614
FXUS62 KCHS 111724
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
124 PM 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/...
Radar imagery early this afternoon showed shower development
near upper Charleston county along the sea breeze. This trend
should continue as we move further into the afternoon with
convection potential largely focused over the Charleston tri-
county and especially near the Santee River.

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 /18Z THURSDAY THROUGH TUESDAY/...
Prevailing VFR through at least tonight. There is potential for
brief impacts from isolated/scattered showers and thunderstorms
at KCHS and KJZI this afternoon. Late tonight into Friday,
flight restrictions will be possible in MVFR ceilings and in
showers/thunderstorms again. Further south at KSAV, prevailing
VFR through 18z Friday. Low chance for restrictions in
showers/thunderstorms on Friday.

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...ETM/NED
MARINE...JRL/NED