Area NWS Forecast Discussion
000
FXUS62 KILM 180126
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
826 PM EST Mon Feb 17 2020

.SYNOPSIS...
A frontal system will bring a good chance of rain to the area
Tuesday into Wednesday. Cold high pressure will follow late
Wednesday, but a coastal low offshore, should bring rain into
Thursday and possibly some light snow across the area later on
Thursday. Unseasonably cold but dry conditions will arrive for
the weekend, with freezing temperatures likely both Friday and
Saturday morning.

&&

.UPDATE...
Adjusted temps a bit to account for a slight drop before clouds
increase and help to flatten the curve out. Overall forecast on
track with mainly altocu around 8k this evening, but lowering
and thickening overnight with fog and stratus developing. Winds
remain near calm backing slightly to the NE before coming back
around to the SE and S on Tues.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
Most of the low-level stratus has cleared out of our area, with
mid-level clouds beginning to move in from the south. Cloud
cover will increase through tonight, with low stratus again
possible in the early hours. This will help to limit how low
temps get tonight, with current forecast lows in the mid-50s.
Weak surface ridging from the north currently across the eastern
Carolinas will break down early tomorrow, allowing weak
southerly flow to develop and temps rising to the upper 60s.
Rain chances will be on the rise tomorrow, with the best chances
starting tomorrow afternoon into overnight hours, as moisture
will be on the rise throughout the day and a few upper- level
impulses will traverse the area. Bulk of precip will arrive
Tuesday night into Wednesday morning with the passage of a cold
front. Cold front moves through overnight Tuesday, with CAA
lagging into Wednesday, allowing temps to remain steady through
the night around 60 degrees before falling early Wed morning.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
Rain ongoing at start of period, possibly stratiform as leading high
pressure undercuts moist SW flow aloft, with precipitation slipping
just S and E of land zones 12z Thursday, associated with cold
frontal passage.

Concurrently, cyclogenesis off the Georgia coast may aid in
spreading rain northward on Thursday as cold air advection
strengthens, leading to a chance frozen precipitation just beyond
this period into Thursday night. The advent of cold air flux, and
evaporative cooling on Thursday with little sun, likely keeps max-Ts
stuck in the 40s, yielding a cold wet day.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Falling temperatures Thursday night, combined with a good deal of
moisture off shore, north of a developing surface low, and
amplifying coastal trough in vicinity of the coastal waters, should
spread light rain over the forecast area, which would transition to
a period of sleet, then snow, as temperatures continue dropping
late Thursday. Drying will win the battle with precipitation
ending by 12z/7am Friday.

With comparatively mild road/ground temperatures, QPF, and likely
upcoming model changes, cannot commit to accumulations if any, as
yet, but certainly bridges and overpasses, as always, could become
hazardous if precipitation and falling temperatures prevail
through the night, The situation clearly bears watching, and
please stay tuned to future forecasts regarding frozen
precipitation late on Thursday and into early Friday.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
VFR conditions to start with mainly mid cloud deck around 8k ft
into tonight, but near calm conditions will allow IFR stratus/fog
to return after midnight. Tuesday, return flow will begin, with
winds veering to the southwest by late morning, allowing cloud
bases to lift temporarily mainly to MVFR before clouds will
thicken and lower with -RA returning from the S-SW between
19-22z. IFR will return to the TAF sites into Tues night as rain
spreads across the area.

Extended Outlook...MVFR/IFR conditions expected thru Thu Night. This
a result of weak waves of low pressure moving ENE along a stalled
front across the Carolinas. Improving to dominate VFR late Thu night
thru Fri as the stalled front finally pushes south of the Carolinas
followed by strong cold and dry Canadian high pressure.

&&

.MARINE...
Quiet marine weather period through Tuesday night, with
exception being chance for sea fog Tuesday afternoon into
overnight hours as southerly flow develops across the cool
waters. Veering winds between now and Wednesday morning, with NE
winds around 10 kts tonight, easterly winds tomorrow morning,
southerly tomorrow afternoon, and westerly by Wednesday morning
behind cold front. Winds and gusts expected to remain below 15
kts throughout period. Current 3-4 ft seas will decrease to 2-3
ft by tomorrow morning and remain steady through Tuesday night,
combination of a 2 ft 8 sec E swell and a 2-3 ft 5 sec wind
wave. Chance of rain over coastal waters tomorrow afternoon into
Wednesday morning.

Batten down the hatches, this to be a difficult and hazardous
marine period, beginning Wednesday, and ending late Friday, as a
cold frontal passage and an Arctic High impact the waters. Gale
force winds gusts are beginning to look likely, late Thu to
early Fri, so a Gale Warning is possible during this time. Rain
will reduce marine visibility Wednesday and again Thursday and
Thursday night. Bitterly cold air late Thursday, may result in
periods of sleet and eventually a chance of snow near the coast
Thursday night and very early Friday. Gale force gusts and a
potential for low visibility makes this possibly a dangerous
marine period. Latest wave height forecast bulletins, show buoy
41013, Frying Pan Shoals, shows 10-11 foot NE waves every 9
seconds Thursday night and early Friday.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.

&&

$$
SYNOPSIS...ILM
UPDATE...RGZ
NEAR TERM...VAO
SHORT TERM...MJC
LONG TERM...08
AVIATION...RGZ
MARINE...MJC/VAO

NWS ILM Office Area Forecast Discussion