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FXUS62 KCHS 161155
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
755 AM EDT Thu Jul 16 2026

.WHAT HAS CHANGED...
Key Message 2 was added to address the minor coastal flooding
threat along the Charleston and Coastal Colleton coastlines with
this evening`s high tide.

&&

.KEY MESSAGES...
- 1) Hot and humid conditions are expected to return to the area
  today and persist through early next week. Heat Advisories
  could be needed.

- 2) Minor coastal flooding is possible along the Charleston and
  Coastal Colleton coastlines with this evening`s high tide.

&&

.DISCUSSION...
KEY MESSAGE 1: Hot and humid conditions are expected to return
to the area today and persist through early next week. Heat
Advisories could be needed.

Today: Weak ridging will develop across the Southeast United States
with a light westerly wind occurring across much of the local area
through the morning and into early afternoon hours. This should help
sfc temps warm into the mid 90s this afternoon, prior to a mid-late
afternoon sea breeze shifting inland. The light westerly wind along
with drier air depicted on model soundings aloft should help mix out
sfc dewpts into the low 70s inland, but a weak surge of sfc dewpts
(mid to upper 70s) is anticipated along/behind the sea breeze, which
could briefly result in heat index values reaching 105-108 degrees
across coastal zones. However, the duration/coverage of the warmest
heat index values should be short-lived, and afternoon convection
could further limit the spatial extent, keeping conditions just shy
of a Heat Advisory this afternoon.

Sfc high pressure will become more established across the western
Atlantic this weekend, favoring a southwest/south flow that brings
slightly higher dewpts across the local area. The combination of
temps in the mid-upper 90s along with elevated dewpts will yield
widespread heat index values above 100 degrees across Southeast
South Carolina and Southeast Georgia, and likely a swath of 108-112
heat index values for areas along and east of the I-95 corridor this
weekend, likely supporting Heat Advisories Friday afternoon and
possibly again Saturday afternoon. Next week looks to be warm and
humid as well with conditions approaching Heat Advisory level
conditions each day, but convective coverage could be more numerous
with an inland trough nearby Sunday into Monday, followed by the
approach of a front from the northwest heading to the middle of next
week.


KEY MESSAGE 2: Minor coastal flooding is possible along the
Charleston and Coastal Colleton coastlines with this evening`s
high tide.

The astronomical tide at the Charleston Harbor this evening will
be 6.2 ft MLLW. While this value is lower than the previous
nights which saw coastal flooding, guidance is showing that
departure values could approach 0.8 ft which would yield a tide
value right around 7.0 ft MLLW (minor coastal flooding). The
forecast has been updated to reflect a forecast of 7.0 ft MLLW
for this evening`s high tide around 11 PM. The need for a
Coastal Flood Advisory will be reevaluated later this
afternoon as confidence is not high enough at this time.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR conditions prevail at CHS/JZI terminals through tonight. At
SAV, VFR conditions should prevail through morning into early
afternoon hours today, but scattered showers and thunderstorms
could impact the terminal mid-late afternoon. A PROB30 group has
been introduced at SAV between 20-23Z for thunderstorms and
MVFR vsbys. By 00z, VFR conditions are likely to prevail through
06Z Thursday.

Extended Aviation Outlook: Mostly VFR. Low chances of direct impacts
from afternoon and evening showers and thunderstorms each day.

&&

.MARINE...
Today - Friday: South-southwesterly surface flow will develop today
and continue into Friday as a subtropical high develops, with winds
and seas expected to remain below Small Craft Advisory criteria.

Saturday - Sunday: Over the weekend, the surface pressure gradient
is expected to strengthen between an inland trough and the
aforementioned high to the east. This will produce stronger
southwest to south flow, with speeds getting more into the 15-20
knot range and an increasing chance of gusts up to 25 knots, mainly
for the SC coast and Charleston Harbor. We could even need some
short duration Small Craft Advisories over the weekend. 3 feet waves
are expected to develop along the coast, with 5 to 6 foot waves in
our outer offshore zones (highest in the zones 20-60nm out from
South Santee, SC to Savannah, GA).

Monday: The previously mentioned inland trough is expected to move
into the coastal corridor, continuing elevated winds with potential
for additional Small Craft Advisories. There is a low chance (20%)
for a low pressure system to develop/move into the region, which
would bring additional wind and wave concerns.

&&

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

&&

$$