Area Forecast Discussion
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FXUS62 KILM 170053
Area Forecast Discussion
National Weather Service Wilmington NC
753 PM EST Mon Jan 16 2017
A warming trend will occur Tuesday and Wednesday ahead of a
cold front which will drop south through the Carolinas late
Wednesday. Cooler and drier high pressure will follow on
Thursday. Low pressure moving up from the Gulf coast will
drag a warm front through the area on Friday. High pressure
will build in on Saturday before another system brings
unsettled weather for Sunday.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 730 PM Monday...Included patchy light rain during a
portions of this evening into the overnight period...mainly
along and west of the I-95 corridor. Also, included showers
over the adjacent coastal waters with a few possibly raking
across Bald Head Island. Upped the cloud cover to mostly
cloudy or completely overcast via latest Satellite imagery
trends and 18Z model data. Included patchy to areas of fog this
evening and overnight given latest sfc obs trends and locally
run fog algorithm. Low stratus to affect the ILM CWA Carolina
Coasts and adjacent waters and refrained from indicating sea fog
at this juncture with the difference between sfc dewpoints and
SSTS not large enough. Temps tonight will either hold steady or
drift slightly lower from current values thru this evening and
overnight. Basically, Not your normal diurnal temp curve.
As of 300 PM Monday...Weak isentropic upglide will lead to a
cloudy night but the ascent appears to be too weak and gently
sloped to generate any precipitation. The temperature curve
(which was troublesome this will be quite flat inland or even
rise a bit overnight. Most guidance not really indicative as
such again likely due to the weak nature of the thermal
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 300 PM Monday...For as weak as the aforementioned near
term warm advection is Tuesday will sure turn out a mild
afternoon. This will be more a function of not being trapped
under a deep and moist inversion. The moisture will not be
completely eroded however as forecast soundings show some
lingering moisture in the 3-5kft layer as well as above about
7500ft. The high level moisture in particular probably lingers
Tuesday night and then low level moistening gets underway
Wednesday compliments of approaching cold front. Timing
differences with respect to the front are affecting
temperature guidance with the slower WRF allowing for an even
warmer afternoon than the quicker GFS. Stayed closer to the
lower values due in part to support from the EC. Any
significant rainfall will stay north of the area underneath the
upper trough though a few sprinkles or stray hundredth of an
inch or three cannot be ruled out locally.
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 300 PM Monday...Unsettled remains the operative word
for the extended period courtesy of a highly amplified and
shortwave laden pattern.
The first significant system for the eastern Carolinas arrives
late Thursday into early Friday via a shearing mid level system
moving across the Tennessee and Ohio valleys. A weak occluded
front is paired with this system as is a stationary front to the
south but these have little impact on the sensible weather.
Overall the inherited chance of showers still looks good.
The second more potent system at least to this point arrives late
Sunday into early Monday via a more powerful and closed shortwave
traversing a similar path to the first system. This system
continues to strengthen via the medium range guidance with good
moisture advection from the Gulf of Mexico and Atlantic.
Combined with good difluence aloft the elements for a soaker are
in place. Citing the dynamics, a high shear/low cape convective
event is possible with plenty of details to be determined in
the coming days.
The temperature forecast has shown little change with the latest
guidance and with a moisture laden period (even outside of pops
plenty of cloud cover) there shouldn`t be much diurnal variation.
Expect highs generally in the 60s and lows in the middle to upper
40s with some areas (generally coastal and southern) not dipping
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 00Z...Expect MVFR/IFR conditions this evening to become
IFR/LIFR for the overnight hours as stratus allows for low cigs
to become widespread, with patchy areas of fog as well. Light
northeasterly winds will prevail. On Tuesday, anticipate
deteriorated conditions to continue through midday, with a
gradual improvement to VFR as cigs lift by the late afternoon
hours as winds become west-southwest, around 5 to 10 kts.
Extended Outlook...Cold front Wednesday, accompanied with
showers and MVFR. Showers possible Friday. Otherwise expect
NEAR TERM /THROUGH TONIGHT/...
As of 730 PM Monday...A stalled boundary extending inland in
the vicinity of South Santee River has hooked up with an
inverted sfc trof of low pressure just offshore and parallel to
the Carolina Coasts. The 2 boundaries as a whole will begin
lifting northward overnight into daytime Tuesday. This sfc
pressure pattern and rather relaxed sfc pg will for the most
part produce NE winds at 10 to 15 kt, veering to the ENE to ESE
around 10 kt by daybreak.
Significant seas will run 2 to 3 ft. A degrading ESE 1 to 2
foot ground swell at 9 second periods will combine with locally
produce wind driven waves at 5 to 6 second periods. Power-wise,
the locally produced wind driven waves wins this round.
As of 300 PM Monday...Winds to grow lighter all night as high
to our north lifts out and frontal boundary advances northward.
There may be some variability in wind direction late in the
period as a light southerly flow component tries to get
established. Seas will average 2 to 3 ft.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 300 PM Monday...With the warm front lifted out to our
north on Tuesday the gradient will remain quite weak. SW flow
will be capped at just 10kt and seas may drop to just 2 ft. The
approach of a cold front will veer and increase the flow
gradually Tuesday night and then moreso Wednesday. This front
may pass through either midday or late afternoon Wednesday. The
cooler surge behind this boundary is tempered enough that no
headlines likely follow its passage.
LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 300 PM Monday...Expect essentially light and variable
winds Thursday via a weak pressure pattern. Wind fields will
show a little better definition late Thursday into Friday as a
southwest flow develops ahead of a weak front. Speeds increase
briefly to 10-15 knots. By Saturday a weak northerly flow
develops. Significant seas will be 2-4 feet as the weak wind
fields and fetch change keep them somewhat in check.