Area Forecast Discussion
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FXUS62 KILM 251129
Area Forecast Discussion
National Weather Service Wilmington NC
729 AM EDT WED MAY 25 2016
Summer like warmth will continue through the end of the week as
high pressure remains entrenched across the western Atlantic. Low
pressure will develop near the Bahamas and move towards the
southeast coast this weekend. This feature will drift near the
coast Sunday through early next week bringing an extended period
of unsettled weather and cooler temperatures.
.NEAR TERM /THROUGH TONIGHT/...
As of 621 AM Wednesday...If you were a time-traveling, blindfolded
climatologist, stepping outside locally this afternoon and asked
what time of the year it is, you might guess in the heart of June
or very early July. The only subtlety or clue in this assessment
otherwise would be that dewpoints are not all that stifling as
yet. Maximums today 86-90 inland and 81-85 closer to the coast. A
strengthening sea breeze this afternoon will generate a rope of
inland progressing, enhanced surface convergence. While this may
spark moderate cumulus, overwhelming dryness above 8000 FT will
make it difficult to pop a shower, so no mentionables in the
precipitation category today. A fair evening and overnight period
expected with mostly clear skies and light surface wind. Patchy
ground fog is probable in some spots but increasing boundary layer
winds late will likely prevent extensive fog or mist coverage.
Minimums daybreak Thursday 62-68, and mildest near the Atlantic.
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 3 AM Wednesday...Main weather captions this time period
highlight above normal warmth Thursday similar to today, then a
chance of tropical showers late Friday night into early Saturday.
Confidence is high on a sunny and warm day Thursday, but a bit
less resolute on tropical moisture infusion timing late Friday.
At a minimum we will see an uptick in absolute low-level humidity
along with an increasing chance of moderately strong rip currents
and showers heading into the weekend. Increasing clouds will
shave a few Fahrenheits off our maximum temperatures on Friday
but the trade off of more humidity may keep apparent temps similar.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 300 AM Wednesday...All eyes for the Memorial Day weekend will
be on the tropics as a disturbed area of weather near the Bahamas
organizes into a wave of low pressure and moves westward towards the
southeast coast. Guidance has been remarkably consistent for several
days now in developing this system and drifting it westward...but
forecast confidence remains low as to how exactly our area weather
will be impacted.
Ridge of high pressure across the Atlantic Ocean will weaken and
move northward as the trough of low pressure skirts to the west
beneath it. By Saturday...at least a weak low pressure trough is
progged to be off the SC coast. This will then meander slowly in a
col on the western side of the weakening ridge...and it is primarily
the position and strength of that feature which will dictate the
movement of the trough. NHC has a 30% chance of subtropical/tropical
formation in the next 5 days...and while the low will move quite
slowly...water temps are cool and forecast models struggle to give
it a warm core.
That being said...it may be irrelevant as far as sensible weather
goes whether this becomes a named system or just a weak low
pressure...as an extended period of unsettled weather lasting
through the holiday weekend. Deep ribbon of tropical moisture could
angle directly into the ILM CWA...especially if the low stays to our
south...and some of the latest guidance has the low drifting SW
Sunday and then back to the NE early next week (similar to the track
of Beryl in 2012)...which could make for a long duration of
unsettled weather. Attm will show an extended period of CHC pop
throughout the period...but it is unlikely the entire 4 days will be
a washout as periods of rainfall will be dictated by upper
diffluence within jet structures...surface convergence...and
vorticity dynamics...all of which can vary highly.
Still...widespread clouds and at least periods of rain are forecast
Sat-Tue...with highs likely below climo and mins slightly above.
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 12Z...VFR with clear skies and calm winds this morning.
KILM VAD wind profile shows WSW-W winds around 15 kts above the
surface. These winds should translate to the surface around 6 kt
by the next hour and persist through much of the morning.
Good warming today should allow for a good sea/land temperature
contrast to develop. This should result in a S-SSW sea breeze
mid-late morning at KMYR/KCRE and by early afternoon at KILM.
Inland terminals should see winds back to light SW in the
afternoon. A relatively dry airmass will yield little cumulus
formation today. Winds should decrease around sunset and remain
Extended Outlook...Predominantly VFR conditions expected...until
the weekend when MVFR cigs are possible in scattered to numerous
showers, isolated TSTMS.
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-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 621 AM Wednesday...Smooth sailing and power boating
conditions on tap today as seas hold in a 1.5 - 2.5 foot range
today in 8-9 second intervals, co-mingled with a light SW chop.
Chop will build a bit in the afternoon as we expect a robust sea
breeze circulation and a few inshore gusts of S-SSW up to 18 kt
between 2 PM - 6 PM. No showers or TSTMS or restrictions to VSBY
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 3 AM Wednesday...Manageable marine conditions will prevail
Thursday with 2-3 ft seas, moderate S-SW winds and no hazardous
marine weather. Dominant wave periods Thursday 7-8 seconds so no
sharp wave steepness to contend with. Friday a good beginning but
development of an increasing fetch distance and speed will likely
boost sea heights to a 3-5 ft range late Friday. Very early on
Saturday a small craft advisory for seas cannot be ruled out as
the wave building fetch endures. Showers and isolated TSTMS will
be on the increase late Friday as potentially a tropical low
approaches the coast. If you have boating plans this weekend
please keep abreast of the trends from Friday into Saturday.
LONG TERM /SATURDAY THROUGH SUNDAY/...
As of 300 AM Wednesday...Significant uncertainty exists in this
period...but poor marine conditions are becoming more likely as a
wave of low pressure moves out of the Bahamas and towards the
southeast coast. The guidance is in agreement that this will
occur...but differ considerably on location and intensity and
timing. This suggests that while seas will almost certainly
increase on prolonged easterly fetch...up to at least 3-5 ft with
possible 6 footers both days...winds could be highly variable.
For now...have used a blend of the guidance to produce primarily
easterly winds at 10-15 kts...which will create a low amplitude
wind wave on top of the more significant easterly swell.
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