Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
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FXUS62 KILM 010540
Area Forecast Discussion
National Weather Service Wilmington NC
1240 AM EST Wed Mar 1 2017
The area will grow increasingly warm ahead of a strong cold
front Wednesday night. Seasonably cool temperatures will follow
late week, with temperatures possibly falling below freezing
Saturday morning. A warming trend is expected Sunday through
early next week.
.NEAR TERM /THROUGH TODAY/...
As of 900 PM Tuesday...Winds were strong just above the boundary
layer this eve, up to 30 to 40 kt. These strong SW winds will
persist and this will keep winds elevated which will preclude
the development of widespread significant fog. Across the
cooler shelf waters, mixing should be less effective. We expect
widespread low stratus to develop overnight. The risk for
significant sea fog will increase during the late night hours.
The marine stratus may have a tendency to lower, although water
temps are not as cool as they normally are for the beginning of
March. We have added some fog to portions of the coast
overnight. A few marine showers may come close to the beaches,
but we are keeping it dry overnight as some very light shower
activity to our N moves E, but stays just to the N of the FA.
Previous lows were raised a degree or two given the high
dewpoints, thickening clouds and elevated winds. Lows should be
mainly in the mid 60s.
Increasingly strong warm advection in advance of the next cold
front will lead to impressively warm temperatures on Wednesday,
with lower to mid 80s most places and 70s at the beaches. A spot
shower is possible during the day, but a more substantial shower
and thunderstorm risk will hold off til Wednesday night.
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...A cold front with fairly strong wind fields
will be entering the area Wednesday night. SPC has outlined a
Marginal Risk area-wide. Given that WRF/GFS show roughly 300-600
J/Kg of MLCAPE especially over western zones this seems
plausible. Wind damage will be the main severe weather form with
a shallow EML above the surface inversion and some mid level
dry air lingering into at least the first part of the overnight.
Similarly 850mb winds may ramp up to 50kt. This boundary and
its associated moisture push offshore very quickly Thursday
morning allowing for some pretty robust cold advection, possibly
even leading to a non-diurnal temperature curve. This cold
advection shuts off Thursday night but not before cooling the
airmass sufficiently to bring seasonably cool low temperatures.
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 325 AM Tuesday...Main theme this period is seasonably
cold, and below normal temperatures on Saturday, where sub
freezing readings may prevail at daybreak Saturday as strong
high pressure migrates across the region. The cold early
Saturday could damage early blooms or flowering crops. The high
will slip off the SE coast Sunday allowing the start of a
warming trend. Late Monday a cold front will approach from the
west, but with the parent low over the Great Lakes, the front
may not be very powerful here locally.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 06Z...Complex forecast the next 24 hours with fog,
stratus, strong winds, and thunderstorms all expected.
High pressure offshore will continue to be the dominant feature
through the valid period, but the gradient will become increasingly
pinched ahead of a strong cold front which will move into the area
late Wednesday night. As this occurs, SW winds will steadily
increase, becoming around 10 kts tonight, and then rising to 15-20
kts with gusts up to 30 kts after sunrise, and persisting through
the end of this valid period. These strong winds will mostly
preclude fog overnight, the exception being at CRE/MYR where sea fog
may impact the terminals at times through Wed morning, but stratus
will likely become widespread and lower to IFR/LIFR overnight. This
stratus will break a few hours after sunrise with VFR expected
during the aftn before the cold front approaches late. Thunderstorms
are expected along this front, and have added VCTS to all terminals
late, but most of the impacts from convection are expected just
after 06z Thursday.
Extended Outlook...Reduced ceilings and visibility and strong
winds in heavy showers and strong thunderstorms into Thursday
morning, otherwise VFR.
-- End Changed Discussion --
NEAR TERM /THROUGH WEDNESDAY/...
As of 900 PM Tuesday...Conditions are favorable for sea stratus
overnight into Wed. However, the concern is whether the status
will lower to the sea surface. Water temps are in the lower 60s
and this is above normal for the beginning of March. Thus, with
strong winds aloft, there may be slightly better mixing of
these winds to the surface then we would normally expect for
this time of year. We have added fog, but kept any visibility
restriction above 1 mile and so a Dense Fog Advisory has not
been issued for the waters at this time.
The wind direction overnight will be from the SW at speeds of 10
to 15 kt. Seas will remain near 3 ft.
Winds on Wednesday will increase ahead of a strong cold front.
We are forecasting sustained SW winds of 15 to 25 kt with higher
gusts. This will result in seas building through the day. A
Small Craft Advisory is likely for late Wed and Wed night as
wind speeds increase to 20 to 30 kt and seas build to 4 to 7 ft.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM Tuesday...Prefrontal SW flow regime may strengthen
to the point where Small Craft Advisory is needed even if seas
fall a little short. A few Advisory-worthy 6 ft seas may join
the advisory- worthy winds Wednesday night however as the
boundary nears. A sharp veer to NW will occur Thursday during
the pre-dawn hours, likely steepening wave faces. Even though
seas may be rather choppy then Thursday the overall dominant
wave height will diminish along with the winds and all flags
will advisory flags will drop. Both will continue to abate
Thursday night as high pressure builds in behind the boundary.
LONG TERM /FRIDAY AND SATURDAY/...
As of 325 AM Tuesday...Clipper like system will bring an
increase in N winds Friday but improvement is expected into
Saturday as high pressure moves almost overhead, but chilly.
Seas Friday 3-5 feet will ease to 2-4 feet into Saturday. An
under-lying ESE swell of 1-2 feet will prevail this period.