Area Forecast Discussion
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FXUS62 KILM 221034
Area Forecast Discussion
National Weather Service Wilmington NC
634 AM EDT SUN MAY 22 2016
Low pressure and an associated cold front will move offshore
this morning. An area of low pressure aloft will bring a slight
chance of showers this afternoon and again on Monday. Typical
Summertime temperatures and mainly dry weather will develop by
the middle of the week with above normal temperatures into next
.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Sunday...The cold front is off the coast of SE NC and
is passing through Myrtle Beach now. Northerly winds will develop
today with cooler and slightly drier air building in.
Typically behind a cold front we don`t expect significant
precipitation chances outside of a cool-season overrunning
situation. However an upper level low centered over western New York
state will be forced southward later today and will actually end up
in northeastern North Carolina late tonight. 500 mb temperatures
currently around -12C will fall to near -16C this afternoon, then to
-20C tonight. When coupled with strong May sunshine and residual low-
level moisture we anticipate convective instability of 500-1000 J/kg
to develop with no capping. (Contingent of course on highs reaching
the mid to upper 70s) Showers and a few thunderstorms should be the
result with the highest coverage following the coldest mid-level
temperatures across North Carolina. Forecast PoPs range from 20
percent from Florence to Georgetown...up to 50 percent in the
Burgaw/Topsail Island vicinity.
Freezing levels should fall to around 9000 feet by late afternoon.
While this may increase the potential for small hail slightly, this
is not expected to be a repeat of the May 5th event that produced
widespread small hail across the Carolinas.
With the loss of heating showers should dissipate this evening with
only scattered clouds remaining overnight. Lows in the mid to upper
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...Cold mid-level temperatures associated with
upper level low pressure near Virginia Beach Monday should spark
more scattered showers Monday afternoon. Coverage should be a bit
less than on Sunday due to drier low-level conditions yielding
less instability. Temperatures should remain well below normal
with highs only reaching the lower 70s for coastal SE North
Carolina, mid 70s from Lumberton to Myrtle Beach, and maybe some
upper 70s from Darlington to Florence. (Normal highs are in the
lower to middle 80s this time of year!) Surface high pressure
building eastward from the Plains states will reach the Carolinas
Monday night providing light winds and mainly clear skies.
Radiational cooling should drop lows into the mid 50s for most
locations away from the beaches.
On Tuesday light winds and plenty of sunshine coupled with warm
advection as the upper low and surface high both move offshore
should allow temperatures to soar into the 80s away from the
beaches. Mainly clear skies will continue Tuesday night with lower
to mid 60s.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 300 AM Sunday...Middle to later half of the week will be
marked by surface high moving off the coast and weak ridging
aloft. Surface high just off the coast Wed migrates to the a more
typical Bermuda High location Thu through Sat. As the high
offshore drifts east a 5h ridge will build over region, leading to
warming and drying conditions during the period. Latest GFS and
ECMWF depicting a much stronger 5h ridge than just 24 hours ago.
The mid level ridge remains a "dirty ridge" with moisture aloft
emerging from the southwest and topping the ridge. While chances
will be very low this will at least mean isolated afternoon
convection will be possible late in the week. Will carry silent
afternoon/evening pop Thu through Sat but confidence is low.
temperatures will run above climo through the period.
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 12Z...3.9 satellite shows stratus pressing southward along
with a cold front. IFR conditions will be intermittent at FLO, while
predominate at the other terminals for the first two to three hours
of taf time. The cold front will continue to drift southward, with a
cold pool aloft moving southward as well. This cold pool may kick
off some convection this afternoon, particularly if we get some sun.
Light winds tonight with mainly scattered skies.
Extended Outlook...Possible MVFR conditions on Monday, otherwise
NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Sunday...The cold front is now through Cape Fear and
is passing Myrtle Beach at the time this is being written.
Northerly winds 10-15 kt will develop behind the front due to low
pressure off the East Coast and high pressure over the Plains
states. Typically behind a cold front we see precipitation chances
diminish sharply, however in this case unstable air aloft
associated with an upper level low pressure should help develop
scattered showers and thunderstorms this afternoon. These should
be most numerous north of Cape Fear, however there is a slight
chance even the Grand Strand waters could see a shower or storm
later today. Northerly winds will continue through tonight, with
shower chances ending during the evening.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 300 AM Sunday...Low pressure will develop Monday morning
along this morning`s cold front which should be located a couple
hundred miles offshore. The low will move northward and away from
the area, but will help to keep northerly winds blowing around 10
knots with some 15 kt winds possible Monday morning north of Cape
Fear. Scattered afternoon showers may again develop Monday due to
the cold and unstable conditions aloft.
For Monday night through Tuesday night the focus will shift to high
pressure building in from the west. This high should bring
delightful weather with light winds and no appreciable rain
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
As of 300 AM Sunday...Surface high centered just east of the
waters Wed morning will drift farther east Wed night, setting up
in the typical Bermuda High location Thu. Southwest flow is
expected across the waters through Thu night with speeds on the
low end of the 10 to 15 kt range. Sea breeze is likely to develop
each afternoon, resulting in onshore flow close to 15 kt near the
coast. Seas 2 ft or less Wed and Thu.