437
FXUS62 KCHS 140538
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
138 AM EDT Mon Jul 14 2025

.SYNOPSIS...
Atlantic high pressure will prevail into the upcoming weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, the upper ridge will be centered near the FL
panhandle and will extend into northern and western portions of
GA and the Carolinas. Also of note is the upper low just north
of the Bahamas and off the east coast of Florida. The forecast
area will sit between these features which will yield deep layer
north to northeast flow which is certainly not common. At the
surface, the developing lows off the east coast of FL will drive
the flow across the forecast area. Current thinking is that the
result of this northeast to easterly flow will result in a more
progressive sea breeze than we have seen the past few days with
the primary convergence zone setting up along and west of the
I-95 corridor. There is general agreement in the hi-res model
solutions that the best convective coverage will set up this
afternoon in this area. Also of note, this zone along and west
of I-95 will be where the deepest moisture will reside with
precipitable water values of 2 inches or higher. Coincident with
this, some relatively drier air will work in from the east with
precipitable water values approximately 1.7-1.9 inches along
and just inland of the southeast SC coast. Once again, the
severe threat does not look particularly noteworthy with
middling DCAPE values and certainly no support for anything
organized. But, the standard summertime disclaimer applies in
that where boundary interactions occur and enhance updrafts
there could be an isolated strong to marginally severe storm.
Locally heavy rain will be possible in this area along and west
of I-95 where the best moisture and storm coverage is expected.
A quick 1-2 inches will be possible in areas directly impacted
by storms but we do not anticipate any significant flooding
threat at this time.

Highs are forecast to mostly reach the low 90s along and east
of I-95, with mid to upper 90s west of I-95. We have again
lowered dewpoints a bit from the raw NBM by blending in the
NBM10, which seems to have worked out well yesterday and yielded
some more realistic heat index values. So for today we expect
to see heat indices max out around 105, and we should stay below
Heat Advisory criteria.

Tonight: Afternoon convection should gradually shift further
inland and off to the southwest through the evening. The rest of
the overnight should be dry for land areas, though we will
likely see increasing coverage over the coastal waters which
could draw close to the coast by daybreak. Look for lows in the
low to mid 70s inland and upper 70s along the coast.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
On Tuesday, the area will remain sandwiched between a weak
upper ridge over the northern Gulf Coast states and an expansive
upper ridge across the central and western Atlantic. Wednesday
into Thursday, the Atlantic ridge will expand into the
Southeast. And increase in mid-level subsidence during this
period should reduce the coverage of diurnal convection, though
with ample moisture and instability plus an active sea breeze,
we should still see scattered showers and tstms each day. Temps
will be near normal and heat indices are currently forecast to
fall short of Heat Advisory criteria.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Deep layered ridging will persist into the upcoming weekend.
Fairly typical July weather will continue with mainly scattered
diurnal convection each day.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
The 06z TAF period begins with VFR conditions at KCHS, KJZI,
and KSAV. Overall, it does not appear that there are any
significant concerns for fog and stratus through day break. Then
for afternoon and evening thunderstorm potential, the focus for
storms is expected to be further inland today. This means that
thunderstorm activity should remain inland of KCHS and KJZI.
KSAV will have a better chance of at least seeing a storm in the
vicinity and we have maintained VCTS starting at 21z.

Extended Aviation Outlook: VFR will mainly prevail throughout
the period, however brief flight restrictions are possible
within showers and thunderstorms that develop in the afternoon
and/or evening hours.

&&

.MARINE...
Today and tonight: The flow pattern across the local waters
will largely be driven by circulation around the developing area
of low pressure off the east coast of FL. This setup will drive
northeast to east-northeast flow, which could turn more east or
east-southeast for portions of the waters at times. Wind speeds
will remain on the weaker side, perhaps as high as 10-15 knot
at times. Seas should average around 2 feet through the period.
Thunderstorms do not appear to be as big of a threat this
afternoon and evening as most of the activity is expected to
remain inland of the coast.

Moderate southerly winds will continue Tuesday through Friday.
Speeds will generally be no higher than 15 kt and seas will run
2-4 ft. A decent sea breeze should occur each afternoon along
the coast, with a few gusts in Charleston Harbor approaching 20
kt.

&&

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

&&

$$

NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH/JRL
MARINE...BSH/JRL