Area Forecast Discussion
Issued by NWS Wilmington, NC

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FXUS62 KILM 251658

Area Forecast Discussion
National Weather Service Wilmington NC
1258 PM EDT Tue Apr 25 2017

A slow moving storm system nearly overhead this morning, will
lift northeast away from the area this afternoon through mid
week. Look for slowly improving conditions, with a warming and
drying trend. A weak cold front will dissipate as it moves
across the area Thursday night, followed by high pressure aloft
and early summer-like conditions Friday into the weekend. A few
locations away from the coast, may break the 90 degree mark this


As of 1136 AM Tuesday...Wrap around moisture associated with a
slowly departing upper low is beginning to make inroads and
bringing an uptick in mid-level moisture into the area. Local
forecast soundings show a bit of convective inhibition between
4-9 KFT that will gradually be overcome as surface heating
begins to increase and mid-level moisture bleeds in. As a result
we may see an increase in convection in the middle to late
afternoon and showers already are popping across the Bladen
Lakes area situated along the eastern edge of the moisture plume
diving to the SSE presently. As a result no significant changes
are being made to the afternoon forecast except to fine tune
pop distribution and tweak T/TD. A slight chance of a TSTM
remains intact and there remains a non-zero chance of small hail
with any strong shower or storm given the cold temperatures
aloft, as the -20C isotherm is not much higher than 20 KFT. Low
level wind speeds do not support much of a wind threat with
convection but gusty winds of 30-40 mph is not out of the
question with any TSTM that does develop due to downdraft CAPE


As of 330 AM Tuesday...At the start of this period, the nemesis
closed low aloft, off the DELMARVA Coast, will continue to fill
in as it tracks to the northeast, further away from the
forecast area. It`s corresponding, captured sfc low, will also
be weakening during this time-frame. Overall, in their wake,
the ILM CWA will commence an extended "drying out out" period.
Weak s/w ridging aloft will affect the FA thru Thu night. It`s
upper ridge axis will lie overhead Thu morning, moving off the
Carolina coasts by Fri daybreak. A rather expansive upper trof
will have taken shape across the central U.S. by Fri morning.

At the sfc, weak cyclonic NW flow will dominate the FA early
Wed until the upper/sfc lows move far enough away. By late Wed
thru daybreak Fri, sfc ridging from Bermuda High pressure
centered well east of Florida, will extend WNW and onshore
in the vicinity or south of Cape Romain, SC. Enough moisture in
the low levels will be avbl for diurnally driven cu fields each
day. Enough subsidence aloft will prevent the cu from growing
too much in the vertical, resulting in no POPs being advertised
Wed thru sunset Thu. A fading cold front will push across the FA
from the west late Thu night. The front will be displaced a good
distance from it`s parent low as it traverses the ILM CWA. Other
than frontal dynamics, not much forcing is left for pcpn
development. As a result, will include low chance pops for
showers and possibly an isolated tstorm Thu night if enough
instability becomes avbl. A low level SW jet will develop during
Thu night into early Fri. This will keep winds active enough at
the sfc to prevent widespread fog but also keep min temps on the
high side.

Summer time temperatures will be back across the FA with
widespread max temps in the low to mid 80s Wed and mid to upper
80s Thu. Min temps will follow the general trend and run in the
low 60s Wed night and the mid to upper 60s Thu night. This a
consensus amongst the avbl model mos guidance. This fcst has
temps that will run 10 to 15 degrees above normal by the end of
this period. Normal lows/highs are in the low to mid 50s and the
upper 70s respectively.


As of 3 PM Monday...Medium range guidance is fairly consistent
with regards to the extended forecast. Longwave troughing will
be in place out west with a cutoff low eventually developing
with a southwest flow and strong ridging developing just off the
southeast coast. At the surface it will be primarily high
pressure anchored offshore. A weak front will fade away as it
moves across the FA early Fri leaving a continued dry forecast.
Temperature trends remain mostly intact well above normal
throughout the period but moreso first half as heights fall
slightly late in the period.


As of 17Z...MVFR cigs this afternoon further improving to
MVFR/VFR conditions late this aftn thru tonight.

As the upper low lifts NE, away from the area this afternoon
and night, improving conditions across weather parameters will
occur. Will still have to contend with light to moderate showers
over SE NC until 00z-01z. Patchy fog late tonight mainly along
and west of I-95.

Wind directions will become w to nw throughout. Wind speeds
will run 10-15 kt this afternoon and drop back to 5 kt or less
during this evening and overnight.

Extended outlook...Possible MVFR/IFR from fog early Wed
morning. VFR expected from Wednesday through Saturday.


As of 822 AM Tuesday...The SCA for SC has expired as seas have
fallen below 6 feet for the majority of the 0-20 NM waters
there, no other changes.

As of 330 AM Tuesday...Low pressure just off the Grand Strand
will spin slowly off to the NE today. As this surface feature
pulls away, winds will become predominantly S/SW and increase
back towards 15-20 kts before slowly veering to the West, and
then NW tonight, while easing to around 10 kts. Seas remain high
this morning thanks to a variety of wave groups, and the SCA
has been extended for the NC waters through late this aftn,
while expiring in the next few hours across the SC waters. Seas
recently at 41013 were still near 9 ft, and 7 ft at 41004.
Expect these to gradually ease through today, becoming a more
uniform 3-5 ft this evening, and 2-4 ft tonight, as both the SE
swell and SW wind wave begin to decay in amplitude.

As of 330 AM Tuesday...Improving seas and winds will continue
from where the near term left off as the last affects from the
departing upper and sfc lows occur early Wed with diminishing NW
flow and a transition to light SSE to SSW flow by late Wed and
continuing thru Thu night. This a result of sfc ridging, from
Bermuda high pressure located well offshore and east of Florida,
extending WNW and onshore in the vicinity of Cape Romain by and
thru Thu. Wind speeds around 10 kt Wed, with 10 to 15 kt near
shore Wed aftn/evening due to a weak sea breeze. Wind speeds Thu
will run 10 to 15 kt, except 10-20 kt near shore Thu
aftn/evening due to a moderate sea breeze. The ESE ground swell
at 8 to 9 second periods, will dominate the seas spectrum Wed
and for much of Thu. A low level SW jet Thu night will keep
winds active thru the night resulting in 3 to 5 second period
wind waves becoming more dominate.

As of 3 PM Monday...Essentially a summertime pattern for the
coastal waters as ridging from Bermuda High pressure affects
the area waters thruout this time frame. South to southeast
winds of 10-15 knots will prevail Friday through Saturday.
Significant seas will be 2-4 feet.


MARINE...Small Craft Advisory until 5 PM EDT this afternoon for AMZ250-



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