North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

704
FXUS62 KCHS 122110
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
510 PM EDT Sun Jul 12 2026

.WHAT HAS CHANGED...
Updated Key Message #3.

&&

.KEY MESSAGES...
- 1) Showers and thunderstorms through Tuesday could produce
  locally heavy rainfall and isolated flooding. Some storms
  could also become strong to severe.

- 2) Hot and humid conditions will continue this afternoon, with
slightly cooler temperatures on Monday and Tuesday.

- 3) Minor coastal flooding is possible during the evening high tide
cycles today through Wednesday.

&&

.DISCUSSION...
KEY MESSAGE 1: Showers and thunderstorms through Tuesday could
produce locally heavy rainfall and isolated flooding. Some
storms could also become strong to severe.

Today and Tonight: Another rather active afternoon and evening
is on tap as upper ridging over the western Atlantic weakens and
upper troughing over the Ohio River Valley noses into the deep
south. Increasing west-southwesterly flow aloft and weakening
subsidence should provide an environment a little more suitable
for increased storm coverage this afternoon. Taking a look at
surface obs this morning and there appears to be a weak outflow
boundary draped west to east across the Tri county area and
downtown Charleston. Ongoing satellite imagery shows increased
cumulus development along this boundary and a couple isolated
thunderstorms already. With steady southwesterly flow, the seabreeze
will likely stay pinned close to the coast and by late this
afternoon I would expect the intersection of the seabreeze and
the aforementioned outflow to be the primary focus for storms
across the Charleston Metro (rather similar to yesterday).
Further to the west, storms will likely be ongoing across
central South Carolina into eastern Georgia. With slightly
increased mid-level to deep layer flow and rather impressive
deep moist profiles, storms will be capable of damaging winds
once again, especially if we can get storms to cluster up into
more multicellular clusters. Given the increased coverage and
potential for damaging winds across the area, a Slight Risk for
severe thunderstorms is in place for most of the our South
Carolina areas and a Marginal risk further south into eastern
Georgia where coverage may be a bit lower until later in the
evening when instability will be decreasing.

PWATS will be around 2 inches this afternoon and while deep
layer flow will be a little stronger than it has been the past
few days, storms will be capable of producing rather intense
rain rates around 2 to 3 inches per hour. As long as storms keep
moving than we should not have any flooding issues; however, if
storms linger around the wrong place too long (looking at you
Charleston and Savannah Metros) localized flash flooding would
be possible. Just based on this mornings analysis, if there were
an area of concern for flooding it would likely be along that
aforementioned outflow boundary near the Charleston Metro.
Especially given the potential for storms to train along that
boundary during high tide this evening leading to rather similar
flooding conditions to the previous two days across the metro.

Monday and Tuesday: A weak backdoor boundary/surface trough
stalling across the region early in the week should remain the
primary focus for shower and thunderstorm activity. Given
increased cloud cover and storm coverage over the early part of
the week, instability and severe potential should be lower than
the past couple of days; however, A few thunderstorms could
become strong to marginally severe each afternoon with damaging
winds being the primary concern. Given the low level focus for
storms and potentially a weak area of low pressure developing
along this boundary, a more confined area of heavy rainfall
could become of concern if the rainfall totals begin to pile up
with multiple days of rain. The latest SPC Day 2 Convective
Outlook advertises a Marginal Risk for severe weather across the
entire area Monday while WPC highlights the entire area in
Marginal Risk for excessive rainfall Monday and Tuesday.

KEY MESSAGE 2: Hot and humid conditions will continue this
afternoon, with slightly cooler temperatures on Monday and
Tuesday.

As a hot, humid airmass remains across the Southeast, expect
temperatures to continue to rise into the mid to upper 90s through
the afternoon before showers and thunderstorms initiate off the
seabreeze as it pushes inland. Expect dewpoints to be highest along
the immediate coastline and up into the Charleston Tri-County as
values reach into the upper 70s, resulting in peak heat index values
near 110F. Inland areas will have slightly lower heat index values
with dewpoints in the lower 70s. Therefore, a Heat Advisory remains
in effect across southeast Georgia and southeast South Carolina
coastal counties, Tidal Berkeley, and Inland Berkeley until 7PM EDT.

