FXUS61 KAKQ 110835
Area Forecast Discussion
National Weather Service Wakefield VA
335 AM EST Mon Dec 11 2017
High pressure builds over the Gulf coast region through Monday
night, as low pressure moves through the northern tier of the
nation. A more prominent low pressure system will move from the
Great Lakes into New England Tuesday through Tuesday night,
pushing a strong cold front through the local area. Expect
markedly colder temperatures for Tuesday night and Wednesday.
.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis reveals a broad area of high pressure
(~1030 mb) centered from the western Gulf coast across the deep
south. To the north, Low pressure genly prevails across the
Adirondack Mtns, with the associated surface front extending
back into the Ohio Valley. To the northwest, a shortwave diving
south from southern Saskatchewan toward the Dakotas, dragging a
strong cold south across the upper midwest/Western Great Lakes
today and through the Ohio Valley tonight.
Ahead of the front, lingering mid to high clouds, associated
with another vort lobe pivoting across the region with the
departing upper trough. Skies again turn mainly sunny behind
this feature this morning. Temperatures do moderate slightly,
with milder highs today into the mid-upper 40s most areas to
lower 50s SE coast.
After a clear start, sky will become Partly to mostly cloudy
late Mon night ahead of the approaching front to the west.
Veering low-level flow to the S-SW should bring a slightly
milder night with early morning lows in the low to mid 30s.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Day begins with potent upper shortwave pinwheeling across the
interior northeast, with the strong cold front pushing across
the area from late morning through early evening Tuesday. Should
be enough pre-frontal SW flow Tue to bring one last relatively
mild day Tuesday, with highs into the mid- upper 50s SE to the
upper 40s NW. Turning blustery and dry late in the day from NW
to SE. Wind gusts to 20 to 30 mph Tuesday afternoon...gusting to
30 to 40 mph Tuesday night.
Temperatures quickly tumble into the 20s/30s early Tuesday
night, with early morning lows in the teens NW to 20s elsewhere
Wednesday morning under a clearing sky. Brisk NW winds will
quickly knock wind chills down into the 10-20 F range Wed
morning. Even with mainly sunny skies Wed, highs will struggle
to get above the lower 30s N and mid 30s S...with wind chills
remaining in the 20s or colder.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A progressive WNW flow pattern is expected for the latter half
of this week through next weekend, featuring a series of nrn
stream (moisture-starved) clipper systems. The first wave
pushes through during the Wednesday night/Thursday timeframe.
The 10/12z ECMWF is about 12hrs quicker than the GFS, but
regardless PoPs are less than 15% with limited moisture and
downslope flow. Another wave quickly follows Friday. The GFS is
more nrn stream dominated while the ECMWF pushes a srn stream
wave off the Southeast coast. Again, there is little support for
pcpn locally, so forecast PoPs are less than 15%. Shortwave
ridging prevails Saturday with another quick moving trough
pushing through the region Sunday. High temperatures Thursday-
Saturday will generally be in the 40s to around 50F SE, then
low/mid 50s by Sunday as the aforementioned trough will provide
mixing with limited CAA. Low temperatures will primarily be in
the 20s for much of the area to low 30s SE later this week, and
then rise to the upper 20s/mid 30s (upper 30s/around 40F far SE)
by the weekend.
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR conditions expected through the 06z TAF period. SCT/BKN mid
to high level clouds will push across northern sections of the
area during the overnight, clearing towards morning. Winds will
be 10 kt or less from the SW-W tonight and Monday.
Outlook: Expect VFR conditions to prevail for the most part
through the week, though winds are expected to become strong and
gusty later Tue and Tue night into Wed with the passage of a
strong cold front.
Ended the SCA hazards over the ocean with this forecast package as
seas have dropped below 5 ft. Sfc high pressure builds over the SE
states tonight, and with a slight increase in the pressure gradient,
have hoisted a marginal SCA for the Bay for a short period of 15-20
kt winds. Sub-sca conditions then into the day Mon as a clipper
system approaches the OH Valley. This system will drag a strong cold
front through the waters on Tue, with SCA conditions expected over
much of the marine area lasting from Tue through Wed. Low-end gales
are psbl by Tue night, esply over the coastal wtrs.
MARINE...Small Craft Advisory until 7 AM EST this morning for