066
FXUS62 KCHS 061848
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
248 PM EDT Tue Oct 6 2026

.WHAT HAS CHANGED...
All Key Messages and sections were updated.

&&

.KEY MESSAGES...
- 1) The risk for coastal flooding and significant coastal
  hazards continues.

- 2) Seasonable temperatures and generally dry conditions are
  expected through Thursday.

- 3) The National Hurricane Center (NHC) has identified a
  disturbance in the southwestern Gulf with a high chance of
  tropical cyclone formation during the next 48 hours.
  Regardless of development, heavy rainfall could develop over
  the Southeast United States by this weekend.

&&

.DISCUSSION...
KEY MESSAGE 1: The risk for coastal flooding and significant
coastal hazards continues.

Coastal Flooding: Strong northeast winds associated with a
wedge of high pressure inland and low pressure offshore in
combination with high astronomical tide levels will support
coastal flooding issues during high tide cycles through Thursday
and possibly into Friday. The tides of most concern will occur
during the late afternoon/early evening hours.

Charleston and Coastal Colleton Counties: Modest tidal
departures are occurring this afternoon with solid north to
northeast winds. Current trends and data support tides in the
Charleston Harbor will peak around 7.7 ft MLLW. There is still
about a 10% chance for tides to reach near the 8.0 ft MLLW
level, so trends are being monitored there. A Coastal Flood
Advisory is in effect from 3 PM and 8 PM. Impacts will be more
than normal at this tide given the highest tides will occur
during the afternoon rush hour and roadways will likely be
impassable at times, especially in the Downtown Charleston area
(Lockwood and Broad for example). Consideration was given to
upgrading to an impact-based Coastal Flood Warning, but the
decision was made to hold off until the tide gets closer to
7.8-7.9 ft given no meaningful rainfall is expected. This
afternoon`s high tide looks to be the highest of the next few
days, but the risk for minor to moderate coastal flooding will
persist into Thursday, possibly Friday.

Beaufort County, SC to McIntosh, GA County: Tides are expected
to peak in the 9.5-9.7 ft MLLW range at Fort Pulaski with the
late afternoon high tide. This will result in minor flooding
along much of the far lower South Carolina and middle/upper
Georgia coast. A Coastal Flood Advisory is in effect from 3 PM
to 8 PM, At these levels, water should not cross US-80 heading
to Tybee Island, but may still approach and even run-up onto the
road in spots. The backside of Tybee Island will be especially
vulnerable with some flooding likely to occur along some
roadways. This afternoon`s high tide looks to be the highest
of the week, but levels could still approach minor flood stage
around high tide Wednesday evening.

Rip Currents/High Surf/Beach Erosion: The setup remains highly
favorable rip currents into Wednesday with breezy/windy
northeast winds expected. A high risk remains in place for all
beaches through this evening. A high risk was highlighted for
the Georgia beaches with a moderate risk for the South Carolina
beaches for Wednesday. In addition, seas will build across
nearshore waters, with 4-7 ft breakers occurring in the surf
zone (largest along coastal Georgia) starting this afternoon and
persisting into Wednesday. A High Surf Advisory remains in
effect through early Wednesday afternoon along the entire coast
and could eventually need to be extended longer along Georgia
beaches into later Wednesday. Significant beach erosion is
likely with guidance suggesting highest chances for impacts
around the afternoon/early evening high tide cycle today.


KEY MESSAGE 2: Seasonable temperatures and generally dry
conditions are expected through Thursday.

Lake Winds: Observations at PNOS1 have been running in the
15-20 kt range out of the northeast for much of the day. The
sensor tends to under sample winds in northeast wind regimes
given the limited open fetch between the sensor and the
southeast side of Lake Moultrie. Winds may be diminish a bit
through mid-afternoon, but there are signals that a modest wind
surge will work across the coastal waters, Charleston Harbor
and Lake Moultrie during the early-mid evening hours as the
thermal gradient tights a bit with the loss of heating. For this
reason, a Lake Wind Advisory has been issued through 3 AM
Wednesday for frequent gusts around 25 kt with waves 2 ft.

Wednesday: The forecast area will remain between a stationary
front over FL and broad high pressure over the western
Carolinas. This pattern will support steady northeast winds,
speeds favoring values around 10 mph. Given dry and stable
northeast winds, conditions across SE GA and the SC Lowcountry
should remain dry. Latest HREF indicates a bit less cloud cover,
especially across inland GA and SC. With weaker NE winds and
increase insolation, high temperatures are forecast to range
around 80 degrees. Wednesday night, a weak pressure gradient
should provide light to calm winds. Scattered high clouds should
limit radiational cooling conditions overnight. Using a blend
of guidance, low temperatures are forecast to range from the low
50s inland to the low 60s along the coast.

