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000
FXUS62 KILM 240011
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
811 PM EDT Fri Jun 23 2017

.SYNOPSIS...
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Deep moisture will become increasingly squeezed by an approaching
cold front through Sunday morning. Some drier air should move
in later Sunday. More seasonable weather will return next week
with isolated mainly afternoon thunderstorms.
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&&

.NEAR TERM /THROUGH SATURDAY/...
As of 300 PM Friday...The KLTX 88D continues to be relatively echo
free across the ILM CWA. The relatively pinned sea breeze is
identifiable to a degree via the KLTX 88D. From hence on out thru
sunset, would not be surprised for isolated convection to break out
especially across the ILM SC CWA where the NVA aloft is not as
strong or prevalent like across the ILM NC CWA. Will only carry
isolated to widely scattered 15-25 POPs thru sunset followed by no
POPs for the night-time period.

Relatively oppressive, heat-wise, with sfc dewpoints in the mid and
upper 70s and temps around 90 this aftn and evening. Only saving
grace, is that the sfc winds will stay active this aftn thru
tonight, and likely continue thruout the day on Saturday. The sfc pg
will remain tightened thruout this period and will only show some
signs of relaxing well inland during late Sat due to the approaching
frontal boundary. With some decent forcing now avbl, will ramp POPS
up big-time during Sat aftn which will mesh nicely with the even
higher POPs slated for Sat night. With PWS back well over 2 inches
by Sat aftn, heavy rainfall will be the primary tstorm parameter to
affect the ILM CWA. If enough precip loading occurs, then wet
microbursts may become an issue.

As for max/min temps, just stayed with the meshing of the various
Model MOS Guidance which gives widespread 70s for tonights lows and
lower 90s for Sat highs and only mid-upper 80s along the immediate
coast given local SSTS are in the 80-85 range now.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
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As of 300 PM Friday...Slow moving cold front will move into the
region as the period begins with showers and thunderstorms
likely ongoing. There will be an abundance of deep moisture for
much of the period. Precipitable water values rise to almost
2.25 inches Sat night into Sun. Surface based instability will
be lacking Sat night but convergence along the weak surface
boundary as well as the presence of outflows in a moist,
conditionally unstable environment should maintain at least some
nocturnal convection. In addition there will be a little bit of
shortwave energy approaching from the southwest which should
lead to an increase in PVA after midnight. Storm coverage will
be highest along the coast but everywhere will have at least a
chance of showers and thunderstorms overnight.

Front and deep moisture remain in the area Sun, although the 5h
trough and drier air to the northwest start moving into northwestern
portions of the forecast area later in the day. This will likely
curtail convection in these areas but closer to the coast coverage
will be higher. There will be another in a stream of shortwaves
within the vorticity channel that spreads some PVA into the area on
Sun. Combined with surface heating this should light off another
round of convection. Storm motion will be around 15 kt which should
prevent any 1 storm from posing a flooding risk however, training
storms could pose a problem. Storms that develop will be very
efficient at producing rainfall having warm cloud layers on the
order of 13k-14k ft deep. While severe weather is unlikely given
vertical profiles/limited shear a wet microburst from a storm cannot
be ruled out. Still the main concern Sun will be flooding and not
strong to severe storms.

Dry air spreads in from the northwest late Sun and Sun night with
most if not all convection shifting off the coast by midnight. Push
of dry air is significant with pwats forecast to drop over an inch
from 18Z Sun to 06Z Sun night. Some convection just off the coast
cannot be ruled out late Sun night but wind direction/storm motion
would tend to push any activity off the coast and thus pop after
midnight is unlikely. Temperatures Sat night will run well above
climo while temps Sun and Sun night will be near climo.
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&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 300 PM Friday...Mid level troughiness Monday sharpens through
Tuesday or Wednesday. Initially this will be a dry westerly flow
Monday but a slightly more moisture-laden WSW flow Tuesday. Daytime
temperatures will be held a bit below climatology through this time
frame. The trough axis appears to swing through on Wednesday
bringing a more decided drying. The rest of the period will be
characterized by a building upper ridge over the Southeast and
Bahamas. This will mark a transition back towards seasonable
temperatures and isolated convection mainly during the diurnal
maximum.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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As of 00Z...A few spot showers from earlier in the day have
dissipated. Convective cloud debris continues to work across
the area from the SW while more clouds well upstream continue to
work in our direction. We expect VFR through the first part of
the overnight. A stiff nocturnal jet will keep things well mixed
overnight and we expect gusts around 20 kt to continue for the
coastal terminals with winds backing down to 10 to 15 kt at KFLO
and KFLO this eve. The direction will be SW. Expect winds of 15
to 25 kt on Sat, again from the SW.

