348
FXUS62 KCHS 020015
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
815 PM EDT Mon Jul 1 2024

.SYNOPSIS...
A cold front will impact the area tonight into early Tuesday
before dissipating offshore. A hot and humid air mass will
build over the region during the latter half of the week. By
Monday, a weak cold front may reach coastal Georgia and South
Carolina.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Another forecast update to cancel the rest of the Flood Watch.
Ongoing convection is mainly in just scattered clusters where
heavy rainfall will be localized and any resulting flooding
issues should be minor. Also, these storms are progressive
enough to prevent enough duration to produce flash flooding.

Thunderstorm activity continues to concentrate along the
southward moving front/outflow boundary. This aligns convection
from the South Carolina coastal waters westward across Beaufort
and Jasper counties, back into interior southeast Georgia.
Activity will likely continue to develop along the front/outflow
until it gets to the Altamaha River and further south.
Precipitable water values are still quite high, around 2.1-2.4
inches, which will support a locally heavy rainfall threat. We
have adjusted rain chances to depict the highest chances across
the coastal waters and then along the Savannah River and points
westward. There does not appear to be any real severe weather
threat, though the outflow boundary and front could produce wind
gusts into the 25-30 mph range as it passes.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Tuesday: The surface pattern is expected to feature a stalled
boundary across SE GA with drier high pressure ridging across
the SC Lowcountry. The environment along and south of the front
should continue to feature deep instability and PW. The forecast
will feature scattered to numerous showers and thunderstorms
along and south of the front, keeping portions of inland SC dry.
Using a blend of MOS, high temperatures are forecast to range
in the mid to upper 80s.

Wednesday: Short term guidance indicates that a 595 dm ridge
will build over the Deep South and Southeast CONUS. At the sfc,
the center of high pressure will remain off the NE and middle
Atlantic states, resulting in ENE flow across the forecast area.
This pattern will support a sea breeze to develop, serving as a
focus for deep convection. Given the wide field of instability,
scattered to numerous showers and thunderstorms are forecast to
develop along the sea breeze. High temperatures are forecast to
range around 90 degrees. A few counties across extreme SE GA
may see heat index values peak between 100-105 degrees.

Independence Day: Mid-level ridge will build over the forecast
area on Thursday. Given high pressure over the western Atlantic,
a sea breeze may develop during the afternoon. However, GFS
forecast soundings indicate drier conditions compared to the
first half of the week. Forecast soundings indicate PW around
1.5 inches with an inversion centered at H65. This profile
indicates limited instability. The forecast will indicated
isolated showers and thunderstorms. High temperatures are
forecast to range between 90-95 degrees over dewpoints in the
low to mid 70s. Heat index values are forecast to peak between
100-105 degrees.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Friday through Sunday, the feature of concern will remain the
595 dm ridge over the region. The forecast area under the strong
ridge will feature high temperatures in the mid to upper 90s
each day. In addition, dewpoints will climb in the mid to upper
70s. The max heat index will range between 105 to 113 each
afternoon. This may result in either a Heat Advisory or a
Excessive Heat Warning late this week into early next week. The
forecast will indicate diurnal isolated to scattered showers and
thunderstorms each day.

On Monday, a weak front will approach from the west as the mid-
level ridge shifts over the western Atlantic. Conditions across
the forecast area will remain hot. However, storm coverage
should increase, bringing some relief from the heat.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
For the 00z TAF period, thunderstorm activity has ended near
KCHS and KJZI, while the next round of storms around KSAV should
occur over the next couple of hours. First at KSAV, we advertise
IFR visibilities in TSRA with a TEMPO group from 01-03z.
Thereafter, model guidance suggests MVFR ceilings should spread
across the terminals for much of the overnight period. While we
can`t rule out a period of IFR ceilings, confidence is highest
in MVFR conditions. Late tonight, showers and thunderstorms
could develop along a stalled boundary just off the Beaufort
County coast. This activity could try to push inland and
approach KSAV Tuesday morning. Showers and thunderstorms should
stay south of KCHS and KJZI on Tuesday, while chances of direct
impacts will be higher at KSAV.

Extended Aviation Outlook: Brief flight restrictions are
possible in showers and thunderstorms, mainly in the afternoon
and evenings through the period.

&&

.MARINE...
Tonight: A cold front will work slowly south into the waters
tonight. Winds will shift to the northeast behind the front with
speeds reaching 15-20 kt in the South Santee-Edisto Beach
nearshore leg late. Otherwise, winds speeds will remain 15 kt or
less. Widespread showers/tstms could reduce vsbys to 1 NM or
less at times. A few strong convective wind gusts in excess of
35 kt could also occur. Seas will average 2-4 ft.

Tuesday through Saturday: Gusty ENE winds should develop across
the nearshore SC waters on Tuesday. The region will remain
between building high pressure and the front stalled to the
south. Gusts are forecast to remain around 20 kts with 3-4 ft
seas. Conditions are forecast to remain below Small Craft
Advisory criteria through the rest of the week. A weak pressure
gradient should support winds 15 knots or less and seas
averaging 2-3 ft.

&&

.CLIMATE...
Daily Rainfall Records for July 1:
KCHS: 2.66 set in 1948
KCXM: 1.64 set in 1966 (*As of 8pm, 1.93 has fallen today*)
KSAV: 2.76 set in 1871

&&

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

&&

$$

NEAR TERM...BSH
SHORT TERM...NED
LONG TERM...NED
AVIATION...BSH
MARINE...