Thursday: A weak cold front is forecast to slide over the Mid-
Atlantic states by late afternoon. Winds across the CWA should
remain fairly light and variable through the day. With dry
conditions anticipated, high temperatures may increase by 1 to 2
degrees over values observed on Wednesday.


KEY MESSAGE 3: The National Hurricane Center (NHC) has
identified a disturbance in the southwestern Gulf with a high
chance of tropical cyclone formation during the next 48 hours.
Regardless of development, heavy rainfall could develop over the
Southeast United States by this weekend.

Late this week, the H5 pattern will feature a broad closed low
over the Southern Plains and 595 DM ridge centered near Bermuda.
This pattern will gradually lift tropical moisture northward
across the Deep South and Southeast U.S. Friday through the
weekend. NHC has highlighted a broad area of low pressure,
invest AL92, located between Mexico and the Yucatan Peninsula in
their Tropical Weather Outlook. Invest AL92 has a high, near
100 percent, chance of formation during the next day or so as it
drifts eastward.

Friday into Saturday, moisture ahead of AL92 will push north
across the Deep South and Southeast U.S. as wedge of high
pressure builds across the Carolinas and Georgia. GFS forecast
soundings and overall pattern suggest that some degree of
instability will be present across the coastal counties of
GA/SC. The instability combined with strengthening isentropic
flow should support PoPs rising to categorical by Saturday
afternoon.

Saturday night through Sunday: The latest GFS and ECMWF and
especially the AI versions indicate a maximum of QPF within the
coastal trough Saturday night into Sunday. This rainfall would
be supported by strong isentropic lift and a building field of
SBCAPE, supporting thunderstorms. This could produce a quick
swath of significant rainfall, especially across the coastal
counties. In addition, New Moon high tides with elevated
astronomical tides will occur this weekend. Any elevated
rainfall rates during high tides may lead to flooding of
coastal areas, including Savannah and Charleston.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
06/18z:
KCHS/KJZI/KSAV: Patches of MVFR cigs have spread into the
terminals this afternoon. Expect mostly VFR conditions to
prevail for the much of the 18z TAF period, but a TEMPO group
was included for MVFR cigs for the next few hours. Gusty
northeast winds will persist into this evening.

Extended Aviation Outlook: VFR through late week. The risk for
flight restrictions returns over the weekend with increasing
chances for showers and/or thunderstorms.

&&

.MARINE...
Through Tonight: Winds are slowly increasing across the waters
this afternoon with gusts near gale force being observed at the
Charleston Pilot Buoy, the Fripp Nearshore Buoy and the
Savannah Light WeatherFlow sensor just off of Tybee Island.
These two sensors are where the area of highest winds are
expected to occur over the next few hours with gale force gusts
gradually spreading into the offshore waters. Gale Warnings
remain in effect for all nearshore and offshore legs with a
Small Craft Advisory in the Charleston Harbor. Buoy and Pilot
Boat reports indicate seas are already in the 5-9 ft range and
should remain here through tonight.

Wednesday: The pressure pattern will continue to produce gusty
northeast winds, with gusts between 25-30 kts across the
nearshore and outer waters. Winds may gradually decrease later
in the day. As a result, wave heights are forecast to begin the
day between 5-8 ft, then decrease by a foot through the rest of
the day. Small Craft criteria wind and sea should end Wednesday
night.

Thursday into Thursday night: High pressure will relax the
pressure gradient across the marine zones. Conditions should
remain well below Small Craft criteria.

Friday through Saturday: See NHC forecast for the latest on
invest AL92. The pressure gradient will increase between a
coastal trough and high pressure inland. Winds should strengthen
through the period, with gale wind gusts possible by Saturday.
Strengthening winds should drive sea higher, with 6-9 ft wave
heights possible on Saturday. Elevated conditions will likely
persist through the rest of the weekend.

&&

.EQUIPMENT...
The Metter, GA, NOAA Weather Radio Station (WWH-25) will be
offline from mid-morning Wednesday, October 7, through the
afternoon of Thursday, October 8. The transmitter is being
relocated.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through Wednesday evening for GAZ217-
     219-239-241.
     High Surf Advisory until 2 PM EDT Wednesday for GAZ217-219-239-
     241.
     Coastal Flood Advisory until 8 PM EDT this evening for GAZ217-
     219-239-241.
SC...High Surf Advisory until 2 PM EDT Wednesday for SCZ148>151.
     Coastal Flood Advisory until 8 PM EDT this evening for
     SCZ148>151.
     Lake Wind Advisory until 3 AM EDT Wednesday for SCZ045.
     High Risk for Rip Currents until 8 PM EDT this evening for
     SCZ148>151.
MARINE...Small Craft Advisory until 3 AM EDT Wednesday for AMZ340.
     Gale Warning until 8 PM EDT this evening for AMZ360-362-380.
     Gale Warning until 10 PM EDT this evening for AMZ364-382-384.

&&

$$