Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 231727
Area Forecast Discussion
National Weather Service Wilmington NC
127 PM EDT Sun Oct 23 2016
Chilled air this morning will warm up close to or around 70
degrees this afternoon. Clear nights and Sunny skies will be on
tap through the mid to late week period. A brief warm-up on Monday
will be followed by a dry cold frontal passage late Monday
afternoon and evening. a reinforcing shot of cool air will
infiltrate the area complements of Canadian high pressure ridging
southward from it`s center north of the Great Lakes. Another
warmup will occur towards the end of this work week.
.NEAR TERM /THROUGH TONIGHT/...
As of 1045 AM Sunday...With 12Z area RAOBS showing PW values of
about a quarter of an inch its no surprise that it`s a `temperature
only` forecast today. Latest MOS supports our forecast and so no
changes are planned at this time. Previous:
As of 630 AM Sunday...Upper longwave pattern in place now. This
means Autumn season is fully upon the ILM CWA. At the sfc, high
pressure will remain parked across the Gulf Coast States this
period. The sfc ridge axis will extend from it`s center toward the
northeast and across portions of the ILM CWA today. For tonight,
it`s axis is shunted southward. This positioning today, will
result in nw-w winds at 5 to 10 mph, it`s shunted position and a
slightly tightened sfc pg tonight will keep sw to w winds active.
Another issue will be the low level jet just off the surface.
Models indicate 25 to 30 kt west winds, with some of that mixing
down to the sfc. Do not expect any decoupling of the winds
tonight. This may also keep min temps up even hier than what the
consensus of the avbl mos guidance is indicating. In fact, will
have temps drop to near the fcst lows just after midnight, and
then will indicate steady or slowly rising temps there-after. This
also is indicative of the start of WAA, ie. 850mb temps
increasing this period along with 1000-850mb thicknesses.
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...WAA ahead of the approaching cold front will
be ongoing at the start of this period. Could see occasional thin
cirrus clouds traversing the ILM CWA thruout this period via model
rh time height displays across the FA. With WAA, consensus amongst
the models gives mid to upper 70s for highs on Mon. The cold
front, a dry one, with very little clouds associated with it by
the time it reaches and drops south across the ILM CWA. Time line
for thIS cfp will run from late Mon afternoon thru early evening.
This cfp will not be as dramatic as it`s predecessor a couple days
ago, but will re-enforce the cool air across the FA for the
remainder of this period. This due to sfc high centered north of
the Great Lakes, ridging southward across the ILM CWA and
continuing across Georgia. Thus, an influx of COOL Canadian air
will occur for Tue thru Wed.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 230 AM Sunday...Quintessential autumn weather Wednesday
will transition to a brief but weak warm sector regime late
Thursday and Friday as an approaching short-wave and attendant
surface low begin to erode locally an entrenched high pressure
wedge. This should generate a bit of cloud cover late week and
perhaps -RA/-SHRA respectively prior to frontal passage sometime
Friday. No appreciable QPF is expected to be laid down since
return flow and low level wind trajectories remain unfavorable for
notable moisture advection. This will however bring slight cooling
into next weekend but not as cool as we are seeing this weekend in
terms of minimum readings. As a result we expect the river levels
to continue a decline through the extended period.
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --As of 18Z...VFR likely through the TAF valid period. Nearly ideal
flight conditions today with clear skies and unlimited visibility.
W-NW winds 5 to 10 knots will back to the W-SW. Aft 00Z winds will
initially become LGT and VRBL, but will resume from a SW direction
around 5 kt for the overnight hours.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/... As of 1045 AM Sunday...No changes to
the forecast at all. Previous discussion follows:
As of 630 AM Sunday...Surface high will ridge across the waters
from it`s center over the Gulf coast states. This will result in
a loosened sfc pg with a diminishing nw windS later today. For
tonight, a low level westerly jet at 25 to 30 kt just off the
deck, will occasionally mix down to the ocean sfc. Have indicated
w to sw winds increasing slowly thru tonight. Significant seas
will mainly be driven by locally produced wind driven waves at 3
to 5 second periods. There will be an underlying easterly 1 foot
ground swell at 9 second periods. Overall, seas 2 to 5 ft today
and holding in the 2 to 4 ft range tonight. Due to the nw to w
wind directions, a limited fetch will exist.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...For this period, a slightly tightened sfc
pg to occur Monday ahead of an approaching cold front. This will
yield sw to w winds at 10 to 20 kt. A dry cold frontal passage
expected, with it dropping south across the local waters by early
Monday evening. After fropa, winds will become ne at 10 to 20 mph
with a few hier gusts. This due to the combined efforts of a
tightened gradient and CAA. Sfc ridging from the highs center
north of the Great Lakes will extend across the Carolinas thru the
remainder of this period along with the ne winds that will
partially diminish Tue night into Wed. Significant seas will
primarily be ruled by locally produced wind driven waves at 4 to
6 second periods. Significant seas to range between 2 to 5 ft,
with a few 6 footers possible early tue off Cape Fear and Romain
respectively. SCEC conditions may be met late Mon night thru Tue.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
As of 230 AM Sunday...Moderately bumpy seas should be anticipated
Wednesday since PMSL contours will remain somewhat packed closely
together over the 0-20 NM waters. An exercise caution statement
cannot be ruled out entirely even though various wave solutions
cap seas at around 4 feet accompanied by fresh NE breezes. Vast
improvement Thursday afternoon and Friday as a flat pressure
pattern sprawls over the Carolina waters. NO TSTMS or constraints
to visibilities are expected this period. A few light showers may
touch Cape Fear Friday as a front transfers off the coast.