Myrtle Beach, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

583
FXUS62 KILM 112048
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
448 PM EDT Fri Apr 11 2025

.SYNOPSIS...
High pressure will build in behind an offshore cold front. It
will usher in dry and slightly cool air for the weekend. A
warmup Monday will be reversed by a weak cold front Tuesday.
Temperatures will climb towards the end of the week ahead of
another cold front.

&&

.NEAR TERM /THROUGH SATURDAY/...
Latest surface analysis shows one cold front just offshore of the
coastal Carolinas, while another front is exiting Appalachia and
pushing into the Carolina Piedmont. Latest GOES-16 visible satellite
feeds show some good spin around the upper low at 850mb. Some
considerable forcing and shear vorticity is being ushered in by this
low, while the broader trough at 500mb deepens and paints the jet
stream across the Carolinas. After a lull this morning, showers and
storms have picked up over the last couple of hours across the
Piedmont and upstate SC. Some of these showers are starting to make
their way into the SC Pee Dee region.

Isolated to scattered showers and storms expected through this
evening as the 850mb low continues to spin along with the
approaching front. The question all day has been about moisture.
Several members of the HREF show an inverted V sounding, and based
on current convective trends, the lower levels shouldn`t have much
of a problem to overcoming the lower layer of virga. The area
remains in a "Marginal risk" (threat level 1/5) for damaging winds
and large hail.

Hold skepticism that the severe chances will materialize.
Precipitable water values are currently hanging around 0.80-0.90",
but increased westerly flow aloft means that more moisture gets
taken out of the column. Less moisture means less buoyancy for
lifting parcels, which affects the hail threat. SBCAPE of 1000 J/kg
matches up very well with the daytime heating, and there is a good
sliver of it that falls within the -30C to -10C layer, which is what
you want for hail production. However, the majority of the
instability appears to be below this layer, so I have lower
confidence on severe hail. Parts of the SC Midlands recorded half-
inch hail recently, which seems about right. The damaging wind
threat is perhaps a bit more legitimate, given elevated DCAPE values
of 500-600 J/kg. This isn`t a screaming signature by any means, but
I think the wind threat is a bit more valid than the hail threat at
this time.

Shower and storm chances should taper off after 10 PM tonight as the
cold front moves through. Lows tonight in the mid-to-upper 40s.

Partly cloudy skies in store for Saturday, with cooler highs in the
mid 60s. May have a few sprinkles or an isolated shower at best in
the afternoon, particularly over southeast NC. Shortwaves traversing
along the main trough bring some elevated forcing from the
northwest, but it`ll have a hard time with limited moisture.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
High-amplitude mid/upper trough axis will move off the coast
Saturday night, with deep NW flow maintaining a dry column into
Sunday. A flat ridge will begin to build overhead Sunday night.
Saturday night will be the coolest night, with temps falling into
the lower 40s away from the coast. Temps rise Sunday into Sunday
night along with 850 mb heights. Highs Sunday will top out around
70, with lows Sunday night falling to the upper 40s inland, and 50-
55 across the coastal zones.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Flat ridging will build overhead Monday, followed by modest moisture
return Monday night as flow aloft turns WSW. On Tuesday, PW
continues to surge towards the 90th percentile for mid-April (based
on MHX sounding climatology), and GEFS probability for measurable
precip has reached 40-60%. The surface front will push offshore late
Tuesday, resulting in a midweek cooldown with highs Wednesday
ranging from the upper 60s north to around 70 south. Light winds and
clear skies Wednesday night should allow temps to fall into the
lower 40s away from the beaches, and even cooler in typical low
spots. Temperatures will moderate Thursday and Friday with another
cold front on the doorstep by the end of the week. Will maintain a
low PoP Friday to account for timing uncertainties as the front
approaches.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
Moderate to high confidence of VFR through most of the 18Z TAF
period. Isolated showers and storms may cause brief MVFR or IFR
restrictions from 21-02Z at KFLO/KLBT this evening, and then
23-02Z at KILM/KCRE/KMYR. Cold front pushes offshore tonight,
allowing for winds to go northwesterly. Some brief MVFR ceilings
may result with the frontal passage, but most should be in VFR
after 06-08Z tonight.

Extended Outlook...Mainly VFR late Saturday afternoon with a
few showers possible. High confidence in VFR following through
Wednesday.

&&

.MARINE...
Through Saturday...Westerly winds at 10-15 kts become northwesterly
after a cold front moves through late tonight. A few gusts up to 20
kts are likely. Seas remain locked in at 2-4 ft.

Saturday night through Wednesday...NNW winds are expected Saturday
night through Sunday morning, with speeds on the order of 10-15 kt
in a weakening pressure gradient. High pressure will slide off the
SE CONUS late Sunday and persist through Monday, bringing SW return
flow across the waters. The gradient will strengthen Monday and
Tuesday ahead of a cold front that should make it to the coast
Tuesday afternoon or evening. Wind speeds will surge to 15-20 kts,
with the possibility or reaching marginal Small Craft Advisory
thresholds ahead of fropa. Scattered to perhaps numerous showers are
expected along and ahead of the front as it moves off the coast late
Tuesday. NW winds will develop Tuesday night and continue through
Wednesday as high pressure builds across the southeastern
states.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.

&&

$$

SYNOPSIS...ILM
NEAR TERM...IGB
SHORT TERM...CRM
LONG TERM...CRM
AVIATION...IGB
MARINE...IGB/CRM