Model profiles continue to show an inversion 1-2 kft above the
surface developing overnight and given what transpired last
night, went ahead to include stratus near 1kft with ceilings at
all the terminals in the 08-09z through about 13z.

Sat is expected to be an unsettled day with numerous thunderstorms
developing during the afternoon and then persisting into the
nighttime hours. These thunderstorms will have the potential for
significant flight restrictions. At this time included a
prevailing group for thunderstorms after 20-22z at all the
terminals.

Extended Outlook...MVFR/IFR conditions are possible in
thunderstorms Saturday night and into Sunday. Thunderstorms are
expected to be most numerous Saturday evening and overnight.
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&&

.MARINE...
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NEAR TERM /THROUGH Saturday/...
As of 300 PM Friday...Marine conditions will continue to erode
thruout this period with SCEC conditions developing this evening
and further eroding to SCA conditions after midnight tonight.
This a result of the sfc pg, that continues to tighten as a sfc
cold front drops southeast into the western Carolinas late
tonight. At the same time, the Cindy remnants, will move along
this cold front, reaching the DELMARVA coast Sat morning. Wind
directions will run SSW-SW at 10 to 20 kt speeds thru this
evening and veer slightly to SW-WSW at 15 to 25 kt speeds toward
daybreak Sat and continue thru daylight Sat and into Sat
Evening. Wind driven waves at 3 to 5 second periods will
dominate the significant seas and should peak in the 3 to 6 foot
range with a few 7 footers off Cape Fear and Romain
respectively. Moderate to strong longshore currents will become
apparent, especially south of Cape Fear to Murrells Inlet.

SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM Friday...Will continue to carry small craft
advisory headline Sat night but hazard will be marginal at best.
Front moving into the area combined with Bermuda High will
tighten the gradient and speeds will increase to a solid 20 kt.
Sustained 25 kt may be hard to come by and highest seas may end
up closer to 5 ft than 6 ft but given at least some uncertainty
with respect to the strength of the surface features will
maintain the headline unchanged. Bermuda High remains in control
Sun with southwest winds continuing, though in a weaker state
as the front slowly moves closer and the high retreats east.
Winds and seas will gradually decrease Sun into Sun night with
flow becoming offshore late in the period as the surface
boundary slips east of the waters.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 300 PM Friday...Not a typical summertime pattern in place
for most of the period. A sharpening mid level trough will be
in place. A series of weak surface boundaries may come through
but with only very minor fluctuations of wind direction, though
a northerly component will dominate. Wind speeds never really
look to exceed 10kt by much though a few higher gusts will be
possible. Seas will average 2 to occasionally 3 ft with near
shore wave shadowing much more pronounced than usual this time
of year where SW winds much more common.
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&&

.ILM WATCHES/WARNINGS/ADVISORIES...
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SC...Beach Hazards Statement through Saturday evening for SCZ054-
     056.
NC...Beach Hazards Statement through Saturday evening for NCZ106-
     108.
     Coastal Flood Advisory until 11 PM EDT this evening for NCZ107.
MARINE...Small Craft Advisory from midnight tonight to 6 AM EDT Sunday
     for AMZ250-252-254-256.
-- End Changed Discussion --

&&

$$

NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...III
AVIATION...RJD