Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 241912
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
212 PM EST Tue Jan 24 2017

.SYNOPSIS...

Low pressure south of Long Island will continue to track to the
northeast. High pressure will build into the area this afternoon
through Wednesday. A cold front will pass through the area
Wednesday night. An upper level trough will move over the eastern
Canada for the end of the week and into the weekend. Another cold
front crosses the area late in the weekend.

&&

.NEAR TERM /TONIGHT/...

Mid Atlantic remains under influence of cyclonic flow as strong
low pressure is positioned south of Long Island. This is causing a
layer of stratocumulus over much of the forecast area. This will
be diminishing this evening. It should be clear after midnight.
Lows will be in the 30s..around 40 in the cities.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...

High pressure over the region Wednesday. Highs in the mid to upper
50s across the northern half of the region..and lower 60s south.
Highlands will be a little cooler with temperatures reaching the
lower 50s. This is about 15 degrees above normal for late Jan.

A cold front will be moving through the region Wednesday night,
bringing a chance for rain showers. Still, it will not be very
cold: lows in the 40s except for the colder Highlands.

And while this will be a cold frontal passage temperatures
Thursday will again not be that cold. Highs will be in the
50s...although temperatures could be falling during the afternoon.
Precipitation will be shutting down east of the mountains. In the
Highlands mixed precipitation will be possible during the day,
becoming all snow Thursday night. For now we`re thinking around 2"
will be possible - below advisory level (for the mountains), but
we`ll have to reevaluate this on later shifts.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...

West/northwesterly flow will persist over the region, with multiple
waves of energy moving across Friday into Sunday. Snow showers
expected over the Allegheny Front for what it looks like an extended
period of light snow showers... and mainly dry conditions expected
east of the mountains through the weekend.

Trough axis will deepen over the eastern CONUS on Sunday and push
eastward reaching the Mid-Atlantic Sunday night into Monday. It will
bring plenty of energy over the region, but still uncertain on
precipitation associated to it as guidance is on disagreement. If
any precipitation, expecting snow. Upper level ridge builds Monday
night into Tuesday bringing drier conditions with it.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...

Ceilings hovering around FL030 but cloud coverage will thin this
evening then VFR overnight and Wednesday. Shower activity Thursday
night could cause brief periods of MVFR ceilings.

Upper level disturbance will be affecting us during the weekend.
Winds will be breezy mainly Friday and Saturday. VFR conditions
expected.

&&

.MARINE...

Winds still in solid small craft as low pressure exits to the NE
and high pressure builds into the waters. Winds should diminish by
midnight then no problems overnight through Wednesday night.
Another SCA is likely Thursday afternoon and night.

Upper level disturbance will be affecting us during the weekend.
Winds will be breezy, mainly Friday and Saturday. Small craft
advisory probably needed parts of this period.

&&

.TIDES/COASTAL FLOODING...

Water levels remain elevated but are slowly dropping on northwest
winds in a tight pressure gradient water levels should drop.
Straits Point is just above minor flood but will be dropping as
the afernoon progresses.

Water level departures will continue to decrease through midweek.
Although there will be a brief window of return flow Wednesday,
speeds will be light and the current excess should be able to
evacuate from the estuary first. Otherwise, nothing but northwest
flow through the week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 AM EST Wednesday for ANZ531>534-
     537-539>541-543.
     Small Craft Advisory until 10 PM EST this evening for ANZ530-
     535-536-538-542.

&&

$$
PRODUCTS...WOODY!/IMR



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