Area Forecast Discussion
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FXUS62 KILM 221912
Area Forecast Discussion
National Weather Service Wilmington NC
312 PM EDT Sat Oct 22 2016
Seasonably cool weather continues Sunday followed by a brief
warm- up Monday. A reinforcing shot of dry and cool air Monday
night will set the stage for dry weather and seasonable
temperatures for much of the upcoming week. A low pressure system
will approach the area late next week.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 3 PM Saturday...Low level jetting and surface pressure
gradient continue to relax and the breeziness seen across the area
due to deep mixing will abate close to sunset. Clear skies and light
(but not calm) winds will allow places to radiate into the lower 40s
according to tightly clustered MOS guidance numbers.
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
As of 3 PM Saturday...Although tomorrow will only be a few degrees
milder than today it will feel moreso due to the lack of today`s
gusty breezes. The center of the surface ridge ends up to our south
by evening at which time we will see a light S to SW wind. Boundary
layer temperatures will be recovering so Sunday night lows will be
in the mid to upper 40s despite the continued light winds and clear
sky. Warm advection strengthens on Monday ahead of a cold front and
afternoon temps should shoot nicely into the upper 70s. This
moisture-starved boundary comes through Monday evening. The gusto of
its cold advection will not match that of the previous cold front
keeping Monday night`s lows seasonable.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 3 PM Saturday...Surface high building in from the north at the
start of the period will gradually shift east during the week. Cool
northeast flow at the surface Tue and Wed will veer to southeast Thu
as the ridge axis moves off the coast. At this point the forecast
becomes less clear due to uncertainty with respect to the evolution
of the upper pattern. Early in the week 5h trough lifts northeast
and weak ridge builds east. Period of ridging is short lived and by
Thu afternoon/evening the 5h shortwave ridge will be replaced by
troughing associated with 5h shortwave crossing the Great Lake/OH
The uncertainty during the second half of the period stems from the
strength of the 5h trough Thu/Fri. Both GFS/ECMWF solutions drive a
cold front into the area late Thu night or Fri but the amount of
forcing and moisture differs. GFS is less amplified and drier while
the ECMWF is showing more amplification of the 5h trough and
increased moisture as well as much better precip chances. Compromise
between the 2 solutions matches up well with the inherited forecast
as well as the offerings from WPC so for now will continue to carry
slight chc to low chc pop Late Thu and Fri with drier and slightly
cooler conditions for Sat. However, temps Sat would still be above
normal as both solutions lack strong cold advection.
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
As of 18Z...High confidence in VFR through the valid TAF period.
Expect NW winds of 10 to 15 KT with higher gusts to drop to around
5 kt after sunset.
NEAR TERM /THROUGH TONIGHT/...
As of 3 PM Saturday...Advisories to drop out during the near term
as winds and seas abate. This trend should be less pronounced over
the water compared to land as weak low level jetting reforms over
north-central NC and the chilly airmass flowing atop the warmer
water tries to grab some of that momentum. The offshore flow has
really beaten the bigger waves out to sea as even 41013 has
already fallen just below 5 ft, albeit a choppy 5.5 sec dominant
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 3 PM Saturday...Wind and seas subside a bit early Sunday as
the ridge axis moves across but then picks up later in the day. At
this time no advisories or even cautionary headlines appear
necessary. Monday brings back a diminishing trend as the surface
trough associated with a cold front becomes rather diffuse,
weakening the gradient. FROPA will bring a sharp veer to N or NNE
but not a significant surge, again precluding any headlines.
LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 3 PM Saturday...Pinched gradient Tue morning in the wake of
the exiting cold front will keep northeast flow 15 to 20 kt into
Wed. Gradient slowly relaxes and by Wed northwest winds will be 10
to 15 kt. Surface ridge axis shifts off the coast Thu with winds
veering to southeast. Gradient remains light with speeds staying
around 10 kt. Seas 2 to 4 ft Tue and Wed drop to 2 to 3 ft Thu.
NC...Coastal Flood Advisory until 5 PM EDT this afternoon for
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for AMZ254-
Small Craft Advisory until 9 PM EDT this evening for AMZ250-