Area Forecast Discussion
Issued by NWS Wilmington, NC

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FXUS62 KILM 240452

Area Forecast Discussion
National Weather Service Wilmington NC
1152 PM EST Thu Feb 23 2017

Warm air will prevail across the Carolinas through Saturday.
A cold front approaching from the west will move offshore late
Saturday. Cooler and drier air will build in Saturday night
through Monday. Shower chances will increase mid week as a cold
front approaches from the west.


As of 1155 PM Thursday...Removed all mention of precipitation
overnight as the showers well offshore will not be able to make
survive west of the warm Gulf Stream waters. Also added areas of
fog to all but the immediate coast overnight as a moist, cool,
and nearly calm boundary layer should begin to fog up over the
next few hours. No other significant changes have been made to
the forecast. -TRA    Discussion from 1045 PM follows...

Have indicated the low chance, below 20 percent, POPs for
mainly along the immediate coast from Cape Fear northward.
Latest sat imagery shows cu/sc moving onshore. Latest KLTX 88D
indicates just enough DB`s shown in conjunction with the onshore
movement of the low level clouds for pcpn to occur. Will
continue this low pcpn threat thru the night. QPF, a couple one
hundredths of an inch possible. Overnight lows will remain
unchanged however, hourly sfc temps and dewpoints will need
updating based on latest trends along with hourly RH and
apparent temps. However you look at it, another mild night in
store for the bi-state region. The back edge of the mid and
upper level clouds extended from Elizabethtown to Georgetown.
Not much movement in any direction this evening, other than the
clouds themselves. But do expect the back edge to progress to
the immediate coast by sunrise Fri and further eastward during
daytime Fri.


As of 230 PM Thursday...Morning clouds will break Friday and in
tandem with an upper ridge axis over the region, near record
temperatures may be reached or exceeded. Record highs for
tomorrow include CRE-78 in 1996, ILM-81 in 1982, FLO-82 in 1962,
LBT-77 in 2016. Afternoon heat-induced cumulus expected Friday.
Another warm one Saturday in a pre-frontal sector and breezier.
Maximums may be similar to Friday, to a few degrees cooler near
the coast and well inland. The moisture profiles are quite dry
Saturday and an isolated shower may even be too hopeful with
FROPA in the mid afternoon to very early evening west to east.
Mammoth temperature differences from Saturday afternoon to
Sunday morning, drops of 35-40 degrees.


As of 230 PM Thursday...Cold advection weakens on Sun but
the colder air will be in place and temperatures will drop near
to slightly below climo, despite plenty of sun and deep
westerly flow aloft. Surface high moves off the coast later in
the day with return flow developing then increasing for Mon as
5h trough to the west starts to amplify. Southern stream
shortwave will emerge from the southwest this weekend but its
evolution remains the subject of much debate between the medium
range guidance. It appears likely that the wave will be
deamplifying as it heads east, lifting northwest of the area Mon
night. The associated surface low will drag a boundary into the
region but lack of strong mid level trough/push leaves the
surface boundary hanging. Latest GFS has it stalled in the area
with a period of unsettled weather Mon night through Wed night
(albeit with temps above to well above climo). The ECMWF depicts
a stronger 5h ridge over the southern Gulf of Mexico which
expands north Wed leading to a slightly warmer and drier
forecast compared to the GFS.

Wed night into Thu medium range guidance converges on a cold front
pushing across the area, pushed east by longwave 5h trough. Front
would be accompanied by showers and likely some thunder with cold
advection following the front dropping temps back near climo as the
period ends. Confidence for much of the period is low due in large
part to the problems guidance tends to have with split flow.


As of 06Z...HRRR keeps isolated showers away from the coastal
terminals this morning with weak coastal trough off the se coast.
concern will be for local IFR conditions in FG between 09-13z this
morning. Latest satellite loop showing mainly cirrus shield from low
to our se moving to the ne with the coastal sites on the fringe of
these high clouds. Inland terminals have cleared but could see some
stratus develop with FG. Otherwise VFR through the remainder of the
evening as well as soon after sunrise friday.

Extended Outlook...VFR.


As of 1155 PM Thursday...Added a solid foot to sea heights
overnight into Friday morning based on current observations from
NDBC and CORMP buoys near Cape Fear. Seas are already up to 8
feet at the Frying Pan Shoals buoy, indicative of the very
energetic southeasterly swell moving in. Showers should not make
it beyond 20 miles from shore, and have been removed from the
forecast as well. Discussion from 1045 PM follows...

SCA in effect for all waters, mainly due to seas reaching SCA
thresholds. Update concerned with the timing of the increasing
seas. Frying pan shoals 41013 buoy already having surpassed 7 ft
with inshore buoys at 3 to 5 ft. Overall, looking at 3 to 6 ft
for seas by daybreak Fri and holding steady thru Friday. Both
the upper and sfc lows respectively, were located over the
Bahamas this evening and are progged to lift northeast to a
location at approximately 300 miles southeast of Cape Fear by
daybreak Fri. The sfc pg will remain somewhat loose, with 10 to
15 kt resulting, and the sfc pressure pattern will yield NE wind
directions. Could see isolated light showers over the coastal
waters, mainly north of Little River Inlet.

As of 230 PM Thursday...Advisory for seas much of Friday
as a SE swell plays out. NE 5-15 knot winds to accompany the
formidable swell, will become light and variable Friday night.
As a front approaches Saturday SW winds 10-20 knots to prevail
before a shift to the NW-N Saturday evening. An advisory or
exercise caution statement is possible just before and then
after the frontal passage. Very little precipitation expected so
no restrictions to visibility expected Saturday or in the
night, but the winds may be challenging and chop will run
moderate to strong.

As of 230 PM Thursday...Offshore flow will weaken Sun as cold
advection shuts off and gradient weakens due to approach of the
center of the surface high. Northerly flow becomes light and
variable Sun night, becoming southerly Mon morning as the high
pushes off the coast. South to southwest flow increases to 10 to
15 kt Mon into Tue as gradient becomes a little more defined.
Seas 2 to 4 ft Sun drop to 2 to 3 ft Sun night and Mon before
the slight increase in southwest flow later Mon and Tue pushes
seas back up to 2 to 4 ft.


MARINE...Small Craft Advisory until 7 PM EST Friday for AMZ254-256.
     Small Craft Advisory until 7 AM EST Saturday for AMZ250-252.


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