Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 191430
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1030 AM EDT Sun Mar 19 2017

.SYNOPSIS...
High pressure will build over the area today and tonight,
before a cold front crosses the area Monday night. Strong high
pressure then builds across the region during the middle to
latter part of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 10am, snow has pushed south of the area. Accumulations are
in PNSLWX and with about 300 feet elevation being the
discriminator between trace (or just rain near sea level) and a
measurable amount.

Clearing is spreading in from the NE with low/mid level clouds
across the rest of the CWA per GOES imagery. Lowered hourly
temps for the central/western CWA through midday. A decent
amount of sunshine is expected this afternoon, so no change to
the MaxT as of this time.

High pressure then builds overhead tonight with clearing
expected by daybreak Monday. Chilly with temps in the low 30s
east and upper 20s west.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
High pressure will then shift rapidly to the south with showers
expected in the afternoon and night as cdfnt crosses the area.
Low pressure developing along front across North Carolina Tue
night will bring another round of rain Tue evening with rain
ending by daybreak Wed. Some accumulating snow is likely across
the higher elevs of eastern WV and Highland county.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Computer model guidance is in good agreement through Friday. By
Wednesday morning, the precipitation should be over as the area
of low pressure moves offshore. A secondary, but dry, front
will push southward during the day as an upper level trough axis
swings through the northeastern states. Colder air will rush
into the area with below normal temperatures expected.

Surface high pressure will build over the central Appalachians by
12Z Thursday, and favorable radiational cooling will result in
lower 20s in outlying areas. Temperatures will moderate slightly for
Thursday. The surface high will move offshore Friday while upper
level ridging builds overhead. There will be some additional cloud
cover due to warm advection aloft, but it will likely stay dry with
milder temperatures.

Guidance spread begins to increase Saturday as a low pressure center
moves into the Great Lakes and drags a cold front toward the area. A
faster solution (such as the GFS) would result in showers for
Saturday. Unless the front moves through early in the day though,
high temperatures could push 70F.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
MVFR conds improve to VFR through noon with NNWly flow gusting
around 20 knots through the afternoon.
Next chance of rain is Mon afternoon and night with next
frontal passage.

VFR conditions expected Wednesday and Thursday as high pressure
builds into the area. NW winds could gust to 25 kt Wednesday, with
lighter winds by Thursday.

&&

.MARINE...
SCA conditions today in Nly flow gusting 20 to 25 knots, then
winds begin to diminish this evening. Possible SCA again Tue
night.

Secondary cold front passage on Thursday will result in gusty NW
winds with SCA conditions possible. Winds will diminish heading
into Thursday as high pressure builds overhead.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ530-
     531-535-536-538-539-542.
     Small Craft Advisory until 6 AM EDT Monday for ANZ532>534-537-
     540-541-543.

&&

$$
SYNOPSIS...BAJ/LFR
NEAR TERM...BAJ/LFR
SHORT TERM...LFR
LONG TERM...ADS
AVIATION...BAJ/ADS/LFR
MARINE...BAJ/ADS/LFR



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