FXUS62 KILM 191908
Area Forecast Discussion
National Weather Service Wilmington NC
308 PM EDT Thu Jul 19 2018
A low pressure area will develop along the front to the south of
the region and the low will shift up the coast on Friday. This
low will shift to the north of the area on Saturday. A large
upper-level low will shift from the upper plains to the
southeast United State early next week. This will bring
unsettled weather to the region through much of next week.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 3 PM Thursday...The old front remains south of the forecast
area this afternoon, but it will begin to lift back toward the north
as a frontal wave develops late tonight and Friday. As a result, the
chance for showers and thunderstorms will be on the increase over
the next 12-24 hours. Also during this time the precipitable water
will surge above 2 inches, and QPF could easily reach 1-2 inches
along the coast. Scattered to numerous convection and associated
cloudiness will hold temperatures to the mid 80s along the coast and
mid/upper 80s inland. In the meantime, diurnal cumulus will
dissipate early this evening while convective debris flows into the
area from the southwest. The partly cloudy skies will become mostly
cloudy later tonight.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
As of 3 PM Thursday...A wave of low pressure will be moving
along a stalled boundary along the coast Friday night. This low
will lift NE into Saturday morning, pushed up the coast by a
shortwave rotating around the amplifying mid-level trough. As
this feature ejects NE, it will be within a very moist regime
with PWATS of 2.25 to 2.50 inches, suggestive of periods of
heavy rainfall, especially across the immediate coast of NC and
during the first half of Friday night. Much drier air will
advect behind this wave as it lifts away into Saturday morning,
which combined with subsidence behind the mid- level impulse
should keep convection to a minimum much of Saturday. Forecast
soundings show considerable instability Saturday aftn, but very
dry air aloft will likely serve as a lid to most convection
through at least the early evening. Thereafter, things get more
active as an anomalously strong upper low dives out of the Great
Lakes, and these height falls combined with a surface trough
and increasing PVA will allow what could be strong convection to
the west to advect eastward into the CWA late in the period.
SPC has the entire area in a D3 MRGL risk, but attm the threat
for severe looks minimal as most activity will be overnight and
most of the instability appears to be elevated. Will carry TRW-
Saturday night but attm severe threat looks to be too low for a
Highs Saturday will be near climo norms a degree or two either side
of 90 despite abundant sunshine. Mins Friday night will drop to
below 70 well inland, but remain in the low along the coast. More
humid mins are forecast for Saturday night, 72-76, warmest along the
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 3 PM Thursday...an upper-level low over the upper plains will
drop southeast over northern Georgia and retrograding toward the New
Orleans area by middle of the next week. What this means is our
area will be on the east side of this large cut-off low and a
tropical feed will be in place in or near our area through the
period. This will mean good chance of rain each day with
possible heavy rain at times. Confidence is increasing of a wet
period with temperatures slightly cooler through the period.
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
As of 18Z...VFR conditions will prevail through the evening.
Ceilings will lower from south to north as the front positioned
south of the terminals shifts back into the areal. High
confidence in at least reaching MVFR CIGs/VSBYs, especially as
the areal extent of SHRA/TSRA increases during the day.
Extended Outlook...Occasional MVFR to IFR conditions due to
scattered SHRA and TSRA Saturday through Tuesday.
NEAR TERM /THROUGH FRIDAY/...
As of 3 PM Thursday...An easterly fetch will prevail tonight,
likely generating steep 4 ft waves. During Friday a weak frontal
wave will lift northeast up the coast allowing the wind to veer
to a southerly direction during the afternoon. If the low
tracks just inland than winds could be on the low-side by 5-10
knots and seas 1-2 ft. For now favor a blend of models with
slightly less wind during the day. Otherwise, showers and
thunderstorms will increase during tonight from the south,
likely becoming numerous during Friday.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 3 PM Thursday...An area of low pressure moving along the
coast brings some uncertainty into the wind direction and speed
Friday night, but expect this low to strengthen only gradually
so winds will be 10-15 kts from the S and then veering to the
west into Saturday morning as the low pulls away. SW winds then
develop late Saturday and Saturday night, rising to 15-20 kts at
the end of the period. Seas will be primarily wind-wave driven
at 4-5 ft/5-6 sec atop a weak SE swell. This pushes significant
seas to 3-4 ft throughout, with the veering wind causing the
only significant change to the spectrum.
Additionally, the aforementioned low has the potential to bring
heavy rainfall and tstms Friday night, which could produce briefly
lowered visibility and cloud to sea lightning into Saturday morning.
LONG TERM /SUNDAY THROUGH MONDAY/...
As of 3 PM Thursday...With the large upper level-low slowly moving
down from the upper plains to the lower Mississippi valley will
establish a long duration fetch event. During this time period a
southwest to south fetch will be well established over the waters.
Sea will increase from 2 to 4 feet early Sunday morning to 4 to 6
feet by Monday morning and continuing through Tuesday.
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