425
FXUS62 KCHS 111424
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1024 AM EDT Thu Jul 11 2024

.SYNOPSIS...
A weak front will meander across the area through Saturday.
Atlantic high pressure will then rebuild across the area while
a surface trough exists inland Sunday through the middle of
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold front has now passed offshore, but it is forecast to transition
back westward towards the coast and onshore as a weak warm
front later today and tonight. Aloft, weak ridging extends
across the Southeast in between a trough to the northwest and a
low over the Atlantic. Guidance is pretty consistent that
isolated to scattered showers and thunderstorms will develop
east of the front this afternoon as instability increases and
deeper moisture returns. Focus for convection largely looks over
the northern zones and near the Santee River.

High temperatures are forecast to generally range in the mid 90s
this afternoon inland from the beaches. Coastal temperatures should
peak in the upper 80s to low 90s. Heat index values are forecast to
range between 100-105 degrees along and east of I-95. Tonight, low
temperatures are forecast to range from the low 70s inland to the
upper 70s across the coastal counties.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
A weak surface low will be over southeast GA Friday morning,
drifting slowly west while dissipating during the day. A subtle
boundary associated with the low may remain draped across
southern SC for much of the day. A decent moisture gradient will
persist across the area, with somewhat drier air remaining over
southeast GA while >2" PWATs spread into southern SC. There
should also be a solid afternoon sea breeze pushing inland.
Scattered convection possible anywhere, though better coverage
is expected over southern SC. Convection may persist well into
Friday night, particularly over southern SC.

Upper ridging will occur Saturday into Sunday, though some
models show shortwave energy moving into the area later Sunday
afternoon. A weak surface boundary is expected to linger across
southern SC on Saturday before dissipating, potentially aiding
convective development. Despite the relative lack of pronounced
weather features, there should be ample moisture and forcing
for at least scattered showers and thunderstorms both days. We
still show slightly greater coverage over southern SC on
Saturday.

The upper ridging will result in gradually warming temperatures
during the period. Surface dewpoints will remain in the upper
70s across the southeastern half of the forecast area for much
of the period. Heat indices are progged to climb above 108
degrees in this area both Saturday and Sunday. Heat Advisories
are relatively likely both days.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Broad upper ridging will persist early next week, though a few
shortwaves will ripple through at times. Atlantic high pressure
will build to the east while a surface trough persists just
inland. At least scattered mainly diurnal convection expected.
High temps warming into the upper 90s next week, combined with
juicy dewpoints, will likely result in heat indices above 108 in
parts of the area. We could even be approaching Excessive Heat
Warning criteria (113F) Tuesday and Wednesday.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
Prior to the 12Z TAFs, a weak cold front pushed across the
terminals, turning winds from the NW. The front will become
nearly stationary along the coast this morning. An area of low
pressure is expected to develop off the Southeast U.S. coast
today. The circulation around the is expected to push a warm
front / sea breeze inland from the coast, better defined north
of the Santee River. Scattered showers and thunderstorms should
develop near the warm front this afternoon into this evening.
Confidence is too low to mention SHRA/TSRA at KCHS/KJZI this PM.
However, TAFs will indicate that winds will turn from the
southeast by mid to late afternoon.

Extended Aviation Outlook: Scattered showers and thunderstorms
could produce brief flight restrictions each afternoon.

&&

.MARINE...
Today: A cold front has pushed offshore this morning. The
circulation around an area of broad low pressure over the
western Atlantic is expected to push the front back inland as a
weak warm front this afternoon. Winds across the marine zones
should shift from the SE between 5 to 10 kts this afternoon.
Seas are forecast to range between 1 to 3 ft today.

Friday through Monday, southerly flow will persist with no
headlines expected. The gradient will tighten slightly early
next week as Atlantic high pressure strengthens to our east
while a potent trough exists inland. Sustained winds could
occasionally be close to 15 kt as opposed to the typical 10-15
kt of flow. Seas will range from 2-4 ft through the period.

&&

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

&&

$$

NEAR TERM...ETM/NED
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...JRL/NED
MARINE...JRL/NED