Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 271727
Area Forecast Discussion
National Weather Service Wilmington NC
127 PM EDT SAT AUG 27 2016
Warm late summer conditions will prevail through the weekend. The
chance of showers will increase as well, as moisture from the
tropics moves across the area early next week. A strong cold
front is expected to move across the region late this week.
.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Saturday...No changes to the ongoing forecast as
mainly clear skies continue over the forecast area. The former
circulation of Fiona south of Bermuda contained winds near 35 mph
east of the center per aircraft measurement last night, so it will
be interesting to see what transpires today as this feature moves
west toward the Carolinas taking in the dry air aloft. The
previous forecast discussion follows.
A gleaming start to Saturday shaping up with a clear early
morning view of a waning crescent moonrise, signaling clear skies
to the east. A surface ridge axis positioned SW to NE across the
area was resulting in a relaxed pressure and wind regime. Vapor
movies shows an upper ridge north of the region with an embedded
impulse currently positioned across eastern VA and the Delmarva
coast. Vad Wind Profile this morning shows 30-40 KT mid- level NE
flow, which will usher deepening H7 moisture today. As this
impulse is driven SW today, a shower or TSTM may pop over Bladen
or Robeson county in the middle afternoon, spreading SW into the
SC interior in the late afternoon. Convection may linger tonight
along the I-95 corridor as a secondary upper wave transits the
interior overnight. Maximums above normal today, middle 90s over
the deeper interior and lower 90s across the coastal interior in a
light onshore wind. Min temps daybreak Sunday 71-74, 75-77 at the
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM Saturday...Primary headline this period is a
transition to a tropical influence as the circulation of former
Fiona drifts landward toward the Cape Fear region late in the
period Monday night into Tuesday. This feature will be watched
closely over the next few days. The other tropical item of note
remains arrival of long period swell from the Gaston wind-field on
Sunday. Wave amplitude will remain low, but could build to 2 ft
every 13-14 seconds Monday, prompting an significant rip current
risk. Pop values increase gradually through the period as the
tropical influence does so, especially late in the period as PWAT
values begin to notably rise.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 300 AM Saturday...Increasing tropical moisture across the
area along with persistent on shore flow will produce an increase
in shwrs/tstms through mid week. Looks like the combination of
moisture remnants from Fiona along with tropical wave/low reaching
up from the south, as well as, weakening ridge moving north away
from Carolinas will produce plenty of clouds and more widespread
shower activity especially along and just off the coast on Tues
into Wed. GFS shows greatest pcp water values up over 2 inches
located over area Tues night into Wed. By Thurs this moisture
should be pushed off to the east as mid to upper trough pushes a
cold front into the Carolinas. The winds will shift around to the
N-NW on back end of tropical wave/low which may help to advect in
some drier air but overall expect front to produce enhanced
convective activity, mainly farther south over South Carolina by
Summerlike temps in the mid 80s to 90 should take a dip heading
into end of period down into the mid 80s.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
As of 18Z...High confidence in VFR through tonight other than some
potential short duration vsby restrictions in tstms inland this
evening. Stratus is possible overnight.
A weak back door type cold front is slowly shifting southward this
aftn, and will weaken as it drops across the CWA tonight. This front
is the driver for some showers/tstms to the north, and as it pushes
southward a few of these are expected to approach the inland
terminals. Have included VCTS, but not enough confidence in coverage
or timing for a TEMPO or any restrictions attm. Coastal terminals
are expected to remain dry today. Winds through the evening will be
generally from the E/SE around 10 kts.
As the front pushes across the area tonight, winds will return to
the NE at around 5 kts, with subtle increase late in the overnight
possible. This will likely prevent much in the way of fog, but
soundings suggest stratus is possible, mostly likely at LBT, which
is more typical with a setup like this. Some fog is possible at FLO
where the front will be slow to drop through. Any stratus will lift
after daybreak Sunday with VFR returning under continued light NE
EXTENDED OUTLOOK...Increasing chance of TEMPO sub VFR each day as
tropical moisture/shower potential increases through Tuesday. VFR
NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Saturday...Latest obs show combined seas in the 4
ft range. The early morning update did raise seas by a foot to
cover this, so no further changes were needed with the mid-morning
update. Relevant portion of previous discussion follows:
Light winds and manageable seas prevail today and tonight. Seas
of 3-4 feet slightly elevated in ESE waves 2-3 ft every 11
seconds originating from circulation of former Fiona. This should
slowly decay to 9 seconds overnight. Light onshore winds today and
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 300 AM Saturday...Decent marine conditions will prevail
this period in terms of welcoming light winds, generally NE-E
Sunday and Monday. Increasing swell waves may elevate sea heights
to 4 ft Monday night, and an increase in showers and TSTMS can be
expected, as a tropical disturbance, and what was once Fiona,
approaches Cape Fear late Monday night. Mariners should monitor
the latest forecasts regarding this feature.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
As of 300 AM Saturday...Diminishing longer period E-SE swells, up
to 14 seconds, will mix in with E-NE wind waves through the
period. Overall expect winds in the 10 to 15 kt range and seas 2
to 4 ft.