Scientific Forecaster Discussion
fxus62 kilm 251939
Area forecast discussion
National Weather Service Wilmington NC
339 PM EDT Thu may 25 2017
a vigorous upper level disturbance will bring showers and some
thunderstorms this afternoon, some of which may contain small
hail and strong gusty winds. High pressure will build across the
area tonight and Friday and persist into the weekend, bringing
dry weather and increasing heat. A cold front will reach into
the Carolinas early next week, finally moving off shore by mid
Near term /through Friday/...
as of 300 PM Thursday...a vigorous shortwave rounding the base
of the trough and its associated cold pool is bringing the last
of the showers and a few thunderstorms across the forecast area
this afternoon. Through late afternoon there is a potential for
mainly small hail and strong gusty winds with the strongest
showers/thunderstorms. This activity will weaken through 6 PM as
it moves offshore. Behind the convection, the skies will be
clearing this eve and remain so overnight. The incoming airmass
is much cooler and certainly much drier. Dewpoints will be in
the 50s through Fri, unseasonably comfortable for most this time
of year. Lows tonight will be in the upper 50s to lower 60s.
Highs on Fri will be in the mid 80s with very comfortable
humidity levels and mainly sunny skies.
Short term /Friday night through Saturday night/...
as of 300 PM Thursday...high pressure south of the area
extending from the Gulf of Mexico across to the Bahamas will
produce a deep west-SW flow over the area through the period. This
will maintain generally quiet weather but minor perturbation
will ride across the top of the mid to upper ridge extending up
from the Gulf of Mexico. This may produce some periods of
clouds, but the best energy will remain just north and therefore
will maintain a rain free forecast for most of the period. Have
included a low end chc of pcp overnight Sat over northern tier
of forecast area as deep enough low pressure traverses across
the Virginia/NC border with a trailing front reaching back into NC.
Otherwise, expect a good amount of sunshine on Fri. The h5
heights will continue to rise through Fri night and will remain
heightened and 850 heights Jump Up near 16c on Saturday. The
winds will back at the sfc bringing dewpoint temps up through
the period and winds aloft will have a decent westerly downslope
component. Therefore expect warming trend with overnight lows
in the mid 60s Fri night up to around 70 Sat night. Daytime high
temps on Saturday should Max out around 90.
Long term /Sunday through Thursday/...
as of 300 PM Thursday...the weather will becoming increasingly
unsettled through the latter half of Memorial Day weekend. We
will basically remain under the grips of high pressure to our
south on Sunday with a warm and moist SW return flow. Aloft, the winds
will be more westerly atop a ridge extending up form the Gulf of
Mexico. Initially on Sunday, the ridge builds north with
increasing subsidence and dry air aloft into the early afternoon,
but the ridge flattens out as mid to upper trough digs down
from the upper Great Lakes. This will push cold front closer to
the area. There will be a general increasing potential for
clouds and showers/tstms late sun through mid week ahead of this
slow moving front. It looks like the most widespread convection
will come on Mon into tues as the front gets a push south and
east into and through the forecast area. Expect the surface
front to make it just south by Wed, but it remains aligned SW to
NE near or just south of area as a broad upper trough remains
over the eastern Continental U.S.. this front looks like it will remain
close enough to produce unsettled weather over at least coastal
portions of the forecast area through the remainder of the work
week. Overall convection should be more localized sun into Mon
and become more widespread late Mon into tues with a possible
break on Wed as front moves south with continued convection
mainly along the coast or south on thurs.
Mid level heights will continue to rise through sun with GFS
showing peak sun aftn but remaining high through Mon. This will
maintain very warm temps both sun and Mon, crossing into the 90s
most places. Max temps will run in the 80s through the rest of
the period dampened by clouds, and the moist air mass will keep
overnight lows up around 70 most nights in a more summerlike air
mass with a slight cooling as front passes through tues night
Aviation /18z Thursday through Tuesday/...
as of 18z Thursday...a cold pool aloft is bringing the last of
the showers and a few thunderstorms across the terminals. This
activity will be moving offshore and weakening during the late
afternoon. Brief MVFR is possible with the showers through
20-21z. Thereafter skies will be clearing and VFR is expected
through the remainder of the valid taf period. The winds will
continue to gust up to 25 to 30 kt through sunset and then
winds will diminish to 10 to 12 kt or so.
Extended outlook...MVFR conditions possible in scattered
showers and thunderstorms sun through Tue.
near term /through Friday/...
as of 300 PM Thursday...Small Craft Advisory conditions ongoing
across the waters. Deep mixing will allow for sustained SW to west
winds of 20 to 25 kt with a few gusts up to 30 kt through this
eve and mainly west winds at 20 to 25 kt tonight. Winds on Fri
will be 15 to 20 kt, diminishing to 10 to 15 kt during the
afternoon. Seas will be up to 5 to 8 ft this eve, subsiding to
below Small Craft Advisory criteria by sunrise. Seas on Fri will
be subsiding in general offshore flow, down to 2 to 4 ft during
Short term /Friday night through Saturday night/...
as of 300 PM Thursday...west to SW return flow around 10 to 15
kts will continue around high pressure extending from the Gulf
of Mexico east to the Bahamas. Seas will be gradually
diminishing through Fri night down to 3 ft or less.
Winds and seas will increase slightly late Sat through Sat
night as low moves across Virginia/NC border with trailing front. Seas
will spike up a bit Sat night up to 3 to 4 ft.
Long term /Sunday through Tuesday/...
as of 300 PM Thursday...high pressure to the south will
maintain a SW return flow 10 to 15 mph through much of the
period. Seas will remain between 2 and 4 ft through the period.
SC...beach hazards statement until 9 PM EDT this evening for scz054-
NC...beach hazards statement until 9 PM EDT this evening for ncz106-
Coastal flood advisory from 8 PM this evening to midnight EDT
tonight for ncz107.
Marine...Small Craft Advisory until 6 am EDT Friday for amz250-252-254-