Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
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FXUS62 KILM 201918
Area Forecast Discussion
National Weather Service Wilmington NC
318 PM EDT Thu Oct 20 2016
Mild weather will prevail through Friday before chillier air
behind a cold front comes crashing into the eastern Carolinas
Friday night. The weekend will be characterized by seasonably
cool temperatures with lows in the 40s and highs remaining below
70 degrees Saturday and Sunday. A brief warm-up Monday will be
followed by a reinforcing shot of dry and cool air Monday night.
This will set the stage for dry and fair conditions in the
upcoming week with temperatures near normal for the season.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 3 PM Thursday...Sea-breeze has worked its way inland with the
the easterly flow in the lower levels. The high temperatures have
reach the mid 80s inland and the marine influence show temperature
in the upper 70s at the coast. For the overnight, mostly clear skies
and lows tonight will range from the lower 60s inland to the mid to
upper 60s at the immediate coast. Overnight, there will be a battle
between patchy fog and/or possible stratus developing with a slight
hint of a low-level jet developing overnight.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
As of 3 PM Thursday...Friday: NAM and GFS continue to be close on
timing of cold front that will sweep across the forecast and bring
the first taste of fall weather for the region this year.
The anafront structure of the cold front continues to be simulated
by the models which means most of the precipiation will be at or
behind the front which will enter the forecast area at or about 18
utc and exit the coast before 00 utc. If this timing is correct and
the precipitable waters are correct showing values decreasing
rapidly after the frontal passage, then the amount of qpf with this
system will be limited, < 0.10". Finally most of the energy with the
system is north of our area so this is another hint the chances of
the convection appear limited.
Friday night through Saturday night: the models continue to show
strong cold air advection with NAM and GFS time heights showing 12
hour temperature changes of less than -10C air moving into the area
late friday into saturday. This will result with lows falling into
the mid to upper 40s Friday night and lower 40s to around 40. The
GFS MOS is even showing a low of 39 at LBT Saturday night. At this
time it does not look like we will break in low temperature records.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 3 PM Thursday...The salient headline banner this period
displayed in the colors of fall reads `Mainly Clear with Autumn
like Temperatures`. Seasonably cool air Sunday pooled across the
area will rebound briefly Monday ahead of an approaching dry cold
front Monday night. In wake of a clipper wave Monday resurging
surface high pressure will escort a refreshing exchange of cool
and continentally thirsty air across the Carolinas early Tuesday.
This will present dry conditions co-joined by seasonable temps
Tuesday through Thursday. The coolest portion of this period is
the very onset daybreak Sunday. The mildest period remains Monday
afternoon ahead of the dry frontal transit. Sunshine minutes will
be flirting with maximum attainable values this period.
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
As of 19Z...VFR conditions will prevail through the evening then
the development of fog and stratus overnight will lead to
MVFR/IFR conditions. CIGs and VSBYs will improve after 13Z Friday
with increasing southwest flow ahead of the cold front Friday
Extended Outlook...Potential for brief MVFR CIGs in the vicinity
of widely scattered SHRA and isolated TSRA Friday afternoon.
Otherwise, expect VFR to prevail Sat-Tue.
NEAR TERM /THROUGH TONIGHT/...
As of 3 PM Thursday...Light east winds under high pressure with wind
waves running around 2.5 feet with a 1 ft swell from the southeast.
As a cold front approaches from the west, a narrow high pressure
ridge and a developing low pressure area well off the coast will
continue to produce east to northeasterly winds that will increase
to around 10 knots.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 3 PM Thursday...Friday through Friday evening: A cold front
will cross the waters on Friday afternoon. Winds will be from the
southwest to west southwest at 10 to 15 knots ahead of the front,
but behind the front is a different story. Cold air advection will
be strong behind the front and northwest winds of 15 to 25 knots
will occur with higher gust. Seas will increase to 4 to 7 feet at
20 miles off the coast but with an offshore flow the seas will be
2 to 3 feet. The winds are expected to relax later Saturday. A
small craft advisory for these conditions are possible Friday
night into Saturday. Winds will diminish some Saturday night as
the sfc pg loosens a bit. With the center of the high progged to
be over the Gulf coast states by Sun morning, winds across the
area will remain active.
Saturday and Saturday night: Wind and seas are expected to relax by
Saturday evening with a north west wind of 15 knots and seas
subsiding to 2 to 4 feet overnight Saturday.
LONG TERM /SUNDAY THROUGH TUESDAY/...
As of 3 PM Thursday...Light to moderate WSW-W winds Sunday and
Monday will be replaced with an uptick in NW winds as a dry cold
front brushes offshore Monday night. The re-newed cool air surge
should bring NW gusts to at least 20 KT Monday night turning N_NNE
Tuesday with 20 KT gusts still in the mix. Thus it appears at a
minimum an `Exercise Caution` headline may be needed, with
`Advisory` marine conditions approached. The fact that sea surface
temps are in relative contrast to the cooler air should promote
efficient mixing of the lower atmospheric winds, and gusts to 25
KT cannot be discounted as improbable. No TSTMS this period nor
restrictions to visibility. Manageable and friendly seas Sunday
and Monday will turn more challenging Monday night and Tuesday as
the wind-wave portion of the sea spectrum take grip of the sea.
As of 3 PM Thursday...The tide is falling downtown this afternoon
and the coastal flood warning will be cancelled once the river level
has fallen below the 5.5 ft level. The water level anomaly was
approximately 1.3 feet which saw the river fall just short of the
moderate flooding downtown. Definitely a good sign. Water levels
are forecast to flirt with the moderate flood thresholds during
the next few afternoon tide cycles, which is greater than or equal
to 6.7 ft MLLW. The overnight tide cycles are expected only to
fall short of the 6.7 ft level so expect coastal flood advisories
to be issued overnight.
High Tide Times and the forecast water level for the downtown
2:22 AM on Fri Oct 21...6.0 ft MLLW.
2:57 PM on Fri Oct 21...6.4 ft MLLW.
3:23 AM on Sat Oct 22...6.0 ft MLLW.
Here are the flooding thresholds based on the downtown Wilmington
Gage on the Lower Cape Fear River...
Minor flooding......5.50 ft MLLW to 6.69 ft MLLW.
Moderate flooding...6.70 ft MLLW to 7.99 ft MLLW.
Major Flooding......8.00 ft MLLW
As of 3 PM Thursday...The ASOS at the Lumberton, NC airport (KLBT)
has no power and the emergency generator which had maintained power
since Hurricane Matthew has run out of fuel. LBT is awaiting a
fresh supply of fuel so the equipment can be up and running again.
Observations and climate data from Lumberton will remain missing
until further notice.
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