National Weather Service United States Department of Commerce

 


000
FXUS62 KILM 220734
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
234 AM EST Mon Jan 22 2018


.SYNOPSIS...
Mild January weather will prevail through Tuesday, ahead of an
approaching cold front. Light coastal showers later today, will
be followed by more widespread shower coverage Tuesday, with a
slight chance of a thunderstorm. Cooler air will move in during
the mid-week period, as high pressure builds from the west. A
cold front will approach next weekend, bringing a warming trend,
and a chance of showers Saturday night and Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 234 AM Monday...Subtle and brief mid level ridging will
give way to a southwest flow later today as a mid level cyclone
moves into the Ohio Valley. At the surface high pressure will
keep an increasingly moist southerly flow in place. There may be
a few isolated showers with the surge of warm and moist air
from midday onward but overall guidance has backed off this
activity a bit. The main cold front moves to the western areas
of the CWA by the end of the period and we have maintained the
good chance pops mostly for after midnight moving eastward in
time. Expect balmy temperatures today approaching 70 in some
areas and little cooling by Tuesday morning as some wind keeps
the boundary layer somewhat mixed.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 234 AM Monday...Primary weather caption this period, `Wet
and Mild Tuesday, Turning Cooler and Drier Wednesday`. Showers
and perhaps a TSTM, will be ongoing at the onset of the period,
daybreak Tuesday, and a very blustery and mild start to the day.
Minimums daybreak Tuesday, will elevate to values, that reflect
the normal daytime highs for late January, and dewpoints should
gradually rise to around 60 early Tuesday ahead of the front.
This may allow coastal sea fog to also be an ongoing hazard, as
the mild flow traverses the chilled inshore SSTs. There appears
to be enough CAPE to warrant a slight chance of TSTMs mainly
Tuesday morning. Despite the cool marine layer, elevated, warm
air advection convection is possible, given the kinetic support
aloft. Mid-level lapse rates are mediocre, and this may serve to
limit convective-strength potential.

Clearing trends in wake of the pre-frontal convection, yet prior
to the CAA, will allow a window of downslope trajectories
Tuesday afternoon in mild air, likely bringing many locals into
the 70s. Cold air advection on NW winds will bring lows in the
30s early Wednesday, with a seasonably cool and mostly sunny day
Wednesday, very near normal for January 24th.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 3 PM Sunday...The surface and upper air pattern will be
both progressive and amplifying through Saturday with the ridge
developing in the east. Once surface return flow is established
locally, we should start to see warmer temperatures. It appears
this happens on Saturday. Cloud cover and rain chances then
rise quickly on Sunday with the approach of the cold front and
strengthening upper trough from the west.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
As of 06Z...VFR conditions expected through the first half of
the period then the forecast gets somewhat complex. A warm
front will move across the area around midday Monday ahead of a
stronger cold front that will move across Tuesday. Numerical
guidance is and has been advertising IFR stratus and BR at all
sites in the wake of the warm front. I trended these conditions
in late in the afternoon or early evening at all sites.

Extended Outlook...VFR. MVFR/IFR/LIFR Mon evening/early Tue
aftn.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 234 AM Monday...Very light winds and meager seas
currently reside across the waters. Both will increase
methodically today and moreso tonight as a decent cold front
moves closer from the west. Expect winds of ten knots or less to
increase to 15-20 knots by early Tuesday (possibly a knot or
two higher for a couple of hours). Seas will increase from just
over one foot to 3-5 feet by Tuesday morning. For now do not
expect seas of six feet but it could be close for a couple of
hours. At a minimum a SCEC headline will be necessary this
afternoon.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 234 AM Monday...Tuesday will be a difficult marine day as
SW and W winds gust up to 25-30 KT, prior to a cold front
passage toward evening. This will require a Small Craft Advisory
Tuesday, but it appears winds are strongest ahead of the front,
and in wake of the front Tuesday night and Wed, a diminishing
wind trend can be expected, and thus a short-lived advisory.
Recent numerical wave guidance puts seas at 7 feet 20 miles
offshore Tuesday, from the S every 6-7 seconds. Additionally, a
few TSTMS are possible inshore, and more likely offshore closer
to the west wall of the Gulf Stream. If this were not enough,
inshore waters may face areas of sea fog Monday night and
Tuesday morning.


LONG TERM /THURSDAY THROUGH FRIDAY/...
As of 3 PM Sunday...As a anticyclone approaches Thursday flow
veers to N then NE, possibly becoming light and variable for a
time Thursday evening or early Thursday night as it moves nearly
overhead. E or ESE winds should then increase Friday as this
high begins to share a center with one moving off the New
England coast.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EST Tuesday for AMZ250-
252-254-256.

&&

$$

SYNOPSIS...8
NEAR TERM...SHK
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...SHK