Myrtle Beach, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

408
FXUS62 KILM 211137
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
637 AM EST Thu Nov 21 2024

.SYNOPSIS...
Colder end to the week expected behind a strong cold front,
possibly leading to frost or even freezing conditions inland each
night. High pressure will move off the coast early next week
with warmer temperatures expected. A weaker cold front could
move through toward mid week.

&&

.UPDATE...
Only notable changes are to better align temps and dewpoints
with their current observations as some locations are reporting
considerably lower values than expected.

&&

.NEAR TERM /THROUGH TONIGHT/...
A strong cold front has moved offshore early this morning with gusty
NW winds and dew points mainly in the 30s across the region. Expect
these winds to slow down late tonight into early this morning as the
pressure gradient relaxes. After sunrise, the growing boundary layer
(expected to reach up to around 850mb at peak heating) will tap into
faster winds aloft and allow for gusty west winds up to around 20-25
kts to develop around midday and continue through the afternoon.
High temps will struggle to reach 60F amidst persistent cold
advection and a robust subsidence inversion. With the loss of
heating, gusty winds driven by vertical mixing will subside late
this afternoon into this evening.

However, another surge of WNW flow with even drier dew points behind
a secondary cold front is expected to push in between 23-04Z this
evening, which should bring some temporary gusty winds back into the
mix, although speeds will be less than during the day. A weakening
pressure gradient will allow for winds to decrease during the latter
half of the night, and with clear skies in place, temperatures have
the potential to drop to around the freezing mark, particularly
across the northern tier of counties in our CWA. Therefore, a Freeze
Watch has been issued to account for this possibility. Dew points
depressions should be large enough to preclude widespread frost, but
preferred areas near a water source or irrigated land may be able to
yield frost due to locally higher dew points.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Highlights:
*Dry w/ below normal temperatures
*Frost/freeze conditions possible inland Fri/Sat nights

Confidence:
*Moderate to High

Details:

General troughing will prevail through Friday night with high
pressure returning thereafter. Temperatures will stay below normal
through the period with highs only in the lower to mid 50s Friday
and lower 60s Saturday. Overnight lows will be in the 30s away from
the coast each night, possibly near freezing in spots. Such
temperatures could support frost as well, although there is some
uncertainty regarding temps, humidities and winds. Also, should note
that the issuance of Freeze Watches/Warnings and Frost Advisories
will be predicated on whether freezing temperatures occur tonight
which would end the growing season in these areas.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Highlights:
*Warming trend early in the week w/ above normal temps starting Mon
*Cold front could bring cooler temps and a few showers toward mid
week

Confidence:
*Moderate

Details:

High pressure will be shifting offshore bringing moderating temps
and moisture levels. A cold front looks to approach toward mid week,
possibly moving into and/or through the area as early as Tuesday.
Moisture and forcing appear weak so not expecting much rainfall with
this feature, although some showers will be possible.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR. After sunrise, a growing boundary layer will promote a
return of breezy west winds at all terminals with gustiness
returning around midday. Wind gusts are expected to reach
around 20-25 kts during the afternoon as the boundary layer
reaches up to around 850mb. Winds will relax somewhat after
sunset, but remain steady westerly. A brief period of gusty
winds may occur after 00Z as a secondary cold front pushes
through with a surge of WNW winds arriving behind it. Winds
will gradually slacken overnight and may even go calm towards
daybreak.


Extended Outlook...Expect VFR through the period as high pressure
maintains control. Gusty winds will be the only concern on Friday
and Saturday afternoons.

&&

.MARINE...
Through Tonight... Breezy NW winds will gradually subside this
morning and back to westerly as the pressure gradient weakens and a
weak surface ridge passes through. Winds and gustiness increase
again this afternoon and veer to WNW this evening as another surge
of cold advection pushes in. Seas will be dominated by wind waves
with 2-4 ft waves temporarily subsiding this morning and early
afternoon before rebounding to 3-5 ft this evening as a result of
the increase in winds later in the day. Some 6 ft waves may be found
in outer portions of the coastal waters near 20nmi offshore of Cape
Fear during the first half of the night before gradually subsiding
thereafter.

Friday through Monday...A tight pressure gradient and cold advection
will keep winds/seas elevated through Friday night and a Small Craft
Advisory remains in effect through this period. High pressure will
then build into the area this weekend leading to a relaxation of the
pressure gradient and thus improving marine conditions.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...Freeze Watch from late tonight through Friday morning for
     NCZ087-096-105.
SC...Freeze Watch from late tonight through Friday morning for
     SCZ017-023-024.
MARINE...Small Craft Advisory until 7 AM EST Saturday for AMZ250-252-
     254-256.

&&

$$

SYNOPSIS...ILM
UPDATE...ABW
NEAR TERM...ABW
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...ABW
MARINE...RJB/ABW