FXUS62 KILM 211514

Area Forecast Discussion
National Weather Service Wilmington NC
1014 AM EST Wed Feb 21 2018

Temperatures will remain well above normal, even into the
weekend, as strong high pressure holds offshore. A cold
front will approach the coast this weekend, and stall over,
or just south of the area early next week, bringing a chance
of rain. High pressure will build from the north through the
middle of next week, keeping temperatures closer to normal.


As of 1014 AM Wednesday...Able to axe the DFA a tad early, and
now the stage is set for a sunny and warm day today, with near
record warmth on tap. Diurnal cumulus will become abundant, but
along the immediate coast is where the most sunshine minutes
may rack up, barring prolonged bouts of landward marching sea
fog. Have rebuilt sky cover grids to indicates less coastal
clouds, as the strengthening sea breeze creates a zone of
subsident air near shore, conversely, as a zone of convergence
advance inland this afternoon. Since the synoptic wind and sea
breeze motion trajectory are nearly aligned, the convergent zone
should make progress well inland this afternoon. A few light
showers with surface heating may spring up in this convergence
inland later today, but sure to be low-topped, brief, non-
extensive, and a challenge to get measurable rain.

As of 4 AM Wednesday...Temps will once again, reach near or
record breaking highs this afternoon as ridge aloft and plenty
of WAA produce readings up near 80 most places away from the
beaches. The 850 temps will remain right around 14 to 15C
through the period. Expect another night of decent radiational
fog with patchy dense fog once again. Temps will drop to within
a couple of degrees of 60 most places, which is more
representative of max temps this time of year. Records for today
2/21 include, ILM 78 in 2014, FLO 81 in 1997, and CRE 76 in


As of 400 AM Wednesday...The Forecast Area will remain under
the influence of a strong, but slowly weakening Western Atlantic
Ridge. The ridge will slowly shift S as we progress from Thu
into Fri. A backdoor cold front is expected to stall N of the
area Fri before moving back to the north.

Subsidence should continue to largely suppress convection, but
moisture does grow a little deeper which should allow for
greater vertical depth to the cumulus field. Low level moisture
remains high and guidance continues to support fog/low stratus
development, especially during the late night and early morning
hours. Will include patchy fog in the gridded forecast at this
time, although at least some of this fog will likely become
dense. The theme remains the same regarding sea fog as well.
Dewpoints remain marginally favorable while the prevailing wind
direction veers slightly to become a little more favorable as
compared to recent days. Will portray patchy fog lingering at
the beaches longest each morning and developing soonest during
the late eve.

Highs will be around 80 each afternoon with a sharp temp gradient
near the coast due to marine influences. Highs at the beaches
will be about 10 degrees cooler. Lows will be in the upper 50s
and lower 60s.

Record highs should continue to be challenged or broken...

City               High Temperature Forecast/Daily Record High

Wilmington         79/78 in 2003

Florence           82/80 in 1990

N Myrtle Beach     74/75 in 2007

Lumberton          81/78 in 2003

City               High Temperature Forecast/Daily Record High

Wilmington         78/80 in 1975

Florence           81/83 in 1975

N Myrtle Beach     75/74 in 2017

Lumberton          80/78 in 1971


As of 300 PM Tuesday...An exceptional upper level ridge will
remain anchored off the East Coast through this weekend. Model
consensus 500 mb heights peak on Wednesday at 593 dam along the
coast, nearly 3 standard deviations above normal, and among the
highest values ever measured this early in the year. Nestled
beneath this upper ridge will be the Bermuda high at the
surface. This summerlike feature will maintain a south-
southwesterly wind across the Carolinas and with very warm
conditions continuing.

Record high temperatures could occur on Sunday ahead of a cold
front, with highs all weekend ranging from the upper 70s to
lower 80s away from the cooler beaches.

A strong subsidence inversion Saturday should keep the area dry
despite what should be plenty of cumulus around. By Sunday an
upper trough shearing northward as it moves into the ridge may
punch a large enough hole in the inversion to allow some deeper
convection to develop. As the cold front moves through the area
early Monday, the GFS and Canadian models suggest more showers
could develop in a brief period of overrunning behind the front,
however the ECMWF is dry. All models show the front should be
far enough south by Tuesday for drier weather to develop with
temperatures falling much closer to normal.


As of 12Z...Repetitive pattern continues with morning dense fog
followed by unseasonably warm afternoon. A summer like high pressure
resides offshore with southerly flow and subsidence. A few showers
are possible west of our CWA otherwise just scattered cumulus.
Tonight, another warm night with fog likely.

Extended Outlook...VFR. Morning IFR/BR possible through Thur am.
Sea fog possible through Thu but confidence is low.


As of 1014 AM Wednesday...Fog still plaguing the inshore waters
and will hold onto marine `dense fog advisory` at least until
noon. Extending the marine fog advisory is possible, Dominant
wave periods will hold around 7 seconds, from the SE at 3 ft, up
to 4 ft outer waters. No TSTMS in the near term, but a few
light showers can be expected from time to time. The primary
hazard remains low visibility in patchy dense sea fog.

As of 600 AM Wednesday...Light southerly flow around Bermuda
High will persist through tonight. Expect winds to remain 10 kts
or less except a spike in winds in the afternoon due to sea
breeze. Expect seas to hold around 2 to 3 ft most waters with a
slight increase in SE swell through the period. This very warm
and moist air over the cool shelf waters will produce sea fog
which will be dense at times.

As of 300 AM Wednesday...The coastal waters will remain under
the influence of a strong, but slowly weakening Western Atlantic
Ridge. The ridge will slowly shift S as we progress from Thu
into Fri. A backdoor cold front is expected to stall N of the
area Fri before moving back to the north.

The biggest hazard to mariners will be sea fog. We have included
patchy fog in the gridded forecast through the period. Sea
surface temps will be in the mid to perhaps upper 50s. Dewpoints,
while unseasonably high for late Feb, will only be marginally
conducive for sea fog development. However, the wind direction
will veer slightly which will allow for slightly better residence
times over the cool shelf waters.

Benign wind and sea conditions will persist. The wind direction
will be S to SW at 10 kt or less although wind speeds may
briefly reach 10 to 15 kt across the near shore waters due to
the afternoon seabreeze circulation. Seas will be 2 to 4 ft.

As of 300 PM Tuesday...High pressure will remain anchored off
the East Coast between Cape Fear and Bermuda through the
weekend. This should maintain a south-southwesterly wind
direction through the period.

As a cold front crosses the southern Appalachians Sunday, our
pressure gradient will tighten substantially. Relatively gentle
winds Saturday should increase to around 20 knots on Sunday
with seas building to a very choppy 5-6 feet.


MARINE...Dense Fog Advisory until noon EST today for AMZ250-252-254-256.




NWS ILM Office Area Forecast Discussion