Scientific Forecaster Discussion
fxus62 kilm 171944
Area forecast discussion
National Weather Service Wilmington NC
244 PM EST Wed Jan 17 2018
a cold front will bring a mix of rain and snow, and will clear
the coast late tonight. Cold and dry Arctic air, will spread
into the region through Thursday. Temperatures will warm into
the weekend as high pressure moves offshore. Another cold front
will bring rain chances by Monday evening, but little cooling,
and temperatures are expected to remain above normal into next
Near term /through Thursday/...
as of 3 PM Wednesday...a Winter Storm Warning continues for
Marlboro and Robeson counties, and a Winter Weather Advisory
remains in effect for Darlington, Marlboro, Bladen, and Pender
GOES-east water vapor is showing the mid-level trough moving
into the western Carolina's. At the surface the cold frontal
boundary is entering into the western portions of the forecast
area. The 2 PM observations is showing rain over most of the
forecast area. The latest hrrr is showing the best chances of
snow in the western half of the area after 3 PM and will slowly
make it to the coast. Timing for the coast appears to be after 8
PM. With the dry air it appears after the initial shot of
precipiation that we will see light snow or flurries well after
Also, with delay in the system making eastward have extended the
warnings and advisories to 1 am. Also, for areas south of the
warning and advisory area will have to watch for black ice as
any liquid precipiation that does fall will likely freeze.
As the storm pushes off the coast, winds will increase and
combined with the low temperatures will see wind chills in the
the 8 to 13 degree range around sunrise Thursday. This is just
above the Wind Chill Advisory criteria.
On Thursday skies will clear but temperatures will struggle to
get to 40 degrees with brisk winds.
Short term /Thursday night through Friday night/...
as of 3 PM Wednesday...the mid level pattern will have evolved
into a split flow regime initially and translate into a
southwest flow ahead of a mid level low by Saturday morning.
Although seemingly busy at the mid levels, surface high pressure
will be the dominant feature. This high will move across the
Gulf of Mexico then out into the Atlantic by the end of the
period. Once again a temperature forecast throughout and expect
lows Friday in the lower to middle 20s. Highs Friday will
rebound into the 50s.
Long term /Saturday through Wednesday/...
as of 300 PM Tuesday...the chief caption this period ? "Warming
trend". Even in wake of a cold front early next week, minimal
cold air advection is seen, as the upper pattern sees a southeast Atlantic
upper ridge gradually expand northwest into the area. A weak cold pool
aloft meanders eastward along the Gulf Coast this weekend and
offshore by Monday, will little sensible weather impacts here.
As a result, much of next week may feature sunshine and 60s in
the afternoons, likely feeling like an early Spring compared to
the recent weather pattern. Aside from late Monday and early
Tuesday, this entire period will maintain a dry column and low
precipitable water values. The coldest period, will be Saturday morning, near
freezing, the mildest, perhaps just ahead of the cold front
Monday into the upper 60s by afternoon. Tuesday looks to be the
breeziest day in wake of the cold front, with west-northwest breezes.
Aviation /19z Wednesday through Monday/...
as of 18z...things will be going downhill for the inland
terminals pretty quickly. The precip will start out as rain, but
with 850 temps dropping to around -5c, it will turn to snow,
perhaps moderate for an hour or two. Time height shows that the
moisture column is not very deep on the back end, so there will
probably two or three hours of flurries, with little additional
accumulation. Ilm will be the last terminal for the snow to end,
probably around 5-6z. Gusty winds and cold air advection will
be the rule from 02z through most of the forecast period. Nearly
clear skies by daybreak on Thursday. Aside from late Monday and
early Tuesday, this entire period will maintain a dry column
and low precipitable water values. The coldest period, will be Saturday
morning, near freezing, the mildest, perhaps just ahead of the
cold front Monday into the upper 60s. Tuesday looks to be the
breeziest day in wake of the cold front,
near term /through Thursday/...
as of 3 PM Wednesday...currently winds are from the east with
seas running 3 to 4 feet. This will change quickly as the
front and a developing low shifts to the northeast off the
coast. Winds are expected to reach 20 to 25 knots late this
evening and seas will increase to 5 to 7 feet. The winds will
weaken and with an offshore flow the seas should settle back out
to 3 to 5 feet by Thursday afternoon.
Short term /Thursday night through Friday night/...
as of 3 PM Wednesday...surface high pressure will move from the
northern Gulf of Mexico to well offshore during the period.
Between this feature and the general cyclonic flow to the north
a west to southwestern flow will prevail across the waters. Wind
speeds will be fairly uniform in a 10-15 knot range leaning
moreso toward the higher end early then the lower end late.
Significant seas will generally fall into a 2-3 foot range.
Long term /Saturday through Monday/...
as of 3 PM Wednesday...welcoming and friendly marine conditions
this period, particularly in wake of recent weather. As high
pressure slips offshore by the weekend, a milder return SW flow
will prevail, with seas 3 feet or less, and even 1-2 feet at
times, with winds less than 15 kt. Seas will begin to build
Monday as sustained southeast fetch offshore, starts pushing wave
energy toward our coast. By Monday night seas of 4-5 ft in 7
second intervals, may be rolling in. No thunderstorms this period, but a
few rain showers can be expected Monday night, as a cold front
crosses the coast. Inshore water temperatures were in the upper
40s to lower 50s.
SC...Winter Weather Advisory until 1 am EST Thursday for scz023-024.
Winter Storm Warning until 1 am EST Thursday for scz017.
NC...Winter Weather Advisory until 1 am EST Thursday for ncz096-105.
Winter Storm Warning until 1 am EST Thursday for ncz087.
Marine...Small Craft Advisory from 7 PM this evening to 7 am EST
Thursday for amz254-256.
Small Craft Advisory from 7 PM this evening to 1 PM EST
Thursday for amz250-252.