should range near normal each day; in the mid to
upper 80s.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR conditions are expected to prevail at KCHS/KJZI/KSAV
terminals through 12Z Saturday.

Extended Aviation Outlook: A cold front is forecast to impact the
region late this weekend/early next week, bringing the risk of brief
flight restrictions within showers and thunderstorms.

&&

.MARINE...
Long period swell energy from Hurricane Ernesto will increase
across the coastal waters today with seas building to 4-6 ft
across the nearshore waters, 5-7 ft across the outer GA waters.
Small Craft Advisories have been issued for the outer GA waters
and the South Carolina nearshore waters accordingly.

Otherwise, east to northeast winds between 5-10 kts are expected
today, becoming light Friday night.

Saturday through Wednesday: Seas should decrease to 3-5 ft with
light and variable winds early Saturday with high pressure in place.
Saturday night into Sunday winds and seas will gradually increase
ahead of an approaching cold front that is expected to push across
the local waters Monday. Winds could surge from the SW to around 20
kts with gusts 20-25 kt Sunday night. In addition, sea could build
to around 6ft across portions of the outer GA waters Sunday.
Conditions will improve throughout the day Monday with seas dropping
to 2-3 ft, and winds shifting out the north around 10-15 kt for
Tuesday and Wednesday.

High Surf: Long period swell and seas building to 6 feet or
better might lead to breaker heights approaching 5 feet along
the South Carolina coast later today into tonight. Recent
webcams along the coast showing breakers around 3 feet, with an
occasional 4 footer. No High Surf Advisory planned at this
time, but we`ll continue to monitor.

Rip Currents: Long period swell (13 to 15 seconds) from
Hurricane Ernesto have reached the forecast area and will
continue to impact the southeast coast through the weekend.
This will produce a high risk of rip currents at all area
beaches today and again Saturday. The threat for rip currents
could persist into Sunday as well.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents until 8 PM EDT this evening for GAZ117-
     119-139-141.
SC...High Risk for Rip Currents until 8 PM EDT this evening for
     SCZ048>051.
MARINE...Small Craft Advisory from 4 PM this afternoon to 8 AM EDT
     Saturday for AMZ350-352.
     Small Craft Advisory until 8 AM EDT Saturday for AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...BRM
LONG TERM...BRM
AVIATION...Adam/BRM
MARINE...