Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 150737

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
337 AM EDT Fri Sep 15 2017

An area of high pressure will build into the region today through
Sunday. Tropical Storm Jose is forecast to move north as a
hurricane along...but well offshore of...the Atlantic coast
Monday into Tuesday. See the National Hurricane Center bulletins
for the latest information on Jose.


Low and mid-level clouds will continue to break apart overnight
through daybreak. With these clearing skies and low-level
moisture in place, areas of fog will develop in parts of our
region. As of 3am, places like Cumberland, Maryland and
Winchester, Virginia are showing signs of reduced visibility.
Other places should follow during the next few hours.
Visibility, for the most part, will be about 1 to 2 miles, but there
could be isolated spots that see less than one half mile by
daybreak. Reduce speed and use low beam headlights to use caution in
patchy or areas of fog. Low temperatures will reach the lower to
middle 60s.

Although the main upper level low, affiliated with the remnants of
Irma, will be over eastern portions of New England and high
pressure will be building into the region today, some leftover
energy from Irma could stay back over the area. We have just a
slight chance of a shower or two in parts of the region. Not
everyone will get a shower. Computer models are very diverse of the
locations that have this slight chance of showers. Highs today will
be in the lower 80s.

As any showers in the area dissipate this evening, skies will begin
to clear once again. These clearing skies and residual moisture
could play a role in introducing some patchy dense fog over much of
our region overnight tonight. Lows will bottom out only in the
middle 60s.


High pressure will rebuild across the region Saturday through Sunday
night. Once again, despite high pressure over much of the region,
some weak upper level energy could stretch across the region
and bring a slight chance of a shower to parts of the region.
For the most part, high pressure will provide a dry and
comfortable afternoon and evening, both Saturday and Sunday.
Highs in the lower to middle 80s Saturday with lows in the
middle 60s Saturday night. Highs lower 80s Sunday with lows
middle 60s Sunday night.


Model guidance consistent in forecasting a storm track for Jose that
is northbound off the east coast of the United States.  The official
NHC forecast maintains this multi-model consensus. (Consult the NHC
website for updates.) That said, it is important to note that track
forecast errors on days 4-5 average 150-200 NM respectively. So, it
would be premature to jump to any conclusions at this stage, but it
would be prudent to monitor the progress of this system. Forecast
will have low-end PoPs along the Bay along with 10-20 mph winds
Monday into Tuesday, representing the potential gradient that may
exist. On top of that, convergence and orographic lift may yield
scattered showers in the mountains each afternoon.

Wednesday into Thursday likely to be quieter as broad high pressure
regains control. This timing is subject to change though, based on
what pans out leading up to midweek. Stay tuned.


VFR conditions through daybreak. We can`t rule out MVFR or IFR
conditions based on visibility for any fog that develops near the
MRB and CHO terminals. Winds light and variable to perhaps calm.

VFR conditions at all terminals today. We can`t rule out a shower in
spots, but locations are uncertain. Nonetheless, the showers
shouldn`t affect ceilings or visibility to a restriction. Winds
northwest to north around 5 knots.

VFR conditions tonight. Some patchy or areas of fog could reduce
visibility, mainly near CHO and MRB. Winds northwest around 5 knots
or less.

VFR conditions Saturday and Saturday night at all terminals. Winds
becoming northeast around 5 knots Saturday, then light and
variable Saturday night.

The most likely scenario at this time yields VFR conditions across
the terminals Monday into Tuesday. The best bet for flight
restrictions will be early each morning due to predawn low clouds
and fog. All interests should monitor products from NHC for the
latest on Jose.


No marine hazards expected today through Saturday night. Winds
northwest 5 to 10 knots Friday and Friday night. Winds becoming
north to northeast around 10 knots Saturday, then easterly 5 to 10
knots Saturday night.

The pressure gradient will be increasing Monday into Tuesday as Jose
nears the Mid Atlantic coast. The potential for Small Craft
Advisory caliber winds exists, with a minimal but non-zero
probability of Tropical-Storm-Force winds.  All interests should
monitor products from NHC for the latest on Jose.


Water levels continue at one-half to three-quarters of a foot above
astronomical predictions. Many action stages are being reached, with
a couple mighty close to minor flood (eg: Annapolis). Will be
dropping the aforementioned Advisory, with no other Advisories
anticipated today. These trends likely to continue into the reaching action stage with the night time tide cycle,
which is the higher of the two astronomically.

By Sunday night-Monday morning, water levels may increase due to
increased onshore flow. These trends will be monitored.


MD...Coastal Flood Advisory until 5 AM EDT early this morning for


TIDES/COASTAL FLOODING...HTS is the U.S. government's official web portal to all federal, state and local government web resources and services.