Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 222208

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
608 PM EDT Sat Oct 22 2016

Surface high pressure will build south of the area through the
remainder of the weekend as low pressure pulls lifts north from
New England. A reinforcing cold front will move through Monday
with cool high pressure to follow for mid week. A low pressure
system will approach from the west late in the week.


Was able to drop the wind advisory per observations. It will
remain quite gusty into the overnight as the pressure gradient
remains high. However, cold air advection is tapering off at 850mb
and 925mb per GFS/ECMWF, so gusts should continue to slowly

Radar trend is for a continued eastward shift in the plume off
Lake Erie with further sprinkles most likely KHGR and east.

Min temps around 40F inland, mid 30s near shore. Low 30s limited
to the highest ridgelines, not of any known agricultural
significance, so no freeze warning tonight.


Main trough axis lifts to the northwest for Sunday and Sunday
night which will allow for dry weather. Since we will still be in
the gradient with low pressure to the NE and high pressure to the
SW, it will still be breezy with 20-35 MPH gusts during the day.
Under weak warm advection, temperatures should recover 5-8

A reinforcing cold front will drop south into the area on Monday.
It will be moisture starved though, with only a small chance of
showers in the highlands. High temperatures will depend on the
timing of frontal passage, with southern areas standing the best
chance to see highs reach the 70+. The wind will still be
noticeable as well with gusts of 20-30 MPH. High pressure will
build from the west Monday night with lows returning to the 30s
and 40s.


Long term starts out with a big closed low over Atlantic Canada and
fast northwest flow on its southwestern flank over our region. This
low will very slowly shift east out into the Atlantic so that by
early Thursday a weak ridge is located over our region. This will
quickly be followed by a sharp trough which will move in Thursday
night. After that uncertainty grows with some guidance pushing the
shortwave through but leaving the longwave trough in place...while
other guidance cuts off a deep low over the region aloft.

For our sensible weather at the surface, this translates to high
pressure slowly building in with diminishing northwest winds
Tuesday. While the surface high doesn`t build directly overhead, it
will be close enough such that we could have a good radiational
night on Tuesday night, perhaps enough to bring frost into suburbs
again. High pressure remains to our north influencing our weather on
Wednesday into Wednesday night, but by Thursday, the next surface
low pressure will be approaching from the west with increasing
clouds and rain chances. Depending on the progress of the system,
the rain may continue into Friday or even Friday night, or end
fairly quickly. This is still pretty uncertain.

Overall, temps will stay below normal, with the coolest period
likely Tuesday with a little warming possible just ahead of the
front on Thursday.


VFR conds continue into midweek. NW gusts to 30 kt into this
evening, slowly easing overnight. Westerly gusts of 20-30 kt are
expected on Sunday. Otherwise, only some cumulus clouds around

A cold front will pass through Monday, with winds becoming NW
again with gusts 20-25 kt.

VFR overall Tuesday through Wednesday night outside of any early
morning fog, which would mainly CHO/MRB/IAD. Sub-VFR cigs/vis
possible Thursday on as a storm system brings rain back to the


NW gales extended until 8pm for far northern MD waters and allowed
to drop for the middle/upper tidal potomac where an SCA is in
effect. Gales drop at 2am for remaining waters and SCA for all
waters through Sunday with 25 kt gusts expected. SCA for at least
portions of the waters then Monday/Monday night.

Overall looking like winds will diminish through Tuesday with sub-
SCA likely by Tuesday night. Southerly channeling could bring
winds back to SCA levels Wednesday night or Thursday, but this is
still highly uncertain.


MARINE...Small Craft Advisory from 2 AM Sunday to 6 AM EDT Monday for
     Gale Warning until 2 AM EDT Sunday for ANZ531>534-537-539>541-
     Small Craft Advisory until 6 AM EDT Monday for ANZ530-538.
     Gale Warning until 8 PM EDT this evening for ANZ530-538.
     Small Craft Advisory until 6 AM EDT Monday for ANZ542.
     Gale Warning until 6 PM EDT this evening for ANZ535-536-542.
     Small Craft Advisory until 6 PM EDT Sunday for ANZ535-536.


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