Area Forecast Discussion
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FXUS62 KILM 221031
Area Forecast Discussion
National Weather Service Wilmington NC
631 AM EDT Wed Mar 22 2017
A cooldown gets underway today as high pressure builds in
through Friday from the north. As this high moves more offshore
over the weekend a warmup will ensue. Minor rain chances are
expected Sunday as a weak upper disturbance passes well to our
.NEAR TERM /THROUGH THURSDAY/...
As of 300 AM Wednesday...That was quite an MCS we had overnight!
Reports of damaging winds within our forecast area have been limited
to Darlington County, although we wouldn`t be surprised if damage
also occurred across Dillon or even western Robeson counties.
Reports typically trickle in after sunrise, so look for LSRs to be
issued if and when we receive any additional reports.
A wave of low pressure associated with the MCS will move off the NC
coast by 5 AM. A cold front moving southward behind the low will
sweep across southeastern NC and northeastern SC shortly thereafter.
Drier air already in place across southern Virginia will spread
southward, eroding any remaining low clouds by early afternoon.
Breezy northeast winds will gust to 25 mph most of the day as low-
level lapse rates steepen due to sunshine and cold advection. Highs
should reach the lower-mid 60s over SE North Carolina, and 66-72
over NE South Carolina.
Tonight: for the fifth time this month the airmass will become
unseasonably cold and bring the potential of one or potentially two
nights of freezing temperatures. A freeze watch has been issued for
Pender and Bladen counties where the best potential of freezing
temperatures will exist. Despite winds remaining in the 4-8 mph
range for most locations overnight, 850 mb temps falling to 0C to
-2C across SE North Carolina should result in low temperatures in
the 30s for all but the immediate coast of South Carolina. Average
temperatures this month have run around 4 degrees below normal, with
multiple freeze events turning March 2017 into a nightmare for local
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 300 AM Wednesday...Canadian high pressure over the Great Lakes
will move down to the Mid-Atlantic coast Thursday, then offshore
Friday. After a partly sunny and chilly day Thursday (highs only 55-
60) a gradual modification of the airmass will occur beginning
Thursday night with 850 mb temps forecast to rise by several degrees
as winds at this level turn southwesterly. Good radiational cooling
Thursday night along with higher dewpoints will produce the
potential for frost across the normally colder peat/pocosin areas of
SE North Carolina. Depending on later forecasts, a Frost Advisory
may be needed for at least Pender and Bladen counties.
By Friday the surface high should be far enough offshore to allow
southeasterly winds to develop across the entire area. Warmer and
more humid air will spread onshore and highs should reach 70 degrees
inland from the coast.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 300 AM Wednesday... Return flow underway on Saturday expected
to bring unseasonable warmth. Upper ridge axis should stay close
enough to the coast to keep mid levels fairly dry. This changes
fairly quickly Saturday night into Sunday and moisture depth may
increase. Two large shortwaves try to impinge upon our upper ridge
but appear to largely be shunted over it to the north. It appears
that late period moisture depth may actually decrease. So while some
minor late weekend rain chances may materialized they should dwindle
heading into next week. Daytime highs will remain above climo,
generally in the mid to upper 70s but trending towards 80 inland
late in the period. Nighttime lows will similarly be mild, and the
deviations from climo will tend to mirror the degree of cloud cover.
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
As of 12Z...Overnight shower/t-storm activity has dissipated.
Surface low pressure located about 60 miles NE of ILM will move
out to sea today, dragging a cold front southward across the
area. North-northeasterly winds developing behind this front
will gust to 22-25 kt most of the day as colder air surges
southward. Residual low clouds near the front will create the
potential of MVFR/IFR ceilings now through 14-16Z along the
coast. Upstream observations suggest ILM stands a better
potential of seeing IFR conditions than the CRE or MYR
airports. After 16Z drier air should dissipate any residual low
NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Wednesday...A wave of low pressure exiting the North
Carolina coast this morning will allow a cold front to move
southward across the waters beginning around sunrise. Behind this
front, northeast winds will accelerate to 20-25 kt with a few gusts
approaching 30 kt possible. The Small Craft Advisory has been
advanced to begin at 7 AM when the surge of stronger winds may begin
north of Cape Fear. Canadian high pressure up over the Great Lakes
will maintain these breezy northeast winds through tonight and
beyond. Seas currently only 2-4 feet will build to as high as 6-7
feet across open waters by this evening, maintaining that height
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 300 AM Wednesday...The Canadian high will be situated across
the Mid-Atlantic region Thursday morning and should move off the
Virginia and Maryland coast Friday. As often occurs, a westward
extension of this high will extend back across North Carolina. This
will weaken our pressure gradient and keep wind directions from
veering southeasterly as quickly as one might think. Small Craft
Advisory conditions will probably persist into Thursday afternoon
before diminishing Thursday evening.
LONG TERM /SATURDAY THROUGH SUNDAY/...
As of 300 AM Wednesday...The above normal temperatures will give a
clue as to expected marine conditions. That is, the area will be in
a return flow regime around sprawling Atlantic high pressure. Wind
will thus be southerly and for the most part be capped at 10 kt
though a few higher gusts certainly hard to rule out. A minor
increase in the long shore swell energy could make for an increased
presence of 4 ft seas along the outer portions later Sunday in an
otherwise 2 to 3 ft wave environment.
NC...Freeze Watch from late tonight through Thursday morning for
MARINE...Small Craft Advisory until 5 PM EDT Thursday for AMZ250-252-