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000
FXUS62 KILM 151436
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
1035 AM EDT Tue Aug 15 2017

.SYNOPSIS...
Summertime heat and humidity will build and should peak Wednesday
through Friday as showers and thunderstorms gradually become
fewer in number. Showers and thunderstorms will be on the
increase during the weekend as a cold front approaches from the
north. This front may actually push to our south early next week
as cooler high pressure builds from the north.

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 1030 AM Tuesday...Areas of stratus and strato-cumulus are
decreasing in coverage and becoming increasingly cumuliform with the
day`s heating. A few showers have already developed in the vicinity
of Cape Fear and expect widely scattered to scattered convection to
initiate along the sea breeze as the primary focus today in a high
precipitable water environment. Will need to re-asses with new model
data however could see a new round of convection tonight as an
impulse in the westerly flow moves primarily across NC. Otherwise
heat and humidity will become the main issue with heat indices of
100 to 104 this afternoon (along with a few pockets of 105
possible). Warm low temperatures expected again tonight with the
heat issues persisting into the short term period. Otherwise, Gert`s
swells are moving into the beaches. WaveWatch appears to be 1-2 ft
too high with this swell, however enough swell to support enhanced
rip current risks at all beaches (especially the E and SE facing
beaches).
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...The period will be dominated by high heat
and humidity. A Heat Advisory may be required both days for heat
index values near or in excess of 105 deg. High temps will be
mainly in the lower to mid 90s with near 90 at the beaches where
the seabreeze should have a difficult time pushing inland given
the deep WNW to NW flow just off the surface. Lows will be in
the muggy mid and upper 70s.

A very warm ridge of high pressure will be centered across FL
and portions of the Southeast states during this period.
Subsidence and warmer temps aloft should help to decrease, but
not eliminate the number of showers and thunderstorms. A weak
front should be all but washed out and the seabreeze looks like
it will be the primary impetus for convection, especially on
Wed when subsidence and warmer temps aloft will be building, but
not quite as strong as on Thu. The Piedmont Trough may also act
to focus showers and thunderstorms as it will be displaced
further east given the flow aloft.

A NW flow will become established across the area and this flow
is often tricky for the Carolinas and will continue to monitor
for any upstream impulses aloft which would warrant higher POPS.
However, at this time, will show higher POPs Wed than on Thu,
mainly scattered. Eve convection should tend to dissipate
quickly with loss of heating.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 PM Monday...Ridge building across the Southeast late
in the week will bring increasing heat and humidity before a
cold front drops into the region for the wknd. Highs Friday
will likely climb well into the 90s away from the beaches as
850mb temps climb above 20C, and this will combine with
continued high dewpoints and humidity to produce heat index
values above 100 degrees. This environment is supportive of
typical aftn thunderstorms, but coverage is not forecast to be
too widespread as the ridge aloft helps to minimize total
convective development. Still, will carry CHC POP, focused
along the typical boundaries, and any storm could produce
torrential rainfall.

The cold front drops into the area Saturday as a 500mb shortwave
digs into the OH VLY and then shifts east through Sunday. This will
push the front through the area before stalling and beginning to
dissipate on Monday thanks to increasing mid-level heights again
behind the departing shortwave. Showers and thunderstorms will
become widespread Saturday and possibly again on Sunday before W/NW
flow behind the aforementioned shortwave begins to dry the column.
Temperatures and humidity will remain elevated although cooler than
late week.

First glance at the all-important Monday forecast is looking
promising right now for the solar eclipse watchers out there. If the
front can sag far enough south as currently shown by long-range
guidance, the combination of surface high ridging from the OH VLY
and increasingly dry W/NW flow aloft could support good viewing
locally. Of course, if that front stalls overhead or begins to lift
back to the north during Monday, it would create much more unsettled
weather across the area. For what its worth, the 12Z/14 GFS average
sky cover currently shows mostly clear sky conditions for the area
Monday afternoon.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
As of 12Z...May be a brief period of lingering IFR at KLBT
initially, but otherwise VFR to start the TAF period.
Thunderstorms this afternoon will have the potential to produce
MVFR or lower conditions. A trough approaching from the N and NW
late day and this eve may help to initiate a round of showers
and thunderstorms as well, otherwise we expect VFR condtions to
redevelop this eve. Model profiles support at least the mention
of some low stratus after 08z and did add MVFR BR at KLBT and
KFLO as well. Confidence was too low to introduce an IFR
ceiling late in the valid TAF period.

Extended Outlook...A brief period of MVFR or lower conditions
can not be ruled out in isolated to scattered showers and
thunderstorms Wed through Fri. The risk for flight restrictions
due to showers and thunderstorms will increase on Sat. Low
stratus and some fog during the overnight and early morning
hours may result in flight restrictions as well.

&&

.MARINE...
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NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM Tuesday...Swells from Gert have moved into the
coastal waters but are coming up 1-2 ft lower than previous Wave
Watch guidance indicated. Still expect steep conditions at inlet
entrances, especially when combined with the current during the
falling tide. The local wind wave will add some chop during the
day. Once the sea breeze weakens this evening the flow will veer
to a westerly direction overnight also supported by the eastward
shift of a weak trough.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...Winds Wed morning may be light from the
NW as trough pushes out across the waters. SW winds will return
Wed afternoon, but still less than 10 kt, as a pinned seabreeze
develops. Light and variable winds Wed night and Thu morning
should settle on a SSE to S direction Thu afternoon, still less
than 10 kt, as the seabreeze redevelops and a trough briefly tries
to amplify offshore. Seas will be highest Wed morning, 2 to 3
ft with some residual 4 ft seas across portions of the outermost
waters as Hurricane Gert swell decays. Seas will be 2 ft Wed
night through Thu night.

LONG TERM /FRIDAY THROUGH SATURDAY/...
As of 300 PM Monday...A messy wave spectrum expected late week
as a weak gradient exists in the vicinity of offshore high
pressure. This gradient will gradually tighten beginning late
Friday and on Saturday as a cold front drops into the area from
the NW. Although no wind shift is expected during this period,
speeds will increase, becoming SW at 10-15 kt late Friday and
Saturday, after being SW less than 10 kt. Wave heights will be
2-3 ft Friday with a variety of low-amplitude wave groups
comprising the spectrum. On Saturday seas will build to 3-4 ft
as a SW wind wave becomes more significant.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...High Rip Current Risk through this evening for SCZ054-056.
NC...High Rip Current Risk through this evening for NCZ106-108-110.
MARINE...None.

&&

$$

NEAR TERM...SRP
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...RJD