Myrtle Beach, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

433
FXUS62 KILM 241045
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
645 AM EDT Tue Jun 24 2025

.SYNOPSIS...
Strong ridging aloft will build over the eastern United States
through midweek, with hot afternoon temperatures combined with
high humidity creating dangerous heat. Upper ridging starts to
break down Wednesday, with a weak upper low settling over the
South into next weekend. Typical afternoon storm coverage
returns on Wednesday and continues for the remainder of the
forecast period.

&&

.NEAR TERM /THROUGH TONIGHT/...
Deep ridging remains centered over eastern TN through tonight,
maintaining temperatures well above normal. Some of the
guidance, and the occasional CAM run, hint at a weakness in the
ridge dropping south-southwest across the area during the day
today. The brief reduction in subsidence within this area opens
the window for some isolated diurnal convection. The location of
this feature at the time of peak heating will determine which
areas see an afternoon shower or thunderstorm. There are some
hints of this feature on satellite, best seen on the water vapor
channels, and current motion would have the feature across
northeast SC by afternoon, with the sea breeze likely to be the
trigger. Not ruling out potential for a few storms in NC, again
along the sea breeze, but SC seems to be favored if current
motion/timing hold. This also meshes well with some of the 00Z
guidance, including some of the better performing (as of late)
CAMs.

Temperatures today will be tricky. The strong ridging will maintain
the heat, but the potential for cirrus of varying thickness this
afternoon and any isolated showers or thunderstorms and the
resulting debris cloud will have the potential to wreak havoc on the
temp forecast. There are 2 main camps within the 00Z guidance, some
have a full cirrus shield and some have no cirrus, there does not
appear to be any middle ground. Satellite imagery does show cirrus
to the northeast, off the Mid-Atlantic coast and this is on track to
reach the area this afternoon. Given the presence of this cloud did
take a little off the previous forecast highs. This does drop most
of the areas within the heat warning below warning below criteria,
but given the forecast uncertainty will maintain the warning even
though it looks a little less likely to verify than it did
previously. No changes planned for the heat advisory.

Forecast uncertainty continues tonight. Lows will be well above
normal, mid to upper 70s in many areas. The combination of very warm
lows and winds around 10 kt at the top of the boundary layer help
prevent fog development in most areas. The uncertainty comes from
potential for the remains of an MCS that some of the guidance brings
in from eastern VA close to daybreak Wed. Have added slight chance
pop for a few hours late in the forecast period along the northern
edge of the forecast area. If this feature develop across central
and eastern VA later today into this evening, the chances for
showers and possibly thunderstorms drifting south into the forecast
area will dramatically increase.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
An upper low working its way toward Florida will help to break
down a portion of the ridge on Wednesday. Weaker subsidence
aloft and a thermal trough across the central Carolinas should
allow for some scattered afternoon convection. This activity
will primarily exist along the inland trough with some isolated
storms possible earlier in the day along the sea breeze.
Remaining warm with temperatures in the mid 90s and heat indices
possibly sufficient for another heat advisory. Humid with
little relief overnight; lows in the mid 70s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Weak subsidence on the northern periphery of the upper low to
our south will limit storm coverage on Thursday and Friday.
Isolated storms will be likely focused along the inland Piedmont
trough with some stray activity possible along the sea breeze.
The low over the southeastern US will weaken this weekend and
what`s left of the distorted ridge will elongate over the
western Atlantic. Given the reduction in synoptic subsidence,
typical diurnal storm coverage should return this weekend with
near-normal temperatures.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
High confidence in VFR through the TAF period. Light and
variable winds this morning will increase and become onshore
for coastal terminals just after midday due to the sea breeze,
but speeds will be 10 kt or less. Isolated SHRA/TSRA remains a
possibility this afternoon with northeastern SC favored
slightly. Sea breeze will be inland of CRE/MYR before any cells
can develop with a similar story for ILM.

Light and variable to calm winds return this evening as the sea
breeze breaks down and any convection comes to an end, but not
expecting any fog development. Boundary layer winds do decrease
a bit, but the very warm temperatures make anything more than
patchy fog unlikely.

Extended Outlook... VFR with brief MVFR possible Wednesday
through Saturday afternoon.

&&

.MARINE...
Through Tonight... Gradient over the waters remains ill-defined
with light offshore flow this morning becoming southerly and
then more onshore this afternoon as the sea breeze circulation
develops. Speeds above 10 kt will be hard to come by today and
tonight, keeping seas 2 ft or less. Seas will be a mix of a weak
southerly wind wave and a weak southeast swell.

Wednesday through Saturday... A familiar summer forecast ahead.
Southwest flow returns on Wednesday with the re-establishment
of the Bermuda high. Seas will hover around 1-2 feet this week,
but should begin to increase on Friday as southeasterly swell
arrives. Seas increase to around 2-3 feet at 8-9 seconds for the
weekend.

&&

.CLIMATE...
June 24th Records
Climate Site            Forecast               Record
Wilmington, NC                97            99 (2024)
Florence, SC                 100           101 (2024)
Lumberton, NC                100           100 (2015)
North Myrtle Beach, SC        93            99 (1950)

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory until 10 AM EDT this morning for NCZ087-096-099-
     105-107-109.
     Extreme Heat Warning from 10 AM this morning to 8 PM EDT
     Wednesday for NCZ087-096-099-105-107-109.
     Heat Advisory from 10 AM this morning to 8 PM EDT Wednesday
     for NCZ106-108-110.
SC...Heat Advisory from 10 AM this morning to 8 PM EDT Wednesday
     for SCZ039-054>056.
     Heat Advisory until 8 PM EDT Wednesday for SCZ017-023-024-032-
     033-058-059.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...III
SHORT TERM...21
LONG TERM...21
AVIATION...III
MARINE...III/21
CLIMATE...ILM