Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 231716
Area Forecast Discussion
National Weather Service Wilmington NC
1212 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.
.NEAR TERM /THROUGH TONIGHT/...
As of 10 AM Thursday...Reduced cloud cover inland for the mid
morning updates, no other notable changes other than fine tuning
As of 3 AM Thursday...Powerful upper level low pressure is
centered over South Florida this morning. The surface reflection
of this low is quite strong given the low latitude it has
developed at: 1001 millibars between Orlando and Cape Canaveral.
Several new areas of low pressure are expected to develop off
the Florida east coast through tonight, pinwheeling westward
toward the upper system. All this mess should remain far enough
south to spare the Carolinas any significant effects.
Cyclonic flow around the Florida low is bringing subtropical air
onshore. Sprinkles and isolated light showers are evident on radar
moving northwestward around 15 mph. These showers should not become
any deeper or better organized through the morning as a strong
capping inversion between 6000-9000 feet AGL will continue.
Much like yesterday, the airmass remains rather warm for this time
of the year. 850 mb temps around +9C or +10C may not sound like
much, but should still allow highs to range from the upper 70s along
the I-95 corridor to around 70 on the beaches.
The back edge of the mid and upper level moisture should clear east
of the area early this afternoon, leaving mainly low-level cumulus.
Once evening arrives even this low-level cloud cover should
dissipate. Lighter winds may allow better radiational cooling to
develop with lows expected to fall into in the lower to middle 50s.
Areas of fog are also expected to develop given dewpoints expected
to run several degrees higher than forecast lows throughout today
and this evening.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 AM Thursday...The big Florida low will weaken Friday and
Friday night as it moves slowly northeastward, remaining well off
the South and North Carolina coast. An unseasonably warm airmass
will remain across the Carolinas, with high temperatures expected to
tag the 80 degree mark for many inland locations both Friday and
Saturday. Residual onshore flow on Friday should keep the immediate
coast considerably cooler.
Attention will then shift to low pressure in the Great Lakes on
Saturday. This low will push a cold front into the Carolinas and
offshore Saturday evening. Dynamics with this system shear out to
the north, leaving very little impetus for precipitation this far
south. The front is expected to come through dry. Breezy southwest
winds ahead of the front will turn northwesterly Saturday night with
much chillier and drier air advecting in.
Climate note: Both Florence and Lumberton have already hit 80 once
this month back on Feb 12th. If more 80s occur Friday and Saturday
that will make three times this month. The last time this occurred
in February in Florence was 2011. It was never occurred since the
Lumberton ASOS was installed in 1999.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 300 AM Thursday...A west to east zonal mid level pattern will
be in place part of the period which equates to fast moving and
relatively weak systems. The one constant, after a cool start
will be the resumption of the very mild condiitons. The pattern
becomes more southwesterly in time. At the surface relatively
cool high pressure will give way to a pronounced southerly flow
Monday through Wednesday with a slight chance of showers
associated with the warm front Tuesday. There will also be a
slightly higher chance of showers as the day progresses
Wednesday as another system moves in from the west. After a cool
start, although near climatology, Sunday and Monday morning,
expect highs to surge back into the 70s for the remaining
forecast days with very warm overnight lows in the 50s and maybe
in the 60s late.
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --As of 18Z...Low clouds in the process of scattering out as is the
coastal cirrus layer. High pressure ridge hangs on inland while
Florida system pushes ENE. In between the two some light onshore
flow will continue, trying to moisten the low layers. Late night
cloudiness will return but may have trouble being any more than FEW
to SCT. The extent of the cloud cover will modulate our fog
potential, which is not agreed upon terribly well between models.
Have introduced some IFR over inland zones where cloud cover may be
hard-pressed to materialize. Otherwise VFR through the evening as
well as soon after sunup tomorrow.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 10 Am Thursday...ESE-SSE wave energy moving ashore,
presently in mixed periods of 5-6 and around 8 seconds with a
moderate chop, a bit messy, and sea heights will continue to
grow to Advisory levels by tonight, 5 ft near Frying Pan
currently, 3-4 feet closer to shore. No significant changes
needed tot he forecast with the mid morning update.
As of 600 AM Thursday...Low pressure swirling across Florida
today will move northeastward tonight, remaining several hundred
miles southeast of the Carolina coastline. The large cyclonic
circulation surrounding this low will generate strong winds
between the Bahamas and Bermuda, resulting in increasing swells
this afternoon and tonight. The combination of wind wave and
swell should finally reach 6 feet as close as 10-20 miles from
shore tonight, triggering the issuance of a Small Craft Advisory
for all waters beginning at 7 PM this evening.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 AM Thursday...The big Atlantic low will slowly weaken
Friday and Friday night as it crawls northeastward, remaining well
off the South and North Carolina coast. A significant backswell from
this system will continue through at least Friday evening.
Attention will then shift to a cold front moving quickly eastward
across the eastern U.S. Anchored to low pressure in the Great
Lakes, this front should swing through the coastal Carolinas
Saturday evening, likely accompanied by a period of Small Craft
Advisory conditions for strong winds.
LONG TERM /SUNDAY THROUGH MONDAY/...
As of 300 AM Thursday...A rather brisk northwest flow will continue for
a few hours Sunday morning with speeds of 15-20 knots. The winds
will decrease dramatically later Sunday as high pressure moves
across the region. A return flow from the southeast will commence
Monday with speeds on the lower end of a 10-15 knot range.
Significant seas will also be on the high side for several hours
Sunday with at least 3-5 feet but will subside to 1-3 feet
MARINE...Small Craft Advisory from 7 PM this evening to 7 PM EST Friday
Small Craft Advisory from 7 PM this evening to 7 AM EST
Saturday for AMZ250-252.