North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

579
FXUS62 KCHS 230717
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
317 AM EDT Sun Aug 23 2026

.WHAT HAS CHANGED...
All sections updated.

&&

.KEY MESSAGES...
- 1) Isolated to scattered showers and thunderstorms will be
  possible today and Monday. A few storms could be strong to
  severe.

- 2) Increasing rain chances mid to late week with the
  potential for locally heavy rainfall.

&&

.DISCUSSION...
KEY MESSAGE 1: Isolated to scattered showers and thunderstorms
will be possible Today and Monday. A few storms could be strong
to severe.

Well after a rather active afternoon with strong storms and
flash flooding, rain chances do look to decrease the next two
days as the upper trough shifts just a bit east. With the main
trough axis just east of the area; drier westerly to
northwesterly flow should begin to work into the area tonight
into tomorrow. This drier air in the mid-levels should help
limit coverage of showers and thunderstorms during the
afternoon. However, less storms does not always mean less
issues. While PWAT values will be lower in the 1.7 to 1.8 inch
range tomorrow, there should still be enough moisture in the
low levels to support some isolated to scattered storms to
develop along the afternoon seabreeze. With temperatures
climbing into the low 90s across SC and mid 90s across GA and
dewpoints behind the seabreeze in the 70s, instability will be
quite high in the 2,000 to 2500 range behind the seabreeze. What
storms that do form and cluster up to survive the drier air
could get rather strong. On-top of the instability, the
aforementioned drier air a loft could assist in downdraft
production leading to rather efficient downdrafts. DCAPE values
look to range in the 1200-1500 J/kg range behind the seabreeze,
which is rather potent. With 0-6km bulk wind difference around
20-25 knots, some multicellular organization could be possible
as storms slowly move towards the coast. Damaging winds will be
the primary threat with the strongest storms and as a result a
marginal risk (level 1 of 5) for severe weather is in effect for
today for most of the area. This potential is also noted in
some of the machine learning guidance that is hinting at some
low end threat for damaging winds.

Monday: Monday looks to be a rinse and repeat of Sunday with
rather similar conditions across the area. The only main
difference between Monday and Sunday will be slightly richer
moisture as an upper shortwave looks to pivot through the area.
This shortwave will help bring PWATs back into the 1.8 to 1.9
inch range which may support increased coverage across the area
and more clusters rather than isolated cells. Given the better
PWATS but drier air still lingering around some wet microburst
potential seems possible and would not be surprised if Monday
gets a bit rowdy in the late afternoon.

While overall concern the next two days for heavy rainfall is
lower given the lower moisture content, storms will still be
capable of heavy rainfall if they sit long enough over an area.
Given several locations are rather saturated after yesterdays
heavy rainfall and flooding, we will have to keep an eye on
where storms develop for any potential flooding issues.



KEY MESSAGE 2: Increasing rain chances mid to late week with
the potential for locally heavy rainfall.

By the mid part of the week, the upper trough will begin to
flatten out as upper ridging over the Atlantic begins to
strengthen. A series of embedded shortwaves are expected to
pivot through the upper trough Wednesday through Friday in very
much a repeat of the last couple of days. A subtle surface
boundary will slowly make its way into the area Wednesday
evening into Thursday. With deep southwesterly flow a loft,
PWATS are expected to climb back into the 1.9 to 2 inch range.
Between the seabreeze each afternoon, the slow moving boundary
and any remnant boundaries for each days storms, there should be
plenty of low level focus for scattered to widespread
thunderstorms to develop each afternoon. With PWATs approaching
2 inches and slow moving storm motions, heavy rainfall could
start to become an issue for some areas as rainfall totals could
quickly pile up. The biggest concerns likely come Thursday and
Friday as the surface boundary encroaches on the coast where it
will interact each afternoon with the seabreeze rather close to
the flood prone metro areas of Savannah and Charleston. We will
certainly have to keep an eye on this as we go throughout the
week.


&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR conditions should prevail tonight at all area terminals with
maybe some instances of MVFR ceilings west of I-95 during the
early morning hours. VFR conditions prevail into the afternoon
with isolated to scattered showers and thunderstorms developing
during the late afternoon. Storm chances look best along the
coast and as a result, PROB30 groups have been added to
CHS/JZI/SAV. Winds will remain light out of the southwest
turning slightly more southerly during the afternoon with the
passage of the seabreeze.

Extended Aviation Outlook: Prevailing VFR with isolated to
scattered showers and thunderstorms each afternoon potentially
bringing temporary restrictions to aviation.

&&

.MARINE...
Today through Friday: South to southwest winds will persist through
the period. Conditions will remain below Small Craft Advisory
levels, with winds averaging 15 knots or less and seas 2 to 3 feet.
Any showers or thunderstorms that move over the waters have the
potential to bring higher wind gusts and frequent lightning.

&&

.CLIMATE...

Record High Minimum Temperatures:

August 24:
KCHS: 76/2010
KCXM: 80/1975

August 25:
KCHS: 77/1982

August 28:
KCHS: 77/2020



&&

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

&&

$$

Black/ETM