667
FXUS61 KLWX 221414
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1014 AM EDT Sun Sep 22 2024

.SYNOPSIS...
A frontal system will stall over the area today. A strong front and
area of low pressure over the Great Lakes and Upper Midwest will
approach the area during the early or middle part of the week. High
pressure will follow mid to late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Ongoing low clouds and drizzle across the area. Ground fog has
lifted aside from the eastern slopes of the Alleghenies where
locally dense fog remains. Otherwise, previous discussion
follows...

A few showers are possible along the backdoor front today, but
with diminishing forcing aloft expect coverage to be isolated to
widely scattered. Low clouds to the east gradually eroding and
lifting this afternoon.

High temperatures will likely rise to around 80 F over the
valleys of eastern WV and western VA west of the backdoor front,
with areas further east staying in the low to mid 70s due to
increased cloud cover and onshore flow.

Low temperatures tonight will drop into the upper 50s to mid
60s. A few showers, drizzle, or fog are possible generally west
of US-15 in the vicinity of the stalling front tonight.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
The pattern doesn`t change much heading into Monday. Thus,
expect lingering cloud cover for much of the area along with
muted diurnal temperature spread.

Another trough and area of low pressure/frontal system begin to
approach from the OH Valley/Great Lakes by later Monday resulting in
increasing rain chances from west to east especially Monday
night. This system will gradually push across the area Tuesday
and Tuesday night with showers and a few thunderstorms likely.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A potent upper trough over the Midwest slowly moves eastward, with
an associated area of surface low pressure developing over the
central Great Lakes. A wet middle of the week is likely as at least
a few waves of low pressure aloft move across the Mid-Atlantic,
bringing periods of scattered showers and possibly a few
thunderstorms. The persistent CAD-like wedge at the surface remains
in place through at least Thursday, keeping low clouds and cooler
conditions in place, especially east of the Blue Ridge. Highs in the
middle to possibly upper 70s are expected each day, with overnight
lows in the 50s to low 60s. A weak cold front is progged to cross
the area sometime late Thursday, though model solutions diverge
greatly for the end of the week. This might not be enough to
scour out the cloud cover and moisture over the region. There
remains a lot of uncertainty with the forecast for the end of
the week into next weekend. Continue to monitor for updates as
we go through the week.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
Fog, dense at times, is anticipated at CHO and MRB through mid
morning. The metro terminals will likely see IFR CIGs lifting to
MVFR then gradually scattering out midday into this afternoon,
perhaps a bit earlier at MTN as a backdoor front pushes through.
Any early AM convection should wane around daybreak. Winds will
be E/NE 5-10 kts through tonight.

Onshore flow continues Monday into Tuesday with bouts of lower
CIGs and patchy fog (especially overnight) possible at times.
Showers and a few thunderstorms are possible late Monday through
Tuesday night.

Sub-VFR conditions are likely to continue through the end of
the week, with MVFR CIGs during the day, dropping to IFR at
night. Could see some fog develop, further adding to
restrictions at area terminals. Expect scattered showers at
times Wednesday into Thursday. Southeast winds around 10 knots
Wednesday become variable Thursday, though the forecast for the
end of the week becomes highly uncertain.

&&

.MARINE...
Onshore flow is expected through Tuesday night. Shower and
thunderstorm activity should diminish early this morning. A few
gusts of 15-20 kts are possible at times in the wake of a
backdoor front, though most of the time should be sub-SCA.

Southeast winds around 10-15 knots mid week become variable on
Thursday. Scattered showers are expected to move across the
waters each day through at least Thursday, though not expecting
any strong wind gusts at this time. Marine fog could develop
each night into morning over the waters.

&&

.TIDES/COASTAL FLOODING...
A very prolonged period of onshore flow (east to southeast)
will continue through much of the week. Minor coastal flooding
is likely at high tide at all sensitive locations for the next
few days. Coastal Flood Advisories are in effect for nearly the
entire western shoreline of the Chesapeake Bay and tidal Potomac
River, including Washington DC. A steady rise in anomalies is
expected to produce Moderate flooding at Annapolis through
tonight. As a result, a Coastal Flood Warning remains in effect.
Also, Washington DC SW Waterfront/Alexandria could approach
Moderate flooding. Expect headlines to be extended for much of
the upcoming week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Warning until 5 AM EDT Tuesday for DCZ001.
MD...Coastal Flood Warning until 5 AM EDT Tuesday for MDZ014.
     Coastal Flood Advisory until 5 AM EDT Tuesday for MDZ011-
     016>018-508.
VA...Coastal Flood Warning until 5 AM EDT Tuesday for VAZ054.
     Coastal Flood Advisory until 5 AM EDT Tuesday for VAZ057.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...DHOF
NEAR TERM...DHOF/CPB
SHORT TERM...DHOF
LONG TERM...KRR
AVIATION...DHOF/CPB/KRR
MARINE...DHOF/CPB/KRR
TIDES/COASTAL FLOODING...LWX