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000
FXUS62 KILM 111331
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
931 AM EDT Fri Aug 11 2017

.SYNOPSIS...
An offshore front will meander landward today into the weekend,
while a cold front approaches early next week and stalls. These
features will maintain rain chances through much of the period.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 930 AM Friday...Analysis of morning sounding data shows a
very juicy and moderately unstable atmosphere although with a
lack of any significant triggers other than the sea breeze
front. High-Res guidance concentrates convection today along
this boundry and then moves it inland into the afternoon. Have
tweaked pop grids to reflect this evolution. Main threat today
appears to be from possible localized flooding from slow- moving
and training storms. Previous discussion follows:

Remains of the frontal boundary moving inland, traced out by
some isolated showers now roughly bisecting the area west to
east. As this boundary becomes more and more diffuse to our west
today there may be little organized forcing for showers and
thunderstorms, though smaller scale boundaries may be aplenty.
One thing that illustrates this is the precipitation
distribution between the GFS and WRF. The former shifts the main
precip axis inland while the latter favors the coastal areas
for most of the day. More factors seem to favor the WRF solution
than the GFS including forecast continuity. Despite fairly
widespread cloud cover afternoon temperatures should warm up to
near seasonable norms. Some overnight convergence tonight will
maintain rain chances mainly along the coast ahead of a very
weak low developing over Savannah. In fact, those rain chances
may end up being higher than those seen all day.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 333 AM Friday...The damp regime continues this period.
This is supported by precipitable water values in excess of 2
inches, August heating, and an ample dose of low level
convergence over the weekend. While it seems true rain-free
stretches will also prevail, the opportunity exists for areas to
capture several inches of rainfall this period. The coast and
coastal interior may be subject to oceanic convective downpours
in the morning hours, while the synoptic flow favors boundary
spawned showers and storms well inland in the afternoon to early
evening. As has been the case for August so far, this drenched
pattern has kept daytime and even average temperatures well
below normal for August and this looks to continue. The slightly
above normal minimums are being over-shadowed by the larger
departures in cooler maximums and across the forecast area, we
are nearly 3 degrees below normal for typical August warmth
overall so far.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 3 PM Thursday...An abundance of moisture will prevail
across a swath over the Carolinas with very high precipitable
water values expected by Tuesday. The Carolinas will be between
a subtropical ridge far off the mid-Atlantic coast and a
developing trough through the Upper Midwest and Midwest through
Monday and into the Ohio Valley during Tuesday. The trough will
further amplify across the Eastern United States during
Wednesday enabling a cold front to push south across the area
with drying and cooler temperatures around the middle and latter
portions of the upcoming week. In the meantime expect good
chance to likely POPs Sun-Tue time frame. MEX highs may be a
category on the high side depending on the amount of cloud cover
that occurs. MEX lows appear reasonable with lows in the mid-
upper 70s at the coast and mid 70s inland, then possibly upper
60s toward the latter half of the week.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
As of 12Z...Showers will gradually overspread coastal areas
today as front moves inland and a coastal trough develops.
Inland terminals will deal with some IFR or even brief LIFR cigs
and vsbys. Most areas til 15z will be IFR/MVFR while early fog
and stratus continue to affect terminals on and off through the
afternoon, possibly tapering some this evening.

Extended Outlook...Periods of MVFR/IFR ceilings and visibility
are possible each day due to scattered showers and
thunderstorms.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 930 AM Friday...Latest guidance shows light southerly
winds with 2 to 3 ft seas over the waters this morning. Forecast
good to go with no changes need to the near term. Previous
discussion follows:

Wind has turned back to southerly now that the front has moved
inland. As today wears on and the boundary dissipates so to will
the pressure trough associated with it. This should add a few
knots of wind to the forecast opening up the range to a fairly
seasonable 10-15. Seas will run 2 to 3 ft in the very near term
but then graduate to 3 ft across most of the area. Not much
change during the overnight save for possibly a few gusts to 20
knots due to a small uptick in the winds just off the surface.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 333 AM Friday...Bermuda high pressure building landward
Saturday will boost SW winds into a 15-20 KT range as the high
interacts with lower pressure inland. As low pressure weakens
Sunday, winds should fall about 5 KT compared to Saturday.
Scattered to numerous showers and storms will prevail this
period as weak boundaries waffle across the waters. Some storms
may be strong and a radar update is encouraged over the weekend
as winds and seas will be higher in and near TSTMS. Seas of 3-4
feet will be a mix of SSW waves around 2 feet every 5-6 seconds
and SE waves around 2 feet every 7-9 seconds. Moderate SW chop
can be expected Saturday as well. Any showers or storms this
weekend will move mainly toward the N and NE.

LONG TERM /MONDAY THROUGH TUESDAY/...
As of 3 PM Thursday...Weak troughing inland with high pressure
off the coast will support a south to southwest fetch Monday
through Tuesday. A front will drop south toward the waters,
possibly by late Tuesday night or Wednesday morning. The
aforementioned fetch will likely lead to dominant S-SW waves
along with weak ground swell from the E-SE.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...99
NEAR TERM...MBB
SHORT TERM...MJC
LONG TERM...SRP
AVIATION...MBB
MARINE...MJC/REK/MBB/SRP