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fxus62 kilm 251815 
afdilm

Area forecast discussion
National Weather Service Wilmington NC
215 PM EDT Tue Jul 25 2017

Synopsis...
isolated to scattered storms will become more numerous Friday
and Saturday, as a moderately strong frontal system arrives
at the coast. A slight cooling and drying trend may occur Sunday
into early next week, as this system is kicked offshore.



&&

Near term /through Wednesday/...
as of 215 PM Tuesday...potential for widely scattered showers
and a few thunderstorms with the sea breeze through the
afternoon. Additional storms are possible tonight as a cold
front drops southward across the forecast area. The front is
expected to drift south of the forecast area during Wednesday
and become increasingly diffuse. Dewpoints will lower across the
northern zones while the b best chance for
showers/thunderstorms will be across the southern zones during
the day. Northeast to easterly wind in the wake of the front
will help hold temperatures to the mid 80s at the beaches on
Wednesday. Followed a blend of mav/met numbers through the
period.

&&

Short term /Wednesday night through Thursday night/...
as of 215 PM Tuesday...very interesting synoptic setup through
mid- week despite very weak surface features and gradients. The
interesting aspect is focused mostly at and above 500mb as a
nearly stationary shortwave spins across North Florida in response to a
persistent ridge in the west, and jet level winds increase and
dive SW between the ridge and the trough. This drives a strong
deformation axis across the Carolinas where NE 250mb winds
converge with more typical westerly 250mb winds along a jet axis
off the coast. As is typical with deformation axes, most of the
precip occurs southeast of this feature, as drier air advects behind
it. This is clearly evident on forecast profiles with
exceedingly dry air developing above 600mb, which should limit
convective coverage considerably on Thursday. This dry air,
combined with weak confluence into the deformation axis, and a
weakening surface front to the south will preclude much in the
way of convection Thursday, and have opted to remove any mention
even along the sea breeze despite temperatures around 90.
Wednesday night will be dry as well, minus a few isolated
showers well south, with mins in the low 70s, while subtly
increasing column moisture ahead of an approaching front and
developing S/SW winds will keep mins several degrees warmer
Thursday night, falling only into the mid to upper 70s.

&&

Long term /Friday through Tuesday/...
as of 215 PM Tuesday...an unseasonably amplified upper trough
becomes the primary feature and key player for late week and
weekend sensible weather. This will translate to elevated rain
chances late Friday and Saturday as this system Ushers a fairly
strong surface trough across the coast. European model (ecmwf) and GFS clear
this boundary off the coast into early Sunday, the GFS much
stronger. Both suggest therefore some drying and cooling, but
of differing magnitude. A blend still brings surface dewpoints
into the 60s early next week, helping to take off the bite of
high absolute humidity values. A dry mid-level air intrusion
will curtail deep convection Sunday through early next week. A
few showers could linger and remain favored closer the coast in
proximity to higher moisture and the oceanic front, but the
overall coverage should trend down Sunday Onward. Temperatures
slightly above normal Friday at the start of the period, may dip
below normal from Sunday forward, as cool air advection pushes
into the balmy Sea Air.

&&

Aviation /18z Tuesday through Sunday/...
as of 18z...VFR conditions will prevail through much of the
however could see some tempo cigs in or near any convection.
Kilm may see -shra/thunderstorms and rain with the sea breeze this afternoon,
with lesser chances at kcre/myr. A cold front dropping south
across the region tonight into Wednesday will promote
additional, chances for storms. Highest chances during Wednesday
will be at the SC terminals. Otherwise, tempo cigs due to
stratus and stratocumulus are possible during the early morning
hours, especially kflo/klbt.

Extended outlook...possible MVFR conditions Thu morning and with
some flight restrictions with any convection Saturday and
Sunday.

&&

Marine...

Near term /through Wednesday/...
as of 215 PM Tuesday...a cold front will drop south across the
waters during tonight. Southerly winds ahead of the front will
become variable for a brief period tonight prior to shifting to
a northeast-easterly direction overnight into Wednesday
morning. Easterly flow will prevail through Wednesday afternoon
with speeds of 10-15 knots. Seas are expected to be 3 ft or less
through the near term period.

Short term /Wednesday night through Thursday night/...
as of 215 PM Tuesday...a cold front will be dropping across the
southern waters Wednesday night before stalling south of the
area on Thursday. This leaves east/NE winds less than 10 kts
Wednesday night, gradually shifting to east/southeast and eventually
coming around to the SW Thursday night as the front dissipates
and high pressure becomes dominant once again. Speeds through
the period will be 10 kts or less, with the exception being
within the near shore sea breeze Thursday when gusts to 15 kts
are possible, and again very late Thursday night when 10-15 kt
winds will overspread the waters. These light winds will allow
the southeast swell to be dominant until the wind wave amplifies
Thursday night. Seas will be 2-3 ft through the period but the
average period will begin to shorten late.

Long term /Friday through Sunday/...
as of 215 PM Tuesday...wind direction will become changeable
this period, but the good news is that wind-speeds will decrease
into the weekend, as a front lays up along the coast then
offshore. Thunderstorms will become more numerous along the front
however Friday night and Saturday, so a radar update should be
on the checklist first part of the weekend. Gusts to 20 knots from
SW likely Friday out ahead of the front, and could be stronger
so an Small Craft Advisory is not out of the question yet for Friday. Seas 2-4
feet this period because of initially gusty winds, then because
of swell over the weekend. Thunderstorms will decrease in coverage
Sunday, although the Gulf Stream and outer waters may remain
unsettled due to the offshore front.



&&

Ilm watches/warnings/advisories...
SC...none.
NC...none.
Marine...none.

&&

$$

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