Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
132 PM EDT Tuesday Mar 11 2014
high pressure will push off the southeast coast through tonight...as
a cold front approaches from the west. The front will cross the
region late Wednesday into Wednesday night. High pressure returns
Thursday and Friday.
Near term /until 6 PM this evening/...
very nice weather this afternoon...as surface hi pressure slides east of the southeast CST.
This will provide a low level flow from the west-southwest. Expect generally a
mostly sny sky this afternoon...resulting in temperatures rising well above
normal. Hi temperatures will range from the middle to upper 60s on the eastern
shr...to the lower to middle 70s elsewhere.
Short term /6 PM this evening through Thursday/...
increasing and thickening cloudiness Tuesday night...ahead of surface low pressure
approaching from the west. Isolated rain showers may move into extreme western cnties
toward Wednesday morng. Low temperatures from the l/m40s to l50s.
That low will intensify as it continues NE to just off the New England
CST Wednesday into Wednesday night. Will spread likely probability of precipitation across much of the forecast area
Wednesday morning. 00z/11 models suggest that initial area of precipitation begins to
exit to the east-northeast Wednesday afternoon before a cold front arrives from the west (lt in
the afternoon/eve) west/ its possible scattered precipitation (including low probability for t).
Becoming breezy/windy (gusts to 25-35 mph) by afternoon ahead of that
cold front. Hi temperatures from the m60s to l70s.
Much drier and colder airmass then filters into the region Wednesday night
and Thursday on strong northwest winds (ptntl gusts to 40-45 miles per hour...especially eastern
portion). After evening rain showers chances...becoming mostly clear to pcldy Wednesday night
with low temperatures ranging from the middle 20s to middle 30s. P/msny on Thursday
with hi temperatures only in the l/m40s.
Long term /Thursday night through Tuesday/...
cold start to the extended forecast Friday morning as strong northwest flow
and cold air advection will continue behind the low pressure system
moving off the coast. Do not expect a prolonged period of cold temperatures
as high pressure that builds in from the west quickly moves east and
a return flow results helping to push a warmer airmass back into the
Flow remains out of the SW on Sat as models indicate convergence
along a surface trough may produce a line of light showers on Sat.
High pressure to the north begins to nose down into the middle-Atlantic
Sat night ahead of the next approaching surface low that will be
forming in the southeast US and moving NE on Monday. Chances for
precipitation increase Sun night into Monday with the approach of
that low pressure system.
Expect temperatures in the middle 50s for Friday...rising into the low 60s for
the weekend. Cold morning temperatures in the 20s expected for Friday with
upper 30s for lows prognosticated through the weekend.
Aviation /18z Tuesday through Sunday/...
continued VFR conditions through tonight with just some high
clouds. On Wednesday a strong cold front will move across the area
during the late afternoon and evening. Some showers will develop
well ahead of the front as the moisture begins to return on
Wednesday. This could bring some showers to kric before 18z.
However VFR conditions should continue through 18z. A line of showers
and possibly thunderstorms will cross the area during the late
afternoon and evening. These could produce brief MVFR or IFR
conditions with strong wind gusts. Skies will clear after the
front moves off the coast Wednesday night with VFR conditions
returning. It will continue to be windy on Thursday.
benign marine conditions expected today into tonight as surface low pressure
passes well north of the area and the pressure gradient remains weak over the
waters. SW winds avgg 5-10 knots this morng will shift to the S then southeast
this afternoon and tonight as low pressure approaches form the west. The pressure
gradient will tighten through the day Wednesday as the low passes northwest of the
waters. Despite still cool waters...surface pressure falls warrant a Small Craft Advisory for all
waters Wednesday afternoon. Cold front associated with aforementioned low pressure will
cross the waters Wednesday night...with gale force west/northwest winds possible following
the frontal passage. Will end the Small Craft Advisory around midnite Wednesday night (4th period) for
now with the dayshift deciding whether/where gale headlines are necessary
thereafter. Expect waves to increase over the Bay form 3 feet midday
Wednesday to 4-5 feet Wednesday ngt/Thu. Seas will approach 7-8 feet out 20 nm
(especially over northern wtrs) and 3-5 feet nearshore. Winds will not
subside to below Small Craft Advisory thresholds until Thursday night as hi pressure builds in form
Marine...Small Craft Advisory from 1 PM Wednesday to 1 am EDT Thursday