195
FXUS62 KCHS 162331
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
731 PM EDT Fri May 16 2025

.SYNOPSIS...
Broad high pressure will persist through the weekend. A weak
cold front may push over the region early next week, remaining
generally stationary through Tuesday. A stronger cold front is
timed to sweep across the region Wednesday into Wednesday
night.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Early this evening: All is quiet as the sun sets on a very hot
day. We will continue to see some thin cirrus and a bit of mid-
level cloudiness pass through, but otherwise not much to talk
about. Radar imagery shows that the sea breeze remains pinned
along the GA coast, where it likely won`t make much inland push.
However, as you go up to the Charleston County coast the sea
breeze should reach Summerville soon and will continue to
progress inland. Expect another warm and muggy night, very
summer-like. Lows are expected to only dip to around 70 in most
areas.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Saturday: Possible chance of showers and thunderstorms in the
morning due to outflow from previous night`s storms in the Ohio
Valley. Some of the recent high res. guidance has been
indicating that some convection could reach the region by
~15-16Z and then quickly weaken over the area as we head into
the afternoon. Given the dry-air aloft and mid-lvl flow
weakening throughout the day, the severe potential with these
storms appears low. Expect highs in the low to mid 90s, and
overnight lows to dip into the upper 60s to low 70s (mid 70s
near the coastline).

Sunday: A wavy stationary front might linger over the region
throughout the day, as a MCS sourced from the Mid-Mississippi
Valley tracks closer, reaching the Lowcountry by the afternoon
(~18-19Z). There remains some uncertainty with this setup as
it`s largely dependent on the placement of the stationary front.
Recent runs of the NAM/ECMWF has kept the forecast rather dry,
while the GFS has been indicating that some type of disturbance
will possibly coincide with the afternoon seabreeze and allow
convection to develop in the afternoon. With the temperatures
relatively high and dewpoints in the low 70s, there just might
be enough instability for isolated to scattered showers and
thunderstorms to develop. By sunset, convection should track
offshore and temperatures will drop into the upper 60s to low
70s overnight. Given the possible rainfall in the afternoon,
patchy fog could develop overnight...however the forecast does
not include fog at this time.

Monday: Upper-lvl ridging from the Gulf will govern the overall
pattern on Monday, with heights gradually increasing throughout
the day. With mostly sunny conditions, highs will climb into
the low to mid 90s. A seabreeze will likely develop in the
afternoon and advance inland, thus it wouldn`t be a surprise to
see some isolated showers and thunderstorms develop along with
this.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Tuesday: The axis of the H5 ridge from the Gulf will continue
to dominate most of the region on Tuesday and allow highs to
reach into the low to mid 90s with upper 90s in SE Georgia.
These temperatures could definitely challenge the the record
temperatures, see climate section below. With hot and dry
conditions, thanks to the ridging aloft, any precipitation seems
unlikely and kept the forecast dry. Overnight, temperatures
will dip into the upper 60s to low 70s.

Wednesday through Friday: A strong upper- lvl low situated over
the Mid-west will continue to advance northeastward overhead,
as an associated cold front sweeps through the region on
Wednesday afternoon. With the support of a likely favorable
environment in the afternoon, severe thunderstorms on Wednesday
will definitely be possible. Some model guidance have already
started to hint of the development of something severe, however
uncertainty remains as this is still very far out in the
forecast. Moving on Thursday and Friday, this aforementioned
upper-lvl low will shift over New England and eventually off the
coast by the end of the week. Due to the passage of the cold
front, highs on Thursday and Friday will be slightly cooler than
previous days but will track just along normal for this time of
year.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected to prevail at KCHS, KJZI, and KSAV
through 00z Sunday. Winds will be breezy out of the west or
southwest beginning around midday Saturday and continuing
through the afternoon. Isolated thunderstorms are possible late
in the afternoon or early in the evening, but the chance of
direct impacts is too low to include anything in the TAF`s at
this point.

Extended Aviation Outlook: Some brief flight restrictions could
be possible on Sunday afternoon with the showers and
thunderstorms. Other than that, VFR conditions will persist.

&&

.MARINE...
Tonight: Southwest winds 10-15 kt will prevail with seas 2-3 ft.

Saturday through Wednesday: Ahead of the outflow boundary from
previous night`s weather in the Ohio Valley, south-
southwesterly winds could become a bit gusty on Saturday with
gusts approaching 25 kts in the afternoon. However, this remains
under Small Craft Advisory thresholds. Afterwards, Sunday
through Tuesday, high pressure will dominate over the Atlantic
waters and result in relatively calm southerly winds with an
increase in winds each afternoon associated with the seabreeze.
Moving on to Wednesday, a strong cold front is expected to pass
over the marine waters in the afternoon. Severe thunderstorms
may develop along this cold front and result in wind gusts well
over 25 kts. Generally seas will be 2 to 3 ft, then 3 to 4 ft
Wednesday. Small Craft Advisories will likely be needed for
Wednesday, however holding off for now until more guidance comes
in for this.

&&

.CLIMATE...
The high temperature for today at KCHS is 94, which ties the
daily record high for the date.

The high temperature for today at KSAV is 95, which ties the
daily record high for the date.

The low temperature observed so far today at KCHS is 72. If
this holds through 1 AM Saturday, this will establish a new
record high minimum for the date. The previous record was 71
last set in 2018.

Record High Temperatures:

May 17:
KCHS: 96/1963
KCXM: 94/1899
KSAV: 97/1899

May 18:
KSAV: 97/1899

May 19:
KSAV: 97/1996

May 20:
KSAV: 96/2006

Record High Minimum Temperatures:

May 17:
KCHS: 74/1995
KCXM: 75/1998
KSAV: 74/1995

May 18:
KCHS: 75/1995
KCXM: 77/1991
KSAV: 74/1899

May 19:
KSAV: 74/1930

May 20:
KCHS: 72/2022
KCXM: 76/2022
KSAV: 73/1896

May 21:
KCHS: 74/2022
KSAV: 74/2017

&&

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

&&

$$

NEAR TERM...BSH
SHORT TERM...
LONG TERM...
AVIATION...BSH
MARINE...