Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 232339
Area Forecast Discussion
National Weather Service Wilmington NC
739 PM EDT MON MAY 23 2016
An upper low will move slowly away from the Carolinas tonight with
a few showers and storms possible through nightfall. High pressure
will build across the region on Tuesday...and then move offshore
as a Bermuda high through the end of the week. This will bring
above normal temperatures with ample sunshine through Friday. More
unsettled weather is possible this coming weekend as a trough
approaches the coast from the Bahamas.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 630 pm Monday...Will remove POPs by mid-evening. Waning
insolation and resulting instability will be the demise of any
additional convective development quickly after sunset. This
trend already illustrated by a mosaic of 88ds across the
Carolinas. The diurnal cu field will also dissipate, leaving
a mostly clear or partly cloudy worse case from any altocu clouds
as displayed by various model rh time heights for locations across
the FA. See no need to tweak overnight temps at this time.
As of 330 PM Monday...Widespread field of stratocu covering most
of forecast area producing mostly cloudy skies...with only a few
breaks of sunshine. Water vapor imagery still showing upper low
digging down across NC with clouds and showers wrapping down
around the back end toward the area. With such cool 500 mb temps
down close to -25c this morning...the steep lapse rates helped
with rapid cu development by late this morning. The clouds have
slowed the rise in temps...basically reaching the mid 60s to
around 70 most places.
The southern extent of heavier showers was just north of local
forecast area wrapping around the deep NW flow. Expect showers to
be scattered mainly along northern portion of forecast area. Do
not expect much coverage overall with best lift closer to the
coast and farther north toward best energy wrapping around the
upper low. The temps aloft will actually begin to warm through
this evening with model soundings showing a spike right around
h70 making it bit harder to get any deep convection. Another
limiting factor will be the dry air and dewpoint temps right
around 50. Will most likely need to tap into some higher dewpoint
air from sea breeze front which will be almost non-existent due
to off shore flow and cool air temps which were running close to
the sea temps. The cool air aloft and low WBZ height will allow
for any deeper shwrs/tstms to produce some small hail. SPC
continues to show general thunder but has shrunken the area down
to include only NC and north into mid atlantic states. As of 3 pm,
lightning was limited from VA northward.
Look for convection to build over NC and drop into our area from
the N-NW and some localized development over SE NC and NE SC
between 17z and 00z before a diminishing trend. Expect clearing
with cool air in place for tonight leading to overnight lows in
the 50s once again except along the coast.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 330 PM Monday...A quiet mid week period with drying and
warming trend as pesky upper low lifts off to the northeast and
ridge builds in. Overall high pressure begins to dominate with
center in the off shore waters of the southeast, north of
bahamas. The light southerly return flow combined with rising h5
heights will allow for temps to soar into the 80s with plenty of
May sunshine both days. Tuesday should see close to 30 degree
temp rises after a cool start. By Wednesday, some locations may
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 330 PM Saturday...Very warm summertime conditions forecast
for the end of the week and the weekend as Bermuda high spins
offshore and mid-level ridging blossoms from the Gulf
Coast...moves overhead...and expands across the southeast. This is
a pattern that suggests above normal temperatures...but also
increasing humidity on the SW return surface flow. However...the
ridging aloft will keep the mid-level dry thanks to
subsidence...so diurnal convection will be isolated at best...and
other than Thursday thanks to a weak impulse moving overhead...the
Thu-Sat timeframe will be dry with temps approaching 90
inland...low/mid 80s closer to the coast.
Uncertainty increases for the weekend and into the Memorial Day
holiday. The surface and mid-level ridge drift north as a weakness
develops beneath it. Within this weakness a trough of low pressure
is progged to move out of the Bahamas and drift slowly towards the
southeast coast. The GFS has been incredibly consistent with this
feature...despite large fluctuations in its position and
intensity...while the ECM/CMC...which have been showing a weak
trough...have jumped on board with a more significant system with
the 12z suite today as well. GFS Ensembles are almost entirely in
agreement with the op-run also. While it is far too early to mention
any actual low pressure affecting the area...there is increasing
confidence that deepening easterly flow connected to the tropics
will create more unsettled weather this weekend and into Monday.
Have trimmed highs a bit for Sun/Mon while also ramping up precip
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --As of 00Z...Showers resulting from instability induced by dayime
heating and the cool pool associated with the upper level low over
the region are winding down as the sun sets. Outside of a little
MVFR fog, mainly at inland terminals, conditions should
be VFR through the valid TAF period. Light north to northwest
winds tonight will become southwest at 5 to 10 KT during the day
Extended Outlook...Predominantly VFR conditions expected.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 645 pm Monday...Looking at mainly offshore winds tonight.
The sfc pg will remain relatively relaxed, yielding around 10 kt.
Except 10 to 15 kt north of Cape Fear due to the effects from the
departing upper low. Significant seas will run around 2
ft...except 2 to 3 ft from Cape Fear northward. Wind driven waves
will remain a low input to the overall significant seas.
Basically, a 1 to occasional 2 foot ese ground swell at 8 to 9
second periods will provide the sig. seas input.
As of 330 PM Monday...Northwest, offshore flow and very weak sea
breeze, if any, will produce fairly glassy seas in the near shore
waters through tonight. The water temps were running near the air
temps this aftn and therefore do not expect any chop. The only
gusts you may experience would come from an isolated passing
Winds will begin to slowly shift around from NW to W overnight
but will remain very light as high pressure begins to take hold.
Overall expect benign seas under 3 ft.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 330 PM Monday...Quiet marine conditions expected through
mid week as high pressure takes residence over the off shore
waters off the southeast coast. Overall expect a light southerly
return flow to set up. Near shore seas will experience some chop
in the afternoons due to a strong sea breeze setting up as temps
warm well into the 80s...more typical May conditions. Seas will
generally be 3 ft or less.
LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 330 PM Monday...S winds around Bermuda high pressure will
be predominant Thu/Fri before winds back more to the E/SE late in
the period. Gradient around the offshore high remains weak...so
winds Thu/Fri will be 10 kts or less...and the combination of
these light winds and a 2ft/8sec SE swell will drive wave heights
of 1-2 ft Thu...2-3 ft Friday. Late Friday and Saturday confidence
decreases as a wave of low pressure may emerge from the Bahamas
and approach the waters. This will drive increasing easterly winds
and wave heights building to 3-4 ft...possibly higher if a longer
period swell develops.