Area Forecast Discussion
Issued by NWS Charleston, SC

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
424
FXUS62 KCHS 150600
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
200 AM EDT Tue Jul 15 2025

.SYNOPSIS...
Atlantic high pressure will prevail through early next week.

&&

.NEAR TERM /THROUGH TODAY/...
Today: Aloft, ridging extending from the subtropical Atlantic
will stretch across the area just to the north of the upper low
associated with AL93. At the surface, the flow pattern across
the region will be driven by the circulation around AL93, but
then by the late afternoon the subtropical high will take hold
and the low- level flow will become more southeasterly with
time. This setup is quite different than yesterday and should
yield a much different evolution of convection. For the morning,
convection (thought most of it being showers) should occur
mostly along the coast and seemingly primarily along the SC
coast. Then into the afternoon under the influence of deep
layered easterly flow, showers and thunderstorms should shift
inland. Even still, model consensus is that the best corridor of
instability will reside further inland across central GA and
the SC Midlands. Overall coverage should be scattered across the
area with a low threat for severe storms. Model soundings show
less instability thanks to the onshore flow and warm profiles.
Also as a result of the onshore flow, highs are forecast to
mostly top out in the low 90s. This will also lower our heat
index potential today, with most locations topping out in the
low 100s.

Tonight: The evening should be pretty quiet with most of the
convection occurring well inland of the forecast area. An
occasional shower or storm over the coastal waters could try to
move onshore, but the coverage should be limited. Then late
tonight, the low-level flow will become more southeast and then
south-southeast. We should see an increase in shower and
thunderstorm activity across the waters, with trajectory of this
activity possibly making a run for the SC coast at times.
Otherwise, pretty quiet with lows in the low to mid 70s inland
and the upper 70s along the coast.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
Deep layered ridging will prevail mid to late week, maintaining
a typical July weather pattern. Scattered showers and
thunderstorms are expected each day, particularly in the
afternoon and early evening. A gradual warming trend will occur,
with highs in the lower 90s Wednesday, increasing to the mid
90s by Friday. Heat indices are currently forecast to remain
just below Heat Advisory criteria.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Toasty weather is in store for the weekend as the upper ridge
axis shifts overhead. Highs will reach the mid to upper 90s away
from the coast each day. Heat indices could approach 108F in a
few spots each afternoon. Scattered diurnal convection
anticipated, with a bit more coverage possible on Monday as the
upper ridge starts to break down.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
The 06z TAF period begins with VFR conditions at KCHS, KJZI,
and KSAV. Through sunrise, the main concern is the potential for
stratus to develop and spread into the KSAV area. Confidence
isn`t particularly high, but we have added in a TEMPO group for
MVFR ceilings from 11-13z which could also easily be IFR if it
indeed does occur. Concerning shower and thunderstorm chances
today, the best chances appear to be around KCHS and KJZI. This
activity and any potential impacts will likely begin this
morning and continue into the early afternoon. Thereafter,
showers and storms should shift inland and not be a significant
concern.

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: For the morning, the flow pattern along the
Southeast coast will be driven by the weak surface low moving
into the east coast of FL. Then by the afternoon and through the
overnight, the subtropical high will take control. We should
see widespread southeast flow across the local waters by early
afternoon which will then continue through the overnight. Wind
speeds today should top out as a solid 10-15 knots. Then
overnight, speeds will gradually increase to become 15 knots or
even 15-20 knots at times. Seas should average around 2 feet
through today, then increase to become 3-4 feet late tonight.
Showers and a few thunderstorms are expected across the coastal
waters and near the coast this morning, but this activity isn`t
expected to be particularly strong. Then through the afternoon,
focus for showers and storms should shift inland.

Moderate southerly flow will prevail Wednesday through Sunday.
A decent sea breeze will develop along the coast each afternoon.
Conditions expected to remain well below advisory criteria.

&&

.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