Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
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FXUS62 KILM 231733
Area Forecast Discussion
National Weather Service Wilmington NC
133 PM EDT MON MAY 23 2016
An upper low will move across the eastern Carolinas today with
scattered showers and thunderstorms possible through the evening.
The low will move offshore Tuesday as high pressure builds over
the region. Drier weather combined with above normal temperatures
will follow mid week into next weekend as an upper ridge expands
from the Gulf states.
.NEAR TERM /THROUGH TONIGHT/...
As of 11 AM Monday...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...still in the mid 60s over NC late this
morning and close to 70 over most of NE SC. Expect showers to be
scattered mainly across NC earlier in the aftn but then focused
mainly along sea breeze convergence from the tip of Cape Fear down
to Georgetown. 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 this
aftn and model soundings show some warming right around h70 making
it bit harder to get any deep convection. Another limiting factor
will be the dry air with dewpoint temps right around 50 will most
likely need to tap into some higher dewpoint air from sea breeze
front. The NW flow should keep the sea breeze from penetrating
too far inland. The cool air aloft and low WBZ height will allow
for any deeper shwrs/tstms to develop hail.
Overall expect Scattered showers and isolated
thunderstorms accompanied by hail expected this afternoon...as an
impulse discernible in vapor animations over central Virginia
snared in the cold pool circulation aloft drops S-SE across SE NC
and very NE SC. SPC maintains only `general` thunder status here
today since any strong to severe convection will remain isolated
in scope and farther north...yet non-zero in any one locality.
Interestingly...although less coverage is expected over NE SC
compared to SE NC this afternoon...the stronger insolation could
result in more robust towers over NE SC...so no one is entirely
out of the `hail woods`. Look for convection to build over NC and
drop across and develop over SE NC and NE SC between 17z and 00z
before a diminishing trend.
Expect clearing and cool air in place for tonight leading to
overnight lows in the 50s once again except along the coast.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 3 AM Monday...Drying and warming trends the primary caption
this period as the upper circulating chilled pool lifts NNE away
from the area and loosens its hold. Subsequent height rises and
thickness surges will bring above normal temperatures by
Wednesday...with some locations nearing or reaching 90...middle
and upper 80s closer to the coast as the sea breeze circulation
fully awakens. The coolest portion of this period daybreak Tuesday
with readings entrenched well into the cooling 50s.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 3 AM Monday...Surface and mid level ridging in place through
the period will work to keep the region mostly rain free. Mid level
moisture emanating from southern TX mid-week will move across the
top of the ridge and over the east coast. The increased moisture
aloft combined with low level return flow around west side of
Bermuda High may allow for some isolated diurnal convection Thu and
Fri. Mid level ridge builds up the east coast Sat and Sun decreasing
moisture aloft but low level southeast flow will lead to increasing
boundary layer moisture. So while cloud cover may be on the increase
Sat and Sun precip chances may be limited by the dry air aloft.
Temperatures will run above climo through the period.
There is one potential fly in the ointment Sun. The GFS has
continued to show a weak area of low pressure emerging from the
Bahamas late in the week. The has been very little consistency with
the location, timing, or strength of the low but it has been
consistently present. Currently the CMC and ECMWF do not depict this
feature and for now the low is being discounted. It is worth noting
that the GFS sends a slug of tropical moisture into the Carolinas
late in the weekend with an increase in cloud cover and precip
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --As of 18Z...The upper level low is still impacting the area with
scattered to broken ceilings this afternoon. Expect a few showers
as well but not enough coverage to warrant in tafs. Overall still
expect vfr conditions through the period with clearing skies
tonight. I did add a little mvfr fog for inland sites as winds
will back off and guidance shows dewpoint depressions near zero
for a few hours.
Extended Outlook...Predominantly VFR conditions expected.
-- End Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
As of 11 AM Monday...Offshore flow today will keep seas behaved
but highest outer portion...while very manageable marine
conditions prevail inshore. Showers and a few TSTMS will move off
land and across the waters in the afternoon to early evening and
hail may fall in the stronger convection. Sea spectrum comprised
of SE wave 2-3 FT every 9-10 seconds and a light to moderate N-NW
chop highest outer waters. Any storms will move from NW to SE and
could produce gusts in excess of 35 kt. Wind-speeds will ease
overnight as a surface low offshore of the outer banks jogs N and
weakens. Overall wave heights 2-4 feet...highest outer ribbon.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 3 AM Monday...The main marine headline this period is a
resumption back to normal marine winds typical of late May...SW
10-20 kt and seas essentially 2-3 feet. Shower and storm coverage
will have ended for the 0-20 NM waters by Tuesday and holding
through Wednesday. Dominant wave period of around 9 seconds are
expected, so wave steepness will remain low aside from light and
occasionally moderate S-SSW chop as the afternoon sea breeze
LONG TERM /THURSDAY THROUGH FRIDAY/...
As of 3 AM Monday...Bermuda High will be the dominant feature
through the period with south to southwest flow across the waters.
Gradient will keep speeds on the low end of the 10 to 15 kt range
with the only exception being the increase in speeds along the
coast due to the afternoon sea breeze. Seas will remain around 2