778
FXUS62 KCHS 131834
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
Issued by National Weather Service Columbia SC
234 PM EDT Tue May 13 2025

...HOT AND HUMID CONDITION POISED TO MAKE A RETURN TO THE SOUTH
CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA...

.SYNOPSIS...
Broad low pressure will drift north away from the region through
Wednesday. A ridge of high pressure will generally remain across
the area through the weekend, providing dry and hot conditions.

&&

.NEAR TERM /THROUGH TONIGHT/...
Through This Evening: GOES-E visible satellite imagery show the
cumulus field is becoming more agitated with time with isolated
convection beginning to pop as convective temperatures are
reached. Meanwhile, an area of scattered showers/tstms extending
from south-central Georgia into parts of Southeast Georgia
south of the Altamaha River will cross into parts of Candler,
Evans, Tattnall, Long and McIntosh Counties by mid-afternoon.
The greatest coverage of showers/tstms are still expected over
Southeast Georgia where the best 850 hPa theta-e is found. Pops
20-40% still look on target through the evening hours.
Thermodynamics are not overly supportive of severe weather, but
an isolated strong to marginally severe tstm can not be
completely ruled out, especially where updrafts can become
enhanced near mesoscale boundary interactions.

Overnight: The risk for an isolated shower/tstm will persist
through the overnight hours as weak shortwave embedded in the
broad cyclonic flow aloft passes through. Instability will be
waning as the night progresses, but there should be enough for a
tstm or two. Pops 20-30% were highlighted through the overnight
period. Lows will range from the mid 60s well inland to the
lower 70s at the beaches and Downtown Charleston.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Wednesday: A closed low situated over the Mid-west will
continue to slowly shift northeastward and gradually transition
into an elongated trough. Coming down to the surface, an
associated frontal boundary will meander well offshore over the
Atlantic waters. With cool mid-level temperatures and daytime
heating, scattered showers and thunderstorms are possible in the
afternoon with the sea breeze shifting onshore. Light south-
southwesterly flow will persist through the day with possible
becoming a bit gustier in the afternoon sea breeze. Highs are
forecast to be around normal with temperatures climbing into the
mid to upper 80s, and overnight lows in the mid to upper 60s
(with low 70s along the beaches).

Thursday and Friday: Finally this elongated trough will shift
off the Eastern Seaboard Thursday afternoon and allow for strong
upper- lvl ridging to build over the Deep South. At the
surface, high pressure should govern the overall pattern for
Thursday and Friday. Dry and quiet weather will settle over the
region and temperatures will be near average to above-average.
Highs will climb into the upper 80s to low 90s on Thursday and
low to mid 90s on Friday. Something to look out for .. with low
70s and high RH values, heat index values could reach just
around 100F on Friday afternoon making it feel quite unbearable
outside.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Upper-lvl ridging will govern the overall pattern for the
Southeast through the weekend, with zonal flow in place as well.
There is some indication of a shortwave trough traversing
through the zonal flow on Sunday. In general, it stays dry and
quiet through the weekend with possible showers returning on
Sunday evening ahead of an approaching frontal boundary.
Temperatures will be above average for this time of year, with
highs climbing into the low 90s. Combined with high RH values,
heat index values will reach into the mid to upper 90s through
the period ..making it feel very much like summer through the
period.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
13/18z TAF Discussion:
KCHS/KJZI: VFR. Isolated showers/tstms could develop around the
terminals from late afternoon through mid-evening, but
confidence on impacts is too low for a mention. Some shallow
ground fog could develop at both sites early Wednesday morning.
Again, no meaningful impacts are expected at this time.

KSAV: Convection is expected to move into/develop over interior
Southeast Georgia over the next few hours. Some of this activity
could get close to the KSAV airport. VCTS was highlighted 21-00z
to account for this. Some last minute adjustments may be needed
pending radar trends at issuance time. Otherwise, VFR will
prevail.

Extended Aviation Outlook: Brief flight restrictions are
possible on Wednesday with the aforementioned showers and
thunderstorms, otherwise prevailing VFR.

&&

.MARINE...
Tonight: Southwest winds will prevail tonight. Speeds will
average 10-15 kt with seas 2-4 ft.

Wednesday through Sunday: Conditions look to remain quite
through the period and well below Small Craft Advisory criteria.
South southwesterly flow should persist through the period with
winds generally 10 to 15 kts, or less. Seas will average 2 to 4
ft.

&&

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

&&

$$

NEAR TERM...ST
SHORT TERM...Dennis
LONG TERM...Dennis
AVIATION...Dennis
MARINE...Dennis/ST