Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 210800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Thu Sep 21 2017

.SYNOPSIS...
High pressure both at the surface and aloft will build overhead
through the weekend. Hurricane Maria may approach the mid-
Atlantic coast middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Early this morning, Jose continues to meander off the coast of
New England, well to our east, while a ridge of high pressure is
building over the midwest aloft. At the surface, the high
pressure ridge extends along the Appalachians. The only fly in
the ointment is the trough which brought showers and
thunderstorms to western Virginia yesterday - this system
remains nearby, but is slowly sinking south. Its influence may
still bring a stray shower to the far southwestern corner of the
CWA this afternoon, but odds look considerably less than
yesterday, so have just included some slight chance POPS for
now. Otherwise, patchy fog this morning should break for another
mostly sunny and warm day, with another clear to partly cloudy
night with more patchy fog. The air mass is drier than it was 24
hours ago, and we have not had significant rain in a couple
weeks, so dense fog is not going to be as easy to come by as it
might otherwise be. However, a few spots may drop to 1/4 mile
early this morning and again late tonight, but not up to Dense
Fog Advisory calibre. Highs today will be well into the 80s once
again, with lows tonight in the 50s and 60s once again. Winds
will be light.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
High pressure ridge at the surface will remain more or less
stationary over the Appalachians through Saturday night. Aloft,
ridge of high pressure centered over the Midwest will continue
to extend its influence across our region, while Jose will
continue to meander over the northwest Atlantic near New
England. End result will be continued warm and dry weather, with
the only real weather concern being extent and coverage of
patchy fog each morning. Highs will be well into the 80s Friday
and Saturday with lows in the 50s and 60s. Winds will be light.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Strong ridge of high pressure will remain in place through at
least Sun and likely beyond albeit weakening. With regards to
the track forecast of Hurricane Maria, global models show Maria
having a similar track to Jose tracking a little west of 70W.
Please consult NHC forecasts for more info on Hurricane Maria.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Main concern through the next several days is patchy late night
and early morning fog, mainly at MRB and CHO. Vis could drop
briefly to IFR at either or both sites each of the next three
mornings. An MVFR restriction is not out of the question at the
other terminals (except DCA). Otherwise, VFR with light winds
should prevail through Saturday night thanks to high pressure.

No sig wx wx expected through Mon.

&&

.MARINE...
High pressure will provide dry weather with sub-SCA winds
through Saturday night.

Global models show winds strengthening on Tue as pressure
gradient tightens as Hurricane Maria gets closer to the mid-Atlc
coast middle of next week. For now, it appears small craft
advisories are possible.

&&

.TIDES/COASTAL FLOODING...
Minor coastal flooding will continue at most of the sites over
the next several days.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory until noon EDT today for DCZ001.
MD...Coastal Flood Advisory until 7 AM EDT this morning for MDZ016-
     018.
     Coastal Flood Advisory until noon EDT today for MDZ011.
     Coastal Flood Advisory until 9 AM EDT this morning for MDZ014.
     Coastal Flood Warning until 6 AM EDT early this morning for
     MDZ017.
VA...Coastal Flood Advisory until 7 AM EDT this morning for VAZ057.
     Coastal Flood Advisory until noon EDT today for VAZ054.
WV...None.
MARINE...None.

&&

$$
SYNOPSIS...BJL/LFR
NEAR TERM...RCM
SHORT TERM...RCM
LONG TERM...LFR
AVIATION...RCM/LFR
MARINE...RCM
TIDES/COASTAL FLOODING...LFR


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