Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
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FXUS62 KILM 190105
Area Forecast Discussion
National Weather Service Wilmington NC
805 PM EST Wed Jan 18 2017
Weak high pressure will build over the region tonight and
Thursday. Low pressure and its associated front will impact the
area late Thursday night and on Friday. A brief period of weak
high pressure on Saturday will be followed by a strong area of
low pressure which will move across the deep south and bring
gusty winds and possibly strong thunderstorms to the Carolinas
late Sunday into early Monday. Dry conditions will return
Tuesday and Wednesday as mild high pressure builds in from the
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --As of 730 PM Wednesday...Currently a N to NE dissipating surge
is pushing across the coastal Carolinas, this after the initial
NW surge from earlier in the day associated with the CFP itself.
Will see winds veer to the N to NE across the entire ILM CWA
this evening, along with a general diminishing trend overnight.
Places may go calm as the highs center moves closer to the FA
from the NW. Sfc dewpoints have and/or will drop and remain in
the 30s overnight via from initially drier air aloft mixing
down and now associated with the change in airmass itself.
Tonights lows only tweaked from quick look at 18Z various model
Mos guidance. Looking at mainly thin Cirrus advecting overhead
tonight...thus mostly clear for sky conditions.
As of 3 PM Wednesday...Clouds dispersed a little quicker than
forecast/modeled making for a sunny and warm afternoon albeit a
breezy one at times. By evening low level wind barbs will line up
with isotherms shutting off the cool advection behind the front
leaving tonight`s low temperatures about 10 degrees above
climatology despite a lightening wind and continued clear skies.
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.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday... Upper ridging and weak surface pattern to
bring a sunny start to Thursday. Late in the day a few clouds will
move in from the SW ahead of the next system and the ridging aloft
moves off the coast. Highs in the low 60s while cooler than today
are still almost 10 degrees above normal. A more precipitous
increase in moisture is slated for Thursday night. Models have been
slowing with the arrival of rain chances Thursday night. It now
appears that most of the rain is slated for Friday with a weak warm
front and mid level shortwave. QPF prospects appear marginalized by
the deepest mositure being shunted well to our north.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 3 PM Wednesday...Weak mid level ridge axis will move offshore
Sat, tapping GOMEX moisture for the start of next week. Strong
southwest flow, 300 mb jet exceeds 100kt at times, ahead of
deepening southern stream system will spread deep moisture over the
southeast. Precipitable water values will exceed 1.5 inches at times
but there will also be some wrap around dry air to contend with.
Strong low level jet, especially later Sun and Sun night does still
pose a severe weather threat, but both the GFS and ECMWF have
trended slightly faster with the system. Strong, veering winds ahead
of the front, which is now progged to pass Mon morning, will lead to
an abundance of shear but instability will be lacking. 850mb jet Sun
night is likely to exceed 50 kt, which if mixed to the surface would
likely result in at least a few severe storms. However, mixing will
be the problem, especially given the nocturnal timing. So while
severe weather cannot be ruled out it is more likely to be an
isolated occurrence as opposed to a widespread event.
Stacked low passes over the area Mon into Mon night. Diurnal
convection is likely, mainly in the form of isolated showers and
thunderstorms, as the cool core of the low moves into the area
during peak heating. Trough may become negatively tilted as it
exits the region Mon night but it is not likely to have an
impact on the forecast area. Mid level ridging and weak high
pressure will follow the exiting system and linger over the
southeast through mid week. The surface high has origins in the
southwest with little to no cold air present. Temperatures
through the period will remain above to well above climo.
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As of 00Z...High confidence for VFR conditions through the forecast
period. High pressure will continue to build in from the northwest
through Thursday afternoon. Light northerly flow overnight with
northeasterly flow on Thursday. Time height shows dry air at all
levels into Thursday morning, with perhaps some cirrus over the
southern portion of the CWA.
Extended Outlook...IFR ceilings are possible inland in low
stratus Friday night as the next warm front and rainfall event
develops. IFR ceilings could continue into Saturday morning.
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 730 PM Wednesday...The north to northeast surge dropping
down the NC Coast has lost much of it`s zest as it pushed past
Cape lookout to the Cape Fear region early this evening. Could
see a few 20 kt wind gusts across the ILM NC waters but that too
will dwindle in magnitude. The pre-dawn Thu hours will see a
more stable N to NE wind at 10 to occasionally 15 kt.
Significant seas initially in the 2 to 4 foot range, with the 4
footers across the ILM NC Waters early, will subside to 2 to 3
ft thruout overnight. Wind driven waves at 4 to 5 second periods
will dominate the seas. The easterly ground swell affecting the
local waters for more than a week has finally degraded to the
point where it is no longer identifiable.
As of 3 PM Wednesday...Cold front will turn winds to N this
evening and set up an abating trend as the gradient eases.
Nearshore seas will settle most quickly due to the turn from
coast-parallel flow to offshore with wave shadowing, even
though their faces/periods may steepen/shorten. Most places
will open up a bit in wave height, ending up generally with a
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 3 PM Wednesday...Pretty minimal wind and seas Thursday as
a weak high builds in from the north. This will initially bring
a light NE wind but as the high moves off the coast they will
veer in direction. A light SE flow Thursday night could allow
the daytime 2 ft waves to shrink even further. A warm front will
turn the wind to SW by Friday with no significant increase in
wind speed so waves won`t change much.
LONG TERM /SATURDAY THROUGH MONDAY/...
As of 3 PM Wednesday...Surface and mid level ridging will shift
off the coast Sat, leaving light southerly flow over the
waters. Speeds will remain 10 kt or less into Sun before
starting to increase ahead of approaching storm system. Well
developed storm will move across the southern states Sun and
Mon, increasing low level southerly flow to a solid 20 kt Sun
night and Mon. Front associated with the low will move across
the waters late Mon with winds veering from south- southeast to
southwest late Mon and Mon night. Cold air is lacking but
gradient will keep winds 15 to 20 kt through the end of the
period. Seas 2 to 3 ft Sat into Sun start to build in response
to the increasing southerly flow. SCA headlines will likely be
needed Sun night and could continue through the end of the
period with seas approaching 10 ft at their highest.
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