Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 141906

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
206 PM EST Tue Nov 14 2017

.SYNOPSIS...High pressure will remain over the area through
Wednesday. A weak cold front will move across the area early
Thursday. High pressure will return briefly Thursday night into
Friday before a strong cold front moves through during the first
half of the weekend.


.NEAR TERM /THROUGH TONIGHT/...Low clouds have been stubborn
today under sfc wedge and strong subsidence inversion. Some
holes in the clouds have developed recently over northern VA,
but these are likely to fill in again as more low clouds are
seen moving southward from PA. Guidance indicate that clouds
will finally break out sometime tonight, but my confidence level
on this not particularly high given poor performance by models
today handling low clouds. Assuming at least the models have the
right trend on clouds decreasing tonight, expect at least some
partial clearing, but some guidance indicate a marine layer
advecting late tonight or around daybreak. Lows tonight in the
mid 30s.



The day should start out clear west of I-95 with a marine layer
advecting inland. Dense high clouds will also spread rapidly
ewd through the day with skies likely to become overcast by
early afternoon. Rain showers will move in after 7PM in the
highlands and push east but are likely to dry out as they reach
I-95. Weak cold front will cross the area around 12Z Thu with
drying conditions and breezy conditions developing. Warmer on
Thu due to strong downslope flow.



High pressure system will keep dry conditions on
Friday into Friday night with light winds over our area.

A strong low pressure system will move northeast over the Great
Lakes as its associated cold front pushes east over our area
sometime on Saturday. The timing of the front passage is still
uncertain, but deterministic and ensemble guidance suggests showers
-that could be heavy at times- are likely Saturday afternoon into
the night. Breezy conditions are expected behind the front in a cold
air advection regime. Some upslope snow showers are possible
Saturday into Sunday.

A high pressure builds behind this front Sunday into Tuesday with
returning dry conditions.



Ovc cigs 050 through early this evening, then clearing or
partial clearing. A marine layer could affect MTN and BWI late
tonight and early Thu. Sct showers expected Wed night with
fropa. Gusty NW winds expected Thu behind fropa.

VFR conditions expected Friday. Precipitation
possible Saturday as a strong cold front moves trough our area.
Dry/VFR conditions return on Sunday.


.MARINE...Winds will continue to diminish through Wed evening
then strengthen late Wed night and Thu behind fropa. Solid SCA
conditions expected Thu into Fri morning.

Winds are expected to stay below threshold on Friday into
Friday night. Winds will increase on Saturday and remain breezy
into Sunday, therefore, a small craft advisory is anticipated
Saturday into Sunday.




MARINE...IMR/LFR is the U.S. government's official web portal to all federal, state and local government web resources and services.