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Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
943 am EST Thu Dec 8 2016

Synopsis...
cold front moves through the mid-Atlantic today. High pressure
returns to the area Friday into the weekend. Another cold front
crosses the area Monday followed by another reinforcing cold front
Wednesday.

&&

Near term /through tonight/...

Gusty winds up to 25 mph developing this afternoon. Highs peak in
the M/u40s...tumbling tonight behind cold front. Westerly flow
will promote the development of upslope snow showers overnight.

&&

Short term /Friday through Saturday night/...
on Friday mid-Atlantic will be sandwiched between Canadian high
pressure building into the area from the central Continental U.S. And trough
of low pressure departing the NE Continental U.S....with a strong cold air
advection pattern. Thus, expect a blustery and cold day...with
wind gusts up to 25-30 mph and highs at or below 40f. Additionally, wind
chills expected to be at or below freezing all day.

Strong low-level upslope component through a moist layer will allow
snow showers to continue Friday into Saturday morning. While low-end
advisory level snowfall remains possible...current forecast keeps
storm total amounts between 2-3 inches for the entire event (roughly
24 hours).

High pressure continues to build overhead Friday night through
Saturday night...with cold weather continuing. Lows Saturday and
Sunday morning at or below 30f. Highs Saturday similar to Friday...with most
places at or below 40f...though winds expected to be lighter as high
pressure is overhead by afternoon.

&&

Long term /Sunday through Wednesday/...
the long term is a bit active, continuing the recent trend started
at the end of November. Starting on Sunday, we have a fast zonal
flow aloft. We'll have a stationary front in the area with perhaps
a little overruning precipitation, most likely north of the County Warning Area.
Any precipitation that makes it into the County Warning Area may be wintry, at
least partly, given a cold atmosphere, but a lot of uncertainty on
this. Highs will be chilly, 30s north and 40s further south.

The fast zonal flow aloft buckles just slightly as a shortwave
moves across the region later on Monday. At the surface, a wave of
low pressure will ride across the area, but it looks like it will
cross to our north. While the odds of wintry precipitation will
still exist Sunday night, by Monday it appears the low pushes a
warm front north of the area and most of our County Warning Area will likely end
up rain. Highs will rise into the 40s to lower 50s. After a short
break Monday night into Tuesday, another disturbance is progged to
move late Tuesday and Wednesday next week. By this time however,
guidance gets into some significant disagreement, with varying
strength of the next trough. GFS has a signficant storm, though we
stay on the warm side until it passes, while ec is much weaker
with little precip. Either way, we end up cold late next week, but
temps middle of next week are highly uncertain.

&&

Aviation /15z Thursday through Monday/...
VFR conditions tonight with light flow. A cold front crosses the
area from the west. Gusty northwest winds expected this afternoon
through Friday...along with the possibility of some low level
turbulence.

VFR conditions prevail Saturday through Saturday night...with
relatively light winds as high pressure builds over the area. Sub
VFR possible Sunday night and Monday with another storm system
moving through.

&&

Marine...
a cold front moves through the waters later this morning with
west-northwest winds increasing to gusts up to 30 kt through the afternoon.
Small Craft Advisory begins at 10 am for most waters...and 2 PM for southern Maryland
waters. Small Craft Advisory then continues for all waters through Friday and will
likely need to be extended for at least a few hours Friday night
into Saturday morning. While a few isolated gale force wind gusts
are possible late tonight into Friday...most areas should just
have solid Small Craft Advisory conditions. Winds begin to diminish Saturday
morning as high pressure builds into the area.

Relatively light winds Saturday and Saturday night as high pressure
resides over the area. Winds may increase Sunday and Monday as
another system approaches.

&&

Tides/coastal flooding...

St. Mary's County has gone past the high tide cycle...ending minor
coastal flood threat for time being.

&&

Lwx watches/warnings/advisories...
District of Columbia...none.
Maryland...none.
Virginia...none.
WV...none.
Marine...Small Craft Advisory until 6 PM EST Friday for anz530>533-535-
536-538>541.
Small Craft Advisory from 2 PM this afternoon to 6 PM EST
Friday for anz534-537-542-543.

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