Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 280800

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Sun Aug 28 2016

High pressure will remain over the Mid Atlantic through Monday before
moving offshore. A cold front will move through the area early Thursday.
High pressure returns for late in the week.



Surface high pressure is currently over northeastern Maine and
heading further east into Atlantic Canada...while strong ridge of
high pressure aloft continues to dominate overhead. Onshore flow has
started to bring in some of the anticipated low clouds but unsure
just how far west they can penetrate before breaking up this
morning. The onshore flow will keep temps a bit cooler than
yesterday across much of the region with decreasing influence as one
heads west...especially west of the Blue Ridge. In the far west
enough instability looks present to provide a stray thunderstorm
later today though think this will be confined to the Allegheny
Front. Otherwise...still fairly hot by this afternoon by late August
standards with some sun across most of the area.

Any storms dissipate early tonight and the flow will shift more
southerly. It will remain light however so think patchy fog is
possible in the interior again. Lows remain on the mild side.



Approaching weak front with shortwave will result in slightly warmer
and more humid conditions on Monday...but not heat advisory levels.
Forcing and greater instability also likely to result in a better
chance of t-storms...though think they stay mainly NW of the metro.
Some may drift into the metro or fire on boundaries near the metro
during the evening. This boundary sags south and weakens on Tuesday
and the forcing mostly passes us. Thus overall a lesser chance of t-
storms Tuesday with slightly cooler temps...but with the boundary
hanging up in central VA these areas may actually have a better shot
at storms.


Expect high temperatures to climb to around 90 again Wednesday to
end both the month and meteorological summer. See the climo stats
below for the summer so far.

A cold front dropping into the area may bring a threat for
showers and thunderstorms closer to the metro areas Wednesday

A showLight winds and no risk of storms through early Monday. Risk of
storms increases late Monday into Monday evening. Risk declines
Tuesady. Winds stay sub-SCA Monday and or thunderstorm
will remain possible Thursday across southern portions of the area
as some models/ensembles are slower with the southward progress of
the cold front. Temperatures will take a drop to begin September
with highs in the low to mid 80s. Thursday night will provide some
of the most comfortable temperatures area has experienced
recently. Lows will drop into the low to mid 60s east of the Blue
Ridge...and mid to upper 50s west.

Friday should see highs in the lower 80s then rising for the
holiday weekend. Fly in the ointment is that the Euro is
projecting low pressure moving over the Outer Banks next Saturday
night. This model keeps this east of the CWA but holiday travelers
should keep an eye on the development in the days ahead.



Main concern is low clouds trying to push west into the terminals
early this morning. Think they stay away from DCA but they may reach
BWI so have tempo group. They should not last long and we should be
VFR bulk of day. Inland the early fog will dissipate quickly as
well. Chance of t-storms nil at terminals today. Patchy fog mainly
inland again tonight then a better risk of mainly inland t-storms on
Monday. Something may drift towards metro terminals during the eve.
Risk of t-storms looks a little lower Tuesday in the metro and MRB
but may be higher CHO where front hangs up.

VFR Wednesday. A thunderstorm is possible Wednesday afternoon as
a cold front approaches.



Light winds and no risk of storms through early Monday. Risk of
storms increases late Monday into Monday evening. Risk declines
Tuesady. Winds stay sub-SCA Monday and Tuesday.

Winds below SCA values Wednesday. Thunderstorms will be possible
during the late afternoon/evening.


Ranking of summer 2016 in terms of average temperature (JUN 1 - AUG 27)

Site          Rank                    Average Temperature

DC   3   80.5
Balt          18  77.3
IAD            3                            77.3




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