Monday and Tuesday: A weak cold front will push through on Monday,
allowing for slightly cooler air to advect into the region.
Thereafter, the front will remain just south of the region into
Tuesday. This will yield increased cloud coverage and rainfall.
Afternoon temperatures will only reach into the upper 80s to lower
90s for Monday and Tuesday. Heat index values will peak into the low
to mid 90s across the inland counties, with values peaking into the
upper 90s to lower 100s.

These slightly cooler temperatures will be short-lived unfortunately
as H500 heights begin to rise again on Wednesday as a ridge
strengthens aloft. Expect temperatures to rise back up into the low
90s on Wednesday, then further climbing into the mid to upper 90s on
Thursday and Friday.

KEY MESSAGE 3: Minor coastal flooding is possible during the evening
high tide cycles today through Wednesday.

Increasing astronomical tides associated with Monday`s lunar perigee
and Tuesday`s New Moon will bring a risk of minor coastal flooding
starting this evening. This evening`s high tide (~7PM EDT) at the
Charleston Harbor (CHTS1) is forecasted to reach 6.9 ft MLLW.
This will be just shy of reaching Coastal Flood Advisory
criteria (7.0 ft MLLW). Therefore, a Coastal Flood Advisory
deems not likely this evening, however conditions will continued
to be closely monitored.

However, the greatest threat is expected Monday and Tuesday evening
as astronomical tides continue to increase, mainly along the coastal
Charleston and coastal Colleton Counties. Additionally, heavy
rainfall occurring near, or during the time of the evening high tide
cycles could exacerbate flooding.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR conditions should prevail across the area through early
afternoon; however, satellite and radar observations already
show thunderstorm activity starting to pickup in and around the
CHS/JZI terminals. Shower/thunderstorm chances will increase
over the next couple of hours especially near CHS and JZI where
the greatest risk for thunderstorms will likely be. Gusty winds
and temporary reductions in vsbys/ceilings will be possible
within the strongest of storms. Coverage during the afternoon is
not as widespread further south towards SAV; however, similar
impacts are possible at SAV as we head into the early evening
hours around 00Z. Conditions should gradually improve at CHS/JZI
by early evening with only some lingering showers through
around 04Z and slightly later for SAV given the later increase
in storms. VFR conditions should then return at all terminals by
around 04Z Monday, then persist through 18Z Monday. Some MVFR
ceilings may try to work into the area early 12-18z Monday
morning but it does appear to stay north of any of the aviation
sites.

Extended Aviation Outlook: Shower and thunderstorm coverage,
along with risks of associated restrictions, will remain
elevated through Tuesday.

&&

.MARINE...
This afternoon through Thursday: Ahead of a weak cold front, expect
breezy southwesterly winds to persist as the seabreeze pushes ashore
this afternoon. Similar to the previous couple days, expect
afternoon thunderstorms to initiate off the seabreeze and likely
bring a risk of strong winds. As this aforementioned weak cold front
gradually settles across the South Carolina waters on Monday night
into Tuesday morning, this will yield variable winds over the next
couple days. This change of pattern will also yield scattered
showers and thunderstorms across the coastal waters through Tuesday.
A few storms will be capable of producing strong to severe wind
gusts, frequent lightning, and locally higher seas. Otherwise,
marine conditions remain under Small Craft Advisory criteria.

Rip Currents: A moderate risk for rip currents will remain from the
South Santee River down to Savannah through this evening, due to 1-2
ft swells with wave periods up to 9 seconds along with increasing
tidal influences from the upcoming lunar perigee on Monday. In
addition, SSW winds will likely generate a moderate longshore
current, possibly supporting rip currents near piers and
jetties.

&&

.CLIMATE...
Record High Minimum Temperatures:

July 12:
KCHS: 79/2020

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory until 7 PM EDT this evening for GAZ217>219-
     239>241.
SC...Heat Advisory until 7 PM EDT this evening for SCZ045-148>152.
MARINE...None.

&&

$$

Black/Dennis