740 
FXUS61 KLWX 051948
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
248 PM EST Sun Mar 5 2017

.SYNOPSIS...
High pressure remains in control of the weather today before moving
offshore Monday. A cold front crosses the Mid Atlantic Tuesday. Another
reinforcing cold front will pass through the area Wednesday into Wednesday
night. The front will then stall near the area into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Cold/dry ~1040 hPa dome of high pressure currently situated over the
area with lots of sun...as visible satellite imagery indicates nary
a cloud in the sky (except for a few dissipating amalgamated contrails
tracking eastward into our area from time to time). Clear skies combined
with light winds will promote radiational cooling again tonight. Though,
surface high shifting to the southeast will allowing a southerly wind
component to develop overnight. This will act to increase dewpoints
and will keep temperatures from falling too far. Despite this, expect
another night with lows below freezing across the entire area (M/U20s
in most spots).

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Warm up begins in earnest Monday as warm air advection continues with
southerly wind component. Warm front lifts into the area during the
day...and will provide a dividing line between U40s across northern
MD and U50s across central VA (M50s across northern VA). While 
temperatures will be 10-20 F above todays highs...they will actually
be near seasonable averages. Possibility of warm air advection 
showers near frontal boundary begins across the Allegheny Front 
Monday afternoon...with low-end chances extending into the I95 
corridor Monday night into Tuesday morning. 

Temperatures warm well into the 60s Monday as warm air advection
strengthens with breezy southerly winds ahead of approaching 
cold front. Better chances for precipitation across the entire 
area arrives Tuesday afternoon through early Wednesday morning 
as cold front crosses the area. Overall amounts through Wednesday
morning appear relatively light...but much needed...(generally 
a quarter to three quarters of an inch). Greatest amounts expected
along the higher terrain west of the Blue Ridge. 

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A cold front is forecast to be moving offshore to the east of the 
region Wednesday morning. There is not as good of a direct Polar 
connection following this front, and as such downsloping flow 
coupled with a partly to mostly sunny sky should result in mild 
temperatures similar to Tuesday. Wind trajectories are not quite 
ideal for upslope, nor are the temperatures so any precipitation 
would likely be a light and sporadic rain/snow shower mix over the 
western slopes briefly during the morning hours as the upper trough 
pivots across.

High pressure quickly passes by just to the south Thursday resulting 
in slightly cooler temperatures (though still a few degrees above 
normal). Another quick moving area of low pressure will likely pass
just north of the area, but its fast west to east motion suggests
limited moisture return and probably scattered showers at best.

Dueling areas of high pressure will set up over the eastern U.S. by 
week's end, with one a source of cooler air to the north and the 
other a source of warmer air to the south. Where exactly the frontal 
zone sets up between the two in the wake of the late week system 
will determine the temperature/precipitation outcome of the next 
area of low pressure slated to pass near the region during the 
second half of next weekend. There is very large ensemble spread not 
only in the evolution of the low pressure area next weekend, but 
also the wave pattern over the entire Northern Hemisphere which 
makes the forecast quite uncertain this far out.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...

VFR condtions expected through most of Monday. Low potential for
sub-VFR conditions in light showers beginning tomorrow afternoon
at MRB and then extending into other terminals Monday night. Better
chance for periods of sub-VFR Tuesday afternoon into Wednesday as
showers associated with cold front move eastward across the area.

Mainly VFR expected Wed-Thu w/ WLY flow around 10 kts.

&&

.MARINE...
Light winds across the waters today into tonight. Southerly
winds increase tomorrow (especially in the afternoon with best
mixing)...though gusts currently expected to remain below 18 
knots. Low-level wind field strengthens Monday night...unclear 
how much mixing will occur during the overnight period...so held
off on a SCA. Solid SCA conditions become likely Tuesday (once 
mixing increases after sunrise)...as low level flow strengthens 
further ahead of approaching cold front. There is some potential
for low-end gales as low-level wind field is quite strong...though
confidence is low at the moment. SCA wind gusts continue into 
Tuesday night...though gusts will begin to decrease late Tuesday
night.

SCA gusts likely linger in the wake of a departing front early 
Wednesday. A brief respite in wind gusts should cross the waters
as high pressure passes nearby late Wednesday into early Thursday
resulting in sub-SCA conditions. SCA gusts are possible again 
ahead of the next system by late Thursday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...DFH
AVIATION...MSE/DFH
MARINE...MSE/DFH