-- Discussion containing changed information from previous version are highlighted. --
765
FXUS62 KILM 170539
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
139 AM EDT Fri May 17 2024

.SYNOPSIS...
Quiet overnight as high pressure drifts offshore. Rain
chances will increase late Fri thru the upcoming weekend as
a new storm system advances eastward across the Southeast. As
the low exits the Carolina coast Sun, a cold front will push
offshore bringing below normal temperatures Mon and Tue.

&&

.UPDATE...
-- Changed Discussion --
Some tweaking to hrly temps/dewpts this evening and overnight
applied...and a degree tweak upwards for tonights min temps
applied. This aided by the latest obs/trends meshing to the
ongoing fcst. Did add some additional patchy fog but kept
low stratus at bay. Due to a relaxed sfc pg, winds should go
calm for half the night at any given location and enough sfc
based moisture for rad fog to occur. Question is will the fog
become areas to widespread in coverage and will it reach dense
thresholds. Confidence too low to go any further with the fog
potential other than at a point fcst site, ie. at an airport
terminal forecast (TAF).

Marine, sfc pressure pattern and relaxed gradient will continue
with a SW-W wind at 5 to 10 kt. Seas generally 2 to occasionally
3 ft, primarily from a 7 second period SE-SSE wave.|
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&&

.NEAR TERM /THROUGH TODAY/...
Pretty quiet for most of the period with WV imagery showing
considerable dry air filtering in behind yesterday`s severe
weather- causing upper lows. Surface dewpoints haven`t lowered
much so we could still see some fog develop towards daybreak but
not with the vigor as this morning. The Pee Dee and possibly
Grand Strand have the best chance for some lowered visibility.
A light return flow will moisten the atmosphere tomorrow
bringing increasing cloud cover all day. A midday shortwave will
at least have opportunity to touch off isolated convection that
may or not become deep based upon how weak the progged
instability stays. Weak WAA will bring highs in the mid to upper
80s Friday after seasonable temperatures tonight.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
Warm front will lift north of the area Friday night. Poor
saturation ahead of the warm front will keep showers isolated
Friday night into early Saturday. Southwesterly flow will bring
Gulf moisture into the region by early Saturday and shower
chances will increase with the deepening saturation. An
approaching shortwave will combine with isentropic lift and
marginal instability to create widespread showers and a few
thunderstorms. During the afternoon, an approaching cold front
will expand the coverage of showers and storms. Marginal
instability and weak shear could produce a damaging wind gust or
two in the stronger storms on Saturday afternoon. Around an
inch of rain is forecast with higher amounts likely where
convective training occurs. Flash flooding and heavy rain may
become the dominant threat.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
An upper low will maintain unsettled weather on Sunday. As a
developing surface low just offshore pushes a cold front
southward through the area. Mid level lapse rates and warm air
south of the front will likely lift along the front and create
another period of showers and thunderstorms. The severe threat
on Sunday is low, but a continued deluge of rain with previously
saturated soils will prolong the flooding rain threat.

Surface low continues to develop offshore on Monday. A thin
layer of saturation and cooler temperatures may promote a few
light showers, especially early Monday. High temperatures with
clouds and persistent northerly winds will be in the low to mid
70s.

A few lingering showers along the coast early Tuesday should be
overcome by dry air advection. It will be worth mentioning the
potential for lingering cloud cover as a subsidence inversion
aloft traps some low level moisture. Upper 70s are expected in
clouds and northerly flow. A few ambitious sites may see highs
at 80. A quick warmup is anticipated on Wednesday and Thursday
as low pressure exits the region and the next cold front
approaches from the west.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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Currently VFR across the area. There remains a chance for fog
before morning, mainly MVFR with patches of IFR/LIFR possible,
although saturated layer at surface is quite thin. Couple
things to keep an eye on: stretch of mid clouds moving down
from the south across NC and lingering WSW winds around 5 kts in
the area. If clouds and winds linger, chances of fog will
decrease quickly and TAF amendments will be necessary.

After daybreak, VFR to dominate rest of TAF period. Mid clouds
will be thickening during the day, around 10 kft, and lowering
this evening into tonight, though expect sub-VFR ceilings to
hold off until after 6z Saturday morning. A few storms are
possible this afternoon and evening associated with an upper
shortwave, but coverage not enough for TAF inclusion. Rain
chances increase tonight, with isolated thunder possible. Winds
remain relatively light out of the south today into tonight.

Extended Outlook...The next storm system and associated
periodic flight restrictions will affect the area late Fri night
thru the weekend and likely into Mon.
-- End Changed Discussion --

&&

.MARINE...
Through Friday... Wind will remain light and waves small. The
former will be caused by a weak pressure gradient, the latter by
the absence of swell leaving behind only the diminutive wind
wave. (backswell from the storm off NE coast will not come this
far west).

Friday Night through Tuesday Night... Low pressure will develop
late Friday night into Saturday as winds turn southerly and
increase. Showers and storms develop on Saturday and will likely
continue through the weekend. A cold front will drop southward
on Sunday as low pressure develops off the coast. Winds turn
northerly late Sunday night behind the low and increase to 15-20
knots with gusts to 25 knots. SCA conditions are possible as
this low develops off the coast through Tuesday. Showers and
storm chances continue until the low finally starts to move
offshore into Wednesday.

&&

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

&&

$$

SYNOPSIS...ILM
UPDATE...DCH
NEAR TERM...MBB
SHORT TERM...21
LONG TERM...21
AVIATION...VAO
MARINE...MBB/21