Port Royal, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

362
FXUS62 KCHS 271149
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
749 AM EDT Fri Jun 27 2025

.SYNOPSIS...
High pressure will extend across the region through early next
week. A slow moving cold front may push over the area by the
middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a broad mid-upper lvl low will continue to
meander across the Southeast, primarily centered across Florida
and Georgia early day, but gradually nudging northwest with time
through the afternoon. At the sfc, the local area will remain
along the western periphery of an Atlantic high, with modest
troughing occurring along the eastern side of the Appalachian
Mountains well inland. The pattern will be quite similar to
conditions experienced the previous day, with h5 vort energy
associated with the upper low and an inland moving sea breeze
being the primary forcing contributors to few or perhaps
scattered showers and thunderstorms developing, but greatest
precip coverage should occur along and west of the I-95 corridor
across Southeast South Carolina into Southeast Georgia this
afternoon. A few stronger thunderstorms and/or an isolated
severe thunderstorm with damaging wind gusts can not be ruled
out along/near an inland moving sea breeze, mainly well inland
across Southeast Georgia mid-late afternoon, where SBCAPE around
2500 J/kg, low-lvl lapse rates around 8 C/km, and DCAPE near
800-1000 J/kg reside prior to the evening. However, weak shear/wind
fields suggest thunderstorms to remain pulse type in nature, and
likely waning and/or departing the local area well inland by
nightfall.

It will be another warm day, with ample sunshine and 1000-850 mb
thickness values supporting highs in the low-mid 90s away from
coastal areas. These temps in combination with sfc dewpts in the
upper 60s/lower 70s in warmest areas should produce heat index
values around 100 degrees, falling short of Heat Advisory criteria.

Tonight: Any shower/thunderstorm activity will likely have
diminished significantly and/or shifted further inland with a sea
breeze circulation and out of the local area by early evening,
leading to rather quiet/dry weather conditions for the remainder of
the night. Winds should decouple once again, leading to light/calm
winds away from the beaches for a bulk of the night. Temps will
remain similar to the previous night, with lows generally around 70
degrees inland to mid-upper 70s near the beaches.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Saturday: High pressure will dominate the mid-levels across the
western Atlantic Ocean and ArkLaTex. This setup places the local
forecast area within an area of relatively lower pressure aloft
between the two ridges. High pressure will dominate at the surface,
positioned over the western Atlantic Ocean. The circulation from the
high pressure will provide ample moisture, with PWAT values forecast
to be around 1.8" on Saturday afternoon. Between the moisture and
high temperatures in the low 90s, CAPE values are forecast to reach
between 1500-1800 J/kg. Scattered thunderstorms are possible over SE
SC with scattered to numerous thunderstorms over SE GA. The
thunderstorms will likely be focused around the inland pushing sea
breeze, mainly in the afternoon hours. Overnight lows are forecast
to only dip into the 70s.

Sunday and Monday: The upper level pattern remains unchanged,
however at the surface a broad trough begins to develop along the
southeastern coastline. PWAT values are forecast to reach 1.8", with
some models showing 2.0". Given the increased moisture and the
presence of the broad troughing at the surface, scattered to
numerous thunderstorms will be possible along the afternoon sea
breeze each day. High temperatures are forecast to reach into the
low to mid 90s with overnight lows in the 70s.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
On Tuesday a mid-level trough will be present over the Great Lakes
region, yielding broad troughing over the southeastern states. The
trough will shift eastward on Wednesday and finally ejecting off the
New England coast on Friday. At the surface a cold front will
approach the region on Wednesday, likely lingering in the vicinity
into Thursday. This will result in a more active weather pattern
with numerous to widespread thunderstorms in the afternoon hours.
Temperatures will be slightly cooler than the previous days, owing
to the increased precipitation, with highs in the upper 80s to
around 90.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through 12Z
Saturday. However, an isolated shower and/or thunderstorm could
impact any terminal early-mid afternoon, leading to TEMPO
flight restrictions. Probabilities remain too low to include in
the latest TAF issuance.

Extended Aviation Forecast: Diurnally driven showers and
thunderstorms could bring temporary flight restrictions through the
weekend and into next week, mainly in the afternoon hours.

&&

.MARINE...
Today and Tonight: Local waters will remain along the western
periphery of an Atlantic high while weak troughing develops well
inland. Conditions will remain below Small Craft Advisory thresholds
during this time frame, but a broad mid-upper lvl low could spawn a
few showers and thunderstorms across local waters during the day and
night, producing gusty winds and elevated seas. Outside convection,
southwest winds around 10 kt early morning will gradually turn
south/southeast and peak between 10-15 kt this afternoon, highest
near the coast where a sea breeze develops and shifts inland. Winds
should tip back more southwest by late evening, then remain in the
10-15 kt range, highest outside the Charleston Harbor during the
night. Seas will generally range between 1-2 ft today, then
gradually to 2-3 ft tonight.

Saturday through Tuesday: High pressure will prevail across the
marine waters through the weekend and into early next week, yielding
generally southerly flow 10 to 15 knots. Gusts along the direct
coastline could reach 20 knots each afternoon in association with
the afternoon sea breeze. Seas should average 2 to 3 ft through the
period.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...CPM
LONG TERM...CPM
AVIATION...CPM/DPB
MARINE...CPM/DPB