106
FXUS62 KILM 160726
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
326 AM EDT Thu May 16 2024

.SYNOPSIS...
High pressure should bring dry weather today with pleasant
temperatures. Rain chances will increase again this weekend as a
new storm system advances eastward across the Southeast. As the
low exits the Carolina coast Sunday, a cold front will push
offshore bringing below normal temperatures Monday and Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Widespread low stratus deck currently across most of southeast NC is
expected to extend south into parts of the Pee Dee region over the
next few hours. This low cloud deck may be stubborn during the
morning and linger for a few hours past sunrise as winds remain
light and minimal drying present below 700mb and thus how
expansive/thick the stratus is will dictate how long it will take
for the May sunshine to mix it out. After the low clouds dissipate,
some afternoon diurnal cumulus will develop with high temps around
80-83F. There is a chance for an isolated storm along pinned sea
breeze this afternoon, with light NW winds inland aiding
convergence, and have included 15-20% pops across parts of Horry,
Brunswick, and New Hanover counties. Ridge moves overhead tonight
with clear skies and light winds allowing temps to drop to low-mid
60s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A shortwave ridge will move eastward across the coastal Carolinas
Friday morning. Surface high pressure centered just downstream
of this ridge will accompany it offshore, allowing southerly
flow to develop during the day. The ridge`s capping subsidence
inversion will decay as mid level temps cool with the approach
of an upper disturbance from the southwest. All this should
allow scattered showers and thunderstorms to develop across
South Carolina during the afternoon, pushing east to the coast
Friday night.

For the past several days models have had little, if any,
consistency with their depictions of the upper level pattern and
sensible weather this weekend. Over the past 24 hours broad
consensus has begun to emerge and confidence is finally beginning
to increase. A moderate-strength shortwave over the southern
Mississippi Valley Saturday morning should slowly shift east
toward the southern Appalachians by late Saturday night. Deep
southerly flow from the Gulf will lead to both isentropic lift
plus convective instability across the Carolinas, helping to
develop widespread showers and embedded thunderstorms. Surface
low pressure will develop early Saturday across the Mid South
and should discontinuously move eastward, modulated by
convective activity, until it reaches the Carolina coast after
midnight. Over an inch of rain is forecast with higher amounts
likely where convective training occurs.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Model consensus has begun to increase for early next week,
although it`s in a different way than what was expected just 24
hours ago. An elongated area of surface low pressure should
extend across the eastern Carolinas and offshore Sunday. As an
upper level disturbance across the southern Appalachians moves
eastward, it should help consolidate the low fully offshore,
dragging a significant cold front southward across the area.
Lift across this initially shallow front should lead to another
round of significant rain and thunderstorms Sunday afternoon and
evening, finally tapering off as the upper disturbance moves
offshore. Although this is beyond our official rainfall amount
forecasts, indications are a widespread half inch could occur
with embedded higher amounts.

Upper level ridging developing across the Great Lakes and New
England will build north of our offshore disturbance Monday
into Tuesday, leading to the disturbance either slowing
appreciably or cutting off entirely. This may occur close enough
to the Carolinas to provide one or two days of unseasonably
cool northerly winds with coastal clouds and showers. I`ve
trimmed back forecast highs significantly both days, although
not quite as steeply as the 00z model consensus would indicate
to maintain better continuity with our neighboring NWS office
forecasts. Highs on Monday may have trouble rising much beyond
the mid 70s.

By Wednesday a shortwave moving eastward across Canada should
erode the upper ridge to our north, allowing the captured
shortwave off the Carolina coast to begin to progress eastward
again. Assuming this occurs, we`ll finally break back out into
sun and seasonably warm temperatures.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LIFR stratus deck around 300-400 ft has developed across most of
southeast NC, including KILM and KLBT. With abundant low level
moisture available, in part due to Wednesday`s storms, look for
this stratus deck to continue expanding southward. Have low
clouds moving into KFLo around 8-9z. Confidence is less along
coastal NE SC (i.e., CRE and MYR) where this is a lower chance
of the stratus deck making it that far. Have still included
TEMPO groups for both, mainly for lower vsbys.

With light winds and minimal low level drying, morning stratus
may be a bit stubborn after daybreak and take a few hours to
burn off. After the stratus dissipates (perhaps 14-16z), look
for some diurnal cumulus to develop with an isolated storm
possible along pinned sea breeze in the afternoon. Winds remain
fairly light throughout TAF period.

Extended Outlook...VFR conditions to dominate Thursday night
through Friday. The next system with potential periodic flight
restrictions will affect the area this weekend into Monday.

&&

.MARINE...
Through Tonight...Conditions will continue to improve across the
local coastal waters with earlier storms far offshore and surface
ridging building in from the west during the day. Seas 3-4 ft at
daybreak this morning will lower to 2-3 ft this afternoon and around
2 ft tonight, combination of quickly weakening S swell and a 1 ft E
swell. Light offshore winds early today will turn southeasterly with
sea breeze this afternoon.

Friday through Monday...Light and variable winds Friday morning
beneath high pressure will become southerly by afternoon as the
high shifts offshore. Low pressure should gradually take shape
across the Mid South Friday night, expanding eastward on
Saturday.

For the past several days weather models displayed an unusually
large spread in possible outcomes for this weekend into early
next week. While we`re still far from certain, this morning`s
new model runs are converging on the idea that low pressure will
move eastward across the Carolinas on Saturday and Saturday
night developing widespread rain and thunderstorms. The low will
move offshore late Sunday, dragging a cold front southward
across the the area. A sizable pressure difference should
develop between the offshore low and the colder air inland and
Small Craft Advisory conditions in winds and seas may develop
Monday. This general scenario is now shown by the 00z runs of
the GFS, Canadian, and ECMWF models.

&&

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

&&

$$

SYNOPSIS...TRA
NEAR TERM...VAO
SHORT TERM...TRA
LONG TERM...TRA
AVIATION...VAO
MARINE...TRA/VAO