Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington NC
1221 PM EST Monday Feb 8 2016
weak high pressure will build in briefly today. The first of two
cold fronts will cross the area tonight...followed by the next
one...an Arctic cold front...during Wednesday. After today...look
for temperatures during this work week to trend lower...especially
during the middle to late week period when Arctic air will spread
into the region.
Near term /through tonight/...
as of 1230 PM Monday...deep East Coast trough will push a cold
front across the area this evening. Some daytime heating and
slightly higher dewpoints will combine with the boundary to create
a few showers. This will occur later this afternoon into the
evening along the coast. Temperatures will be too warm for any
frozen precipitation. The latest guidance has warmed a bit for
overnight lows and have followed suite. Most readings should
bottom out in the lower to middle 30s primarily due to the
boundary later remaining coupled.
Short term /Tuesday through Wednesday night/...
as of 3 am Monday...impressive cutoff low over the Ohio Valley to
start the period will help maintain cloud cover over the local area
on Tuesday. Shortwave rotating around the low combined with increased
middle level moisture will spread cloud cover over the area Tuesday and may
even lead to some virga. However measurable precipitation seems unlikely
given the amount of low level dry air. The shortwave also helps
drive a secondary cold front across the area. The accompanying
Arctic surge will drop 850 temperatures from around -7c Tuesday to near -13c
Combination of cold advection and cloud cover on Tuesday will keep highs
around 10 degrees below climatology. Cold advection Tuesday night will keep
boundary layer well mixed but the air mass is rather cold and lows
are likely to dip into the middle 20s. Temperatures will dip even lower
Wednesday and Wednesday night despite an increase in sunshine on Wednesday.
Cold advection will keep highs in most areas in the low 40s with
lows Wednesday night in the lower 20s. Wind chill values during the period
will be quite cold...with most areas in the 20s by day and middle teens
to single digits at night...especially Wednesday night.
Long term /Thursday through Sunday/...
as of 3 am Monday...middle level troughing will remain a dominant
feature through the period...keeping temperatures below climatology into
next week. The only feature of note during the period will be
passage of a shortwave rounding the base of the trough on Friday. There
will be a chance of precipitation as this feature passes but the limited
nature of the moisture combined with the deep west to northwest
flow suggests quantitative precipitation forecast will be very low. Plan to maintain inherited
slight chance pop for the end of the week. Shortwave helps drive a
cold front across the area Friday night...bringing a reinforcing
shot of cold air for the weekend. Medium range guidance is
showing 850 temperatures in the -15c to -20c range Sat night and sun. Not
ready to buy into temperatures that cold...especially given it is
6 days out...but it is something to keep an eye on.
Aviation /18z Monday through Saturday/...
as of 18z...increasing clouds expected this afternoon with a passing
cold front this evening. Chance for showers and brief MVFR.
Otherwise expect VFR.
Quiet conditions prevail this afternoon with nearly clear skies and
southerly winds at or below 12 kts. Will see increasing clouds this
afternoon along with increasing southwest winds...10 to 15 kts with
gusts around 20kts...ahead of an approaching cold front. Potential
for isolated to scattered showers for a few hours late this
afternoon/early evening...with any heavy downpour potentially
creating brief MVFR. Conditions improve tonight with gusty westerly
winds and prevailing VFR. On Tuesday...VFR continues with middle to
high clouds and gusty westerly winds.
Extended outlook...predominately VFR. Low confidence for MVFR/IFR
rain/snow showers Friday.
near term /through tonight/...
as of 1230 Monday...wind shift underway across the waters moreso
inland. Expect a southwest flow to develop in full this afternoon
with speeds increasing to 20-25 knots. A cold front moves across
by 0600 UTC with a westerly flow developing. Speeds will remain
elevated in a 20-25 knot range. Seas are still a little churned up
due to the storm yesterday but have dipped below small craft
thresholds. Will continue the advisory as the expected increase in
winds should do the trick with 8-10 feet eventually developing
well offshore tonight.
Short term /Tuesday through Wednesday night/...
as of 3 am Monday...period will be marked by strong west to
northwest flow...a result of strong cold advection and pinched
surface gradient. Other than a brief decrease in speeds Wednesday
morning...a pause between rounds of cold advection...winds will
remain above Small Craft Advisory headline criteria through the entire period. The
location of the middle level trough axis and surface features will
keep winds westerly through the period but the cold advection will
still be very strong. Wind gusts in excess of of gale force are
expected with potential for gusts approaching 40 knots Wednesday night
during the strongest period of cold advection. Despite the
offshore component to the winds seas will remain above 6 feet near
the 20 nm border...and along much of the southern half of
amz252...throughout the period.
Long term /Thursday through Friday/...
as of 3 am Monday...high pressure will build in from the
northwest during the period. Conditions will gradually improve on
Thursday as cold advection comes to an end and surface gradient starts
to weaken. Flow will remain offshore but speeds will drop from
around 20 knots Thursday morning to under 10 knots Thursday night. Light northwest
flow becomes southwest Friday as next shortwave/cold front combo
approach the area. Front pushes across the water Friday night with
cold advection developing as the period ends. Seas will be falling
for much of the period...dropping from 3 to 5 feet Thursday morning to 2
to 3 feet by Friday and 2 feet or less Friday night. Late in the period the
combination of southwest flow ahead of the front and increased
offshore flow behind the front will result lead to building seas.
Marine...Small Craft Advisory until 6 am EST Thursday for amz250-252-