Area Forecast Discussion
Issued by NWS Sterling, VA

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869
FXUS61 KLWX 161903
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
303 PM EDT Thu May 16 2024

.SYNOPSIS...
Drier conditions are expected today through Friday as low pressure
slowly pushes off the Mid-Atlantic coast and weak high pressure
builds in. Increased shower and thunderstorm chances return this
weekend as another low pressure system pushes across the region.
High pressure briefly returns Monday and Tuesday ahead of a slow
moving cold front set to cross by the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As low pressure departs and weak ridging builds into the region,
mostly dry conditions are expected today. Fair weather cu is
visible on satellite over most of the region with denser cloud
cover over central and northeast Maryland as well as the
mountains to the west. A few showers with isolated thunderstorms
are possible near and west of the Blue Ridge this afternoon as a
weak boundary moves through before dissolving this evening. Dry
conditions are expected elsewhere with highs rising into the
70s. Clouds increase through the night ahead of an approaching
system and lows hover in the 50s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
On Friday, an upper trough and associated surface low will be
moving through the Great Lakes/Ohio Valley. A warm front lifts
into the area, acting as a focus for scattered shower and
thunderstorm activity by Friday afternoon, primarily along and
west of the Blue Ridge, before advancing eastward overnight.
There is potential for the warm front to stall nearby as the
attendant low moves off to the northeast. Light flow could mean
slower storm motions as well, so some isolated flooding is
possible. WPC currently has much of the area along/west of the
Blue Ridge outlined with a Marginal ERO.

Heading into Saturday, a stronger shortwave moves into the
southeast to pick up the stalled warm frontal boundary.
Continued shower and thunderstorm activity is expected through
day Saturday. Isolated flooding continues to be a concern with
repeated rounds of slow moving showers. Around 1-2 inches of
rain are expected through the duration of the weekend. Some
areas could see closer to 2.5 inches, but confidence on exactly
where is low as it depends on where the boundary will be Friday
night into Saturday. For now, highest estimates are in portions
of the Shenandoah Valley and Virginia Piedmont. Shower and
thunderstorm coverage decreases through Saturday evening as the
low moves off to the southeast, but rain likely continues into
Sunday.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Late in the weekend on Sunday, an area of low pressure
will be moving south of the region, allowing some showers to trickle
in across the southern half of the CWA. Highs on Sunday will be a
bit cooler compared to the previous days, with 60s being most common
across the area. Rain chances will continue to diminish by the late
evening hours. Fairly dry start to the workweek with high pressure
influencing the region. Highs on Monday will be in the low to mid
70s with overnight lows dropping down into the low 50s.

The next system approaches on Tuesday from the west, increasing
clouds, especially along and west of the Blue Ridge. Highs will
climb into the upper 70s to near 80. Cannot rule out a stray shower
overnight Tuesday in the aforementioned areas, otherwise mostly dry
conditions with lows in the mid 50s.

Fairly potent system approaches the area by Wednesday, with a cold
front advanced out ahead of the system. Guidance has been hinting at
the opportunity for increased instability ahead of the frontal
passage. Could see some thunderstorms develop, with some getting
strong to severe. Still a lot of uncertainty with this system with
respect to timing and intensity. Highs on Wednesday will be in the
upper 70s to low 80s.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR conditions continue this afternoon and through the early
evening. Overnight, ceilings lower with increasing cloud cover
ahead of an approaching system. MVFR conditions move in around
8z-10z and likely continue into mid-morning. Fog could be the
limiting factor rather than ceilings for CHO. IFR conditions are
possible for MRB and CHO, but confidence is low. Conditions look
to improve by Friday afternoon, but gradually deteriorate
through the evening. Sub-VFR conditions likely continue through
much of Saturday.

VFR conditions are expected Sunday into Monday with an isolated
chance for a shower, mainly near KCHO and points further south on
Sunday. Winds out of the northeast on Sunday will begin turning more
southeasterly later in the day on Monday.

&&

.MARINE...
SCAs continue through 10PM this evening with gusty N/NE flow.
Winds diminish overnight, turning S/SE on Friday. Winds increase
Saturday as low pressure passes to our south, likely
necessitating SCAs once more.

SCA conditions may be possible Sunday afternoon with a tighter
pressure gradient present over the waters. Better confidence in this
would be across the open waters of the lower Tidal Potomac and
central Chesapeake Bay. Northeasterly winds diminish Sunday night
and become light and southeasterly heading into Monday afternoon and
evening.

&&

.TIDES/COASTAL FLOODING...
Waters levels will gradually decrease today with north to
northeast flow behind departing low pressure.

Tidal anomalies will begin to rise again Friday and into the weekend
given a fairly prolonged period of east to southeasterly onshore
flow. A number of sites will return to Action stage, with the more
sensitive locations pushing into Minor. Elevated water levels likely
persist into Monday given little change in the overall wind
direction.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for
     ANZ530>543.

&&

$$

SYNOPSIS...EST
NEAR TERM...CAS
SHORT TERM...CAS
LONG TERM...ADM
AVIATION...ADM/CAS
MARINE...ADM/CAS
TIDES/COASTAL FLOODING...BRO