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-- Discussion containing changed information from previous version are highlighted. --
080
FXUS62 KILM 200147
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
947 PM EDT Tue Mar 19 2019

.SYNOPSIS...
Developing low pressure off the SC Coast tonight will move
northeast along the immediate NC Coast Wed into Thu. Patchy
light rain along the coast late tonight, will become more
widespread and push further inland during Wed. The rain will end
early Thu as the low lifts further north, away from the forecast
area. A cold frontal passage will occur late Fri followed by
seasonable high pressure for the weekend. A frontal boundary
accompanied with scattered showers will slowly drop south
across the region early next week.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
As of 830 PM Tuesday...Latest HRRR and HiResW indicate patchy
light rain late tonight and will back the rain potential to late
tonight in the 15 to 24 percent range with the hier side of
this range along the immediate NC coast and adjacent waters. The
inland SC zones should remain mostly dry. Protected areas from
north-northeast winds west of the I-95 corridor could see
patchy frost before more opaque ci moves in as well as low
level stratocu from the east. Sfc dewpts will be in the upper
20s to low 30s and do expect up to 5 degree sfc dewpoint
depressions. Winds may briefly go calm or decouple at the far NW
portions of the FA but overall do not expect a widespread
frost with min temps dropping to 36 to 39 degrees. This may
require a SPS.

Previous......................................................
As of 300 PM Tuesday...Tricky forecast on tap for the near term
period. First off, with temps mainly just getting down into the
upr 30s tonight (mid 30s though in coldest spots), not
expecting much in the way of frost with ~5 kt wind and dewpoints
down in the upr 20s. Exception may be over far western areas
where patchy frost is possible. Surface high pressure north of
the area this aftn slides offshore tonight. Meanwhile, coastal
low pressure gradually develops just offshore through Wednesday
as a mid-level shortwave trough approaches from the west. Result
will be increasing chances of rain from east to west through
the day Wednesday, continuing into Wednesday night, in response
to increasing low-level convergence and isentropic upglide. PoPs
increased to 60-70% for eastern areas where the rain may be
moderate to possibly heavy at times. As for temps, expect only
highs in the 50s Wednesday due to NE flow and a cloudy sky. Lows
temps Wednesday night mainly 40-45. &&

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...Surface low will lift off to the
north as potent shortwave crosses the Carolinas on Thursday. Any
lingering pcp from sfc low will move out of the area Thursday
morning. Dry air will wrap around the back end with some
clearing through the day, but mid to upper shortwave will ride
through later in the day with mainly clouds, but may see some
light pcp mainly to the north of local area over NC. Deep NW
flow will develop through Thurs night on back end of shortwave
moving out of area. This will give a little punch of CAA.
Overall, expect some clouds mixing with sun and low end pcp chc
on Thurs, but weather improving through Thurs night. Temps
should be near seasonable through the period with overnight lows
in the 40s and

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 300 PM Tuesday...High pressure will build in slowly from
the west and will migrate eastward through the weekend at the
same time as mid to upper ridge builds over the area. Overall,
expect a dry weekend with plenty of sunshine and warming temps.
The dry air mass in place will allow for some large diurnal
temp swings with afternoon highs just above normal and overnight
lows just below.

The center of the high will shift off shore Sunday night into
Monday. This will produce a southerly return flow which will
help to increase the temps and moisture, leading to some clouds
mixing with the sunshine on Monday, but temps warming into the
70s. By Mon night into Tues, mid to upper trough will dig down
over the Southeast. This will help to deepen sfc low as it
tracks east toward the coast while at the same time, a cold
front will drop down from the north. This will help to spread
clouds and pcp into the Carolinas Mon night into midweek. Cooler
air behind the front will drop temps quite a bit for Tues.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As of 00Z...Low pressure developing off the SE US coast will move
northward overnight. This has already started to bring in a mid-
level deck along the coast and this will continue overnight. Expect
MVFR conditions to develop on Wednesday morning. MVFR will be more
likely along the NC coast with SC terminals approaching MVFR later
in the morning. As of right now, most models have the developing low
pressure system remaining well offshore which will bring light rain
to ILM, with only VCSH throughout the day at coastal SC terminals. A
feed of low-level marine moisture could lead to the development of
IFR conditions along the coast with low stratus the primary threat,
late Wednesday afternoon; MVFR elsewhere. Showers ending after the
end of the forecast period. Northeast winds 5-10 knots increasing
throughout the forecast period.

Extended Outlook...Likely MVFR late Wednesday through Thursday with
storm system. VFR returns Friday into weekend.

&&

.MARINE...
As of 900 PM Tuesday...SCA conditions to continue across all
waters. Models are in decent agreement in developing a kink in
the sfc pressure gradient where the sfc low will develop on it.
This kink will extend from 41013 northwest to the Cape Fear
region overnight into Wed. Looking at winds becoming ENE to E
north of the kink and NNW-NNE south of this kink. Wind speeds
will increase to a solid 20 to 30 kt in the vicinity of this
kink with few to occasional gusts to Gale force. Significant
seas will further build from Cape Fear northward with double
digits possible...and hold steady south of the Cape as the fetch
decreases-some.

Previous..........................................................
As of 3 PM Tuesday...Small Craft Advisory continues over all
waters for a prolonged period of 15-25 kt NE winds with gusts up
to 30 kt. This as strong high pressure anchors off to the NE
and surface low pressure develops just offshore late Wednesday.
Winds may diminish as the center of low pressure moves directly
over the local waters Wednesday night, but continued high seas
may warrant an extension to the current Small Craft Advisory end
time (midnight Wednesday night).

Offshore flow will develop as high pressure begins to
build in behind departing low on Thursday. The diminishing off
shore flow will allow seas to subside from advisory levels Thurs
morning down to 3 to 5 ft by end of the day. Gradient will
remain a bit tight, though, as high pressure builds down and
low strengthens off the coast of New England into Fri. Therefore
winds may increase again Thurs night into early Fri, with seas
slower to drop, especially in the outer waters Fri.

By the weekend, winds will lighten as high pressure migrates
slowly eastward reaching overhead by Sunday. This will produce
improving marine conditions over the weekend with seas 2 to 4 ft
on Sat and down less than 2 ft on Sunday.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...None.
NC...Coastal Flood Advisory until 11 PM EDT this evening for NCZ107.
MARINE...Small Craft Advisory until midnight EDT Wednesday night for
     AMZ254-256.
     Small Craft Advisory until 10 PM EDT this evening for AMZ250-
     252.
     Gale Warning until 3 PM EDT Wednesday for AMZ250-252.
-- End Changed Discussion --

&&

$$
SYNOPSIS...
NEAR TERM...DCH/MAS
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...21
MARINE...