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Area forecast discussion...updated 
National Weather Service Baltimore Maryland/Washington District of Columbia
940 PM EDT Friday Aug 28 2015

high pressure remains over the region through the weekend...and
then slides offshore early next week.


Near term /through Saturday/...
another quiet night under high pressure. Not sure whether any fog
will develop overnight. Winds become light southerly overnight but
blended tpw product does not show any moisture advection.

Previous afd...

Tonight...some patchy light fog is possible in the typical
valleys/rural areas. Lows will inch up compared to Thursday night
coincident with dew points....with most locations in the 60s.


Short term /Saturday night/...
the surface high inches east on Saturday. The trough over the Great
Lakes will get sheared out and will likely have little affect on the
local area. Low/middle level ridging ends up just east of the
area...which will allow southerly flow to be established. There may
be enough moisture return for an isolated shower or storm to develop
over the high terrain and adjacent valleys...but overall atmosphere
still looks fairly stable. Highs will reach the middle to upper 80s in
most locations.

With dew points beginning to rise by Saturday night...patchy fog
will again be possible South/West...although some cirrus could begin
to spill across the area. Lows will also be a little more
mild...with middle 60s common to around 70 in the urban areas.


Long term /Sunday through Friday/...
weather looks to remain fairly quiet to end the last weekend in Aug. High
pressure moves offshore..the next cold fnt is hundreds of miles to the
west...and Erika is between the Bahamas and Cuba. This will leaving the middle
Atlantic in a warm air mass. Highs sun u80/l90s...Sun night mu60s xcpt
l70s along the Bay/in cities. No real change expeceted for Monday.

Isolated cnvtcn sun-Monday will be possible west/ incrsg humidity...primarily
over the mountains

Upper level low cutting off over Great Lakes/Ohio Valley Monday will
slowly move east to eastern Pennsylvania and stalling Wednesday.
Surface low center that forms over area Tuesday will stay through
end of the period. Support for convective development meager during
early half of period but will strengthen during latter half.


Aviation /02z Saturday through Wednesday/...
have introduced MVFR br at cho tonight...although confidence is
low...and cannot totally rule out development at mrb as well.
Similar possibilities of br Saturday night. Light and vrb winds
this afternoon and tonight will become predominantly southerly
Saturday...although speeds will be less than 10 knots.

VFR conds expeceted sun/Mon. Light fog possible overnight iad/mrb/cho both
ngts. Isolated afternoon/evening thunderstorms possible both days...primarily over the


high pressure to the north will slide east Saturday and provide dry
weather. Light and variable winds through tonight will become predominantly
southerly on Saturday. This may allow some speeds of up to 15 knots
on the Bay by Saturday evening...but Small Craft Advisory conditions are not
expected at this time.

Winds expeceted to remain below Small Craft Advisory values sun and Monday.


Lwx watches/warnings/advisories...
District of Columbia...none.


near term...lfr
short term...abw
long term...cem

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