Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 231910
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
310 PM EDT Wed May 23 2018

.SYNOPSIS...
High pressure will build into the region from the northwest
late this afternoon through Thursday night. This high should move
offshore Friday. Moisture will increase ahead of a low pressure
system over the weekend into early next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
A shower in spots across southern Maryland, the central
Chesapeake Bay, or parts of the Virginia Piedmont is possible as
the cold front pushes across these areas later this afternoon.
A rumble of thunder cannot be ruled out. Any activity should be
very isolated and brief. High temperatures will be in the lower
to middle 80s for most locations.

High pressure will build in from the northwest tonight. Dry
conditions with mainly scattered mid-level clouds expected tonight.
Low temperatures will drop down into the upper 50s to near 60 over
the eastern half of our region, while lows should reach the lower
50s over the western half of our region.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
The center of high pressure will move overhead later in the day
Thursday into Thursday night before moving offshore Friday. In the
meantime, we can enjoy dry conditions Thursday into Friday.
As we get into late Friday and Friday night and looking out west
into the Potomac Highlands, we could encounter a shower or
two; otherwise, dry conditions for all.

Dewpoint temperatures will be in the lower 50s Thursday versus the
lower 60s that we experienced this afternoon. This should make
conditions a little more comfortable. Temperatures both Thursday and
Friday will reach the lower to middle 80s with increasing humidity
expected Friday around the back side of the area of high pressure.
Low temperatures Thursday night expected to be in the middle 50s to
upper 50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Saturday into Sunday, a high pressure system will be located off the
Atlantic coast near Bermuda. This will lead to a south to
southwesterly flow which will work to funnel tropical moisture
into the region. Temperatures rising up into the mid to upper
80s on Saturday and Sunday coupled with tropical moisture could
lead to the formation of convective showers and thunderstorms
which may produce heavy showers.

Monday through Tuesday, a weak boundary will approach from the west.
A south to southwesterly flow will continue the flow of tropical
moisture into the region. High temperatures will be in the low to
mid 80s on Monday. The approaching frontal boundary on Monday will
act as a convergence zone which may allow for some forcing to cause
the formation of storms and showers. The combination of tropical
moisture and the boundary will lead to a chance for thunderstorms
and showers on Monday.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions late this afternoon through Friday night. Winds
have become northwesterly and gusting over 20 knots at times behind
the cold front at all terminals, except for CHO, where winds are
generally still light out of the north. Expect winds to diminish
tonight as high pressure builds in over the region.

Saturday, the combination of tropical moisture and rising
temperatures up into the mid 80s will lead to an environment that
could be conducive for the formation of disorganize thunderstorms
and heavy showers.

&&

.MARINE...
A small craft advisory is in effect through late this afternoon as
we look at a cold front passing over the waters of the Potomac River
and Chesapeake Bay. For the most part, wind gusts have been between
17 and 22 knots with gusts as high as 26 knots in a few locations.

High pressure will build across the waters tonight and Thursday
before moving offshore on Friday with light winds. Some of the
wider waters of the Bay may come close to SCA criteria Friday
night as southerly flow increases on the back side of the high.

On Friday, winds will be out of the south which may lead to the
need for a small craft advisory. Skies should remain most clear with
mild temperatures in the upper 70s to lower 80s. On Saturday, the
influx of tropical moisture will combine with higher
temperatures to allow for the formation of disorganized showers
and thunderstorms.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies will continue to decrease this afternoon as
northwesterly winds develop behind a cold front. However, water
levels remain more elevated around DC given some freshwater
input, with the current high tide barely coming in below flood
stage. This situation may repeat itself during the morning high
tides the next couple days.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for
     ANZ530>543.

&&

$$
SYNOPSIS...KLW
NEAR TERM...KLW
SHORT TERM...KLW
LONG TERM...JMG
AVIATION...KLW/JMG
MARINE...KLW/JMG
TIDES/COASTAL FLOODING...KLW


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