Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
1011 am EST Sat Mar 8 2014
high pressure will control the weather pattern today. A cold front
will pass through the area tonight and high pressure will return for
early next week. A cold front will move into the area Tuesday night
and low pressure associated with this boundary will impact the area
during the middle portion of next week.
Near term /through tonight/...
warm day on tap for the middle Atlantic today. 12z radiosonde observation showed a
strong inversion at the surface that is expected to mix out this
afternoon. Mixing this morning has already led to temperatures in the 40s
with some spots around 50. BWI jumped from 43 degrees to 51 in the
last hour. Downsloping flow will continue today and expect temperatures
to keep climbing into the middle to upper 50s this afternoon and in
the low 60s in the northern Virginia Piedmont. Although a lot of snow from
this past week will melt today areas still covered in snow will
likely see temperatures closer to low to middle 50s. Middle to high level clouds
will increase from west to east today.
the cold front will pass through the area late tonight. Increasing
clouds and a few showers are possible ahead of the front.
However...precipitation will be light and most of the time will be
dry since little moisture is associated with the boundary. There
will more showers along and west of the Allegheny Front due to an
upslope flow. There will also be enough cold air for rain showers
to change to snow showers after midnight. Light snowfall
accumulations are expected across these areas.
Short term /Sunday through Sunday night/...
behind the overnight shortwave passage late Sat will be another
relatively warm day on Sunday. Dry and breezy northwest winds will do their
part to cut down on temperatures. Daytime highs in the u40s will be at
least a couple degree below average. Not a potent shortwave passage...so
the subsidence region behind it won't be particularly strong. Surface
dewpoints will only drop a few degrees over a several hour
period...and winds will peak in the 15-25mph range during the late
morning-afternoon hours. A little bite to the air west/ these winds and
relatively cool temperatures but not nearly as cold as the average. Conditions
in recent days. Skies will clear out through the middle-late morning and
plenty of sun will be around for the afternoon hours.
Fast upper flow will be oriented northwest-southeast bringing the next of 3 upper
waves / clippers in succession. Winds will drop off Sun night...and
the drier air will allow temperatures to drop back toward the freezing mark
overnight but not much below the l30s.
Long term /Monday through Friday/...
including the Sat night upper wave...clipper-after-clipper will
again be a part of the story but the subsequent features look to
pass by to our north and make little impact on the area into early
next week. The next clipper will only bring some middle clouds to the
northern sections of the County Warning Area early Monday. But this wave and another fast
on its heels will do little to prevent the area from cracking the 60
degree mark both Monday and Tuesday. A large surface high residing over the southern
Atlantic coast will help push warmer air from the south over the area.
With the tighter pressure gradient from the clippers passing by to our
north...SW winds will strengthen and usher in this warmer airmass at
a faster rate.
Those looking-forward to some relief from the cold will get at least
a couple of days - Monday and Tuesday - before another reminder that
conditions can change quickly this time of year. Still a good amount
of divergence in the long range depictions of the Wednesday low pressure
passage. The 00z GFS has washed-out its earlier compact low pressure
system from the upper Midwest and is now an open wave that meets up
west/ a Gulf Coast upper level system...off the Atlantic coast. The 00z
Euro hangs onto the western solution...where the upper Midwest wave
meets up west/ the Gulf moisture across the eastern Seaboard and pulls-in
some colder air on the backside of the exiting precipitation. Either
solution keeps at least a chance of some wintry mix up across the
northwestern quadrant of the County Warning Area early Wednesday - and then again on the backside
of the system early Thursday morning. Leaning toward a plain-rain passage
for much of the region west/ highs in the 40s/l50s during afternoon.
Behind this system will be a steady-gradual warm-up into the next
weekend - each day a few degree warmer than the last. High pressure
will make its way over the southeast over the 2-3 day period before
the next longer-term passage of a deep upper trough that will
encompass the East Coast next weekend.
Aviation /15z Saturday through Wednesday/...
VFR conditions are expected most of the time through tonight.
Westerly winds around 10 knots are expected this afternoon before
diminishing this evening. A cold front will pass through the
terminals late tonight. Ceilings will approach MVFR levels during this
time and a few showers are possible. Wind will shift to the
northwest behind the front toward morning.
Skies will clear out on sun...W/ a pick-up in northwest winds through the
daytime hours. High pressure Monday and Tuesday west/ dry conditions and light
winds other than some gusty winds over the mountains on Tuesday. A low
pressure system's passage on Wednesday will bring some precipitation to the
area...then move off the coast by early Thursday.
winds will shift to the west-southwest ahead of an approaching cold
front today. Despite a deep mixing layer...wind gusts have been
capped below Small Craft Advisory criteria due to the relatively colder waters. The
cold front will pass through the waters late tonight. Winds will
shift to the northwest toward Sunday morning.
A weak upper wave will move off the coast early sun...ushering in
gusty winds from the northwest for the daytime hours - west/ marginal Small Craft Advisory gusts
until late afternoon. High pressure will build in for early next week and
keep conditions quiet through early Wednesday. A low pressure system will
cross the region on Wednesday...bringing a period Small Craft Advisory gusts behind the
system on Thursday. High pressure will settle down the area's weather and
winds through the end of the week.
District of Columbia...none.
Marine...Small Craft Advisory from 10 am to 6 PM EDT Sunday for