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000
fxus62 kilm 151154
afdilm
area forecast discussion
national weather service wilmington nc
654 am est sun feb 15 2009
. synopsis...
an upper level disturbance will move across the carolinas sunday
night into monday. high pressure will build in behind this system
through wednesday. at this time a strong cold front will approach
from the west ... slated for an early thursday passage. high
pressure will build in for the remainder of the week and into the
weekend.
&&
. near term /through tonight/...
as of 3 am sunday ... cold front has cleared the forecast area as of
08z. modest surge of colder and drier air will overtake the area
into this afternoon. for today ... forecast area will be in between
high pressure centered across the northern plains and mid west and
low pressure moving along the southern gulf coastal states. this
area of low pressure will cross the fl peninsula this eve and then
move ene ... passing well s and e of our area as it moves into the
open atlantic. precipitation shield associated with this area of low
pressure has the potential to brush the coast tonight ... but
significant rainfall is expected to remain offshore.
cloud cover will be at a minimum this morning into this afternoon
with clouds on the increase during the afternoon and eve.
however ... even with sunshine ... temps will fall short of
climatological normals in most places.
a very potent shortwave embedded in nw flow will affect the area
late this eve and overnight. dynamically forced showers associated
with this feature should race across the area. as column
cools ... liquid showers could mix with snow showers. dendritic growth
zone never becomes saturated ... however partial thicknesses indicate
a mixed precipitation event is possible after 06z. available
moisture within the column will be low. precipitable waters will be
near a half inch ... dropping as daybreak mon approaches. still ... as
we have seen in the past with these strong upper level features
they are capable of squeezing out some light qpf.
no snowfall accumulation is expected as temperatures will be above
freezing while the precipitation is falling and soil temps will be
in the mid 40s or higher. the rate of precipitation is not expected
to be heavy enough to overcome these factors. minimums early mon
morning will be in the mid 30s.
&&
. short term /monday through tuesday night/...
as of 3am sun ... upper air disturbance streaking acrs the area
while strong caa underway may be enough to touch off a sprinkle
(flurry?) to start mon but strong drying soon behind. looks like a
good candidate for falling pm temps. most if not all areas below
freezing mon night. caa shuts down tues and may even begin to
weakly reverse. sfc ridge ends up offshore tues night but only
barely ... keeping the h8 waa from making much a difference in sfc
temps compared to mon night. increasing clouds may have more of a
hand in making tues night a few deg warmer not only monday night
but also currently fcst.
&&
. long term /wednesday through saturday/...
as of 3am sun ... strengthening warm and moist advection on wed
ahead of strong cold front. rain chances inc as the day wears on
and the boundary approach in addition to increasing jet. best rain
chances with actual fropa wed night and then pretty quick drying
and cooling thereafter. temps below climo for the remainder of the
long term with bigger deviations expected by day. fairly strong
upper vort rounds the deepening eastern trough on sat but it
should be moisture starved.
&&
. aviation /12z sunday through thursday/...
at 12z all terminals reporting vfr. high pressure will continue to
build into the terminals this morning in the wake of a cold front
now situated well south of the terminals. this will keep the low
levels dry ... but mid and upper level cloudiness will be on the
increase through the morning hours. winds will be north to northeast
5 - 10 knots ... with occasional gusts to around 20 knots at the coastal
terminals. wind speeds will decrease and directions veer to the
northeast towards afternoon. not much change expected through this
afternoon with northeast winds 5 to 10 knots and mid level ceilings
generally above 12k.
this evening an area of low pressure will pass well offshore of the
coastal terminals as a strong short wave approaches flo/lbt from the
west. as the strong short wave approaches flo/lbt shortly after 00z
expect only patchy rain out of a mid level layer. as the short wave
approaches the coastal terminals around midnight expect ceilings to
drop to 4 - 6k. coastal terminals should see the same patchy light
rain scenario with the heaviest of showers remaining offshore.
there is a potential for some light snow in the pre - dawn hours most
likely at lbt but will re - evaluate this further in the 18z tafs.
extended outlook through tuesday ... chance of mvfr ceilings monday
morning. vfr monday afternoon through tuesday night. a large and
complex low pressure system sets up wednesday ... with rain and low
ceilings possible wednesday into thursday.
&&
. marine...
near term /through tonight/...
as of 3 am sunday ... modest ne surge will be underway to start the
period. winds will be strongest prior to noon. will headline
exercise caution all waters for winds near 20 kt threshold. surge
will wane through the afternoon. low pressure will pass s and e of
the waters tonight. as this system strengthens well offshore...
expect winds to again be on the increase tonight. wind direction
will be predominately from the ne this period. seas will likely
remain below 5 ft except near frying pan shoals.
short term/monday through tuesday night/...
as of 3am sun ... moderately strong gradient mon and mon night
between encroaching high and deepening storm system well offshore.
quite a level of gustiness expected on account of turbulent mixing
in strong caa regime. the offshore fetch should prevent seas from
building to flag levels but winds may require scec headlines.
gradient eases for the rest of the short term pd as high builds in
and then starts to veer towards the end as the ridge moves
offshore.
long term/wednesday through thursday/...
as of 3am sun ... winds and seas are progged to increase
dramatically in pre - frontal warm advection zone ahead of cold
front. gradient looks quite strong and only ssts will act to
inhibit the growth of both. this should keep gales out of the
forecast but small craft advisory will still be easily met for
both winds and seas. a turn to offshore wind by thursday behind
fropa will start to knock down seas slightly especially near shore
while the decrease in speeds has a similar effect.
&&
. ilm watches/warnings/advisories...
sc ... none.
nc ... none.
marine ... none.
&&
$$
synopsis ... mbb
near term ... rjd
short term ... mbb
long term ... mbb
aviation ... mrr