Port Royal, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

081
FXUS62 KCHS 041447
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1047 AM EDT Fri Apr 4 2025

.SYNOPSIS...
Strong high pressure centered over the Atlantic will prevail
into this weekend. A cold front will push offshore Monday with
high pressure prevailing for much of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: An impressively strong and deep-layered anticyclone will
remain centered just off the Southeast Coast, leading to large-scale
subsidence and mostly dry/warm coniditons across the local area.
Southerly sfc winds along the western periphery of the sfc ridge
along with breaks in clouds (especially behind a developing sea
breeze) will allow for rapid warming. 1000-850mb thickness levels
support highs in the mid-upper 80s for most areas, but highs could
reach the lower 90s across inland areas of Southeast Georgia.
Although large-scale subsidence will keep most areas dry, a few
afternoon showers remain possible well inland where subsidence is
slightly weaker, PWATs remain in the 1-1.25 inch range, sfc heating
is stronger and SBCAPE approaches 2000 J/kg. Precip coverage should
remain isolated and rainfall accumulations on the lighter end given
the synoptic setup.

Tonight: With loss of insolation and the sea breeze having
cleared the entire region by around 8 PM, any isolated showers
early will have come to an end. There is little change in the
overall pattern surface and aloft, under the control of strong
deep-layered ridging. There`s a bit less moisture in the lower
levels, so the stratus/stratocumulus will not be quite as
extensive as recent nights. With less cloud cover expected, and
a little less wind in the boundary layer, lows are forecast to
be a tad lower than they were last night. We presently have
lower and middle 60s inland, with upper 60s closer to the coast.
But if winds are higher and/or cloud cover is more extensive (as
shown by some simulated satellite guidance), min temperatures
would be a bit warmer. Either way it`ll be far above climo. No
mention of fog just yet, but it does remain possible, especially
if stratus build down occurs.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Deep layered high pressure off the Southeast coast will continue to
hold influence over the local weather Saturday into Sunday. This
pattern will favor dry and warm conditions. Away from the beaches,
temperatures will peak around 10 degrees above climo with highs in
the mid to upper 80s, potentially touching 90 in spots. Lows will be
quite mild, only falling to the mid-upper 60s. These values are
within a couple degrees of daily record high minimums for April 6.
Otherwise, gusty south winds will develop each afternoon, especially
on Sunday ahead of an approaching cold front.

Mid level ridge will weaken Sunday night into Monday as a trough and
accompanying cold front shifts towards the East Coast. Airmass will
be juicy with models indicating PWats surging to near/over 1.75".
Given large scale forcing ascent, showers with embedded
thunderstorms are expected to spread across the area. While rain
chances will increase Sunday night, the bulk of activity is expected
to occur during the daylight hours on Monday. Strong wind fields
will be in place with deep layer shear increasing to over 50 knots
which could promote some storm organization, although instability is
not particularly impressive. Radar will certainly bear watching.
Temperatures will be tricky with incoming convection. Current high
temperature forecast spans the 70s, coolest inland.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A cold front and its associated rain chances will exit off the coast
Monday night. Dry and quiet weather is then expected through midweek
as high pressure returns. Most notably will be the drastic change in
temperatures. After the extended stretch of heat we will have
experienced, temperatures will drop back below climo. Overnight lows
are set to fall into the 40s both Tuesday night and Wednesday night.
Another cold front could approach late next week.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
KCHS/KJZI/KSAV: Flight restrictions will continue at all
terminals through the morning, generally down in the low-end
MVFR range. KCHS and KJZI will fluctuate between VFR and MVFR
based on recent satellite trends. It`ll take until 17Z before
VFR makes a return at all terminals. As mixing heights climb
during the late morning and this afternoon, S winds will gusts
frequently near 20 kt, before the gusts drop off with sunset.
Mixed signals regarding how much low cloud cover returns
tonight. For now kept it VFR, but flight restrictions are again
possible.

Extended Aviation Outlook: Gusty winds are expected on Sunday.
Flight restrictions are likely Monday as showers with a few tstms
impact the area ahead of a cold front.

&&

.MARINE...
Today and Tonight: Strong Atlantic high pressure will encompass the
local waters, leading to southeast/south winds around 15 kt or less.
The exception will be in Charleston Harbor, where sea breeze
influences generate some gusts around 20 kt this afternoon. Seas are
a mixture of swells and wind driven waves, equating to significant
wave heights of 3-4 ft within 20 nm of the coast, and 4-5 ft across
the outer Georgia waters. Guidance remains overdone on sea fog, as
it has been lately. Much of the guidance is initially showing sea
fog already occurring, when it is not. Winds are a bit too high for
its occurrence, so no mention is necessary in the forecast.

Saturday through Wednesday: Southerly flow will persist through the
weekend as the region remains on the backside of surface high
pressure. Speeds and seas will ramp up Saturday night into Sunday as
a cold front approaches the region, with conditions remaining
elevated into Monday. Small Craft Advisories could be needed. The
cold front will cross the waters later Monday, with flow turning
more northerly for Tuesday in its wake. Conditions are expected to
fall below Advisory criteria, although another brief surge is
possible Tuesday night into Wednesday as high pressure builds.

Rip Currents: Lingering 3 ft swells every 8 to 10 seconds will
support a moderate risk for rip currents for all beaches today
and Saturday. An elevated risk of rip currents will likely
persist into early next week.

&&

.CLIMATE...
Record High Temperatures:

April 5:
KSAV: 90/1988

April 6:
KSAV: 90/1967


Record High Minimum Temperatures:

April 3:
KCHS: 67/2012
KCXM: 68/2012
KSAV: 68/2012

April 4:
KCHS: 70/1974
KCXM: 69/1974
KSAV: 69/1974

April 5:
KCHS: 65/2017
KCXM: 67/2023
KSAV: 66/1957

April 6:
KCHS: 68/2023 KSAV: 68/2023

&&

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

&&

$$

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