194
FXUS61 KLWX 010750
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
350 AM EDT Mon Sep 1 2025

.SYNOPSIS...
High pressure will slowly drift north and northeast of the area
through Wednesday. A pair of cold fronts will cross the area
late Thursday and Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure is centered across the Great Lakes this morning.
An upper low is centered near the Delmarva Peninsula. Another
chilly start to the day is underway. Similar to previous
mornings, there seems to be enough dry air in place the fog
development is limited to a few river valleys and low spots.

A fairly robust cumulus field should develop today beneath the
upper low. A few models even try to squeeze out a few sprinkles
or showers, but think the moisture depth is too shallow for this
to be worthy of a forecast mention. The gradient between the
high and broad low pressure off the southeast coast may result
in some northeasterly gusts of 15-20 mph. Highs should be
similar to yesterday in the mid 70s to around 80 (60s in the
higher elevations).

The high slides toward New England tonight. Mostly clear skies
should prevail with light winds. Dew points start to inch
upward, which may allow for more fog to develop, though it
should still be somewhat patchy near river valleys. Temperatures
should likewise be slightly higher, with 40s limited more toward
the mountains.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The upper low opens and/or lifts to northeast Tuesday while the
surface high continues to spread along the east coast. A mix of
sun and clouds can be expected beneath the upper trough but no
rain is forecast. Overall temperatures remain near persistence,
though Tuesday night lows may tick up in some areas in response
to moderating dew points.

The surface high should remain in control Wednesday but wind
direction will switch to southerly as its positions continues to
shift eastward. This will allow for continued slow moderation of
temperatures and dew points, with more locations potentially
topping 80. Warm/moisture advection will be more pronounced
across the mountains, and a lead shortwave trough may cross the
area. Thus, a few showers or thunderstorms may develop west of
I-81, but most areas will likely remain dry with partly sunny
skies. A deepening trough continues its approach from the
northwest Wednesday night, so can`t rule out a few showers,
mainly along the Allegheny Front. It will be a bit milder as
lows only drop into the mid 50s to lower 60s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Longwave trough will persist across the East into the second week of
September with several shortwave-troughs rotating around and
reinforcing the longwave trough pattern. A pair of cold fronts are
expected to move across the area during the second half of the week,
a weak front late Thu night/early Fri and a second, much stronger
one Sat night.

Showers and possible thunderstorms will begin to move into the
mountains Thu afternoon. Frontal convergence is expected to weaken
with time Thu night with most of the shower/t-storm activity
remaining west of Route 15. It`s uncertain how much moisture the
second front will have with it before it clears the area early
Sunday. High pressure will build into the area to start the
second week of September.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
High pressure maintains dry weather through Tuesday. A tighter
pressure gradient may result in some northeasterly wind gusts of
15-20 kt today. A cumulus field should also develop beneath an
upper low, perhaps becoming broken at times, though bases should
likely be at least 6kft. A slight increase in low level moisture
tonight may result in a slightly higher chance of patchy fog
near CHO and MRB, though dense fog appears unlikely. Winds will
be lighter Tuesday, but otherwise a persistence forecast
prevails. VFR conditions continue Wednesday but winds flip to
southerly as the high moves east.

Showers and a few thunderstorms are possible late Thursday
afternoon into Thursday night as a front approaches. Southerly
wind gusts to 20 kt are possible Thursday afternoon as well.
Lower chances for significant weather Friday in between systems.

&&

.MARINE...
Northeasterly winds should begin increasing near the southern
Maryland waters over the next few hours due to an increasing
gradient between high pressure to the north and low pressure off
the southeast coast. Models indicate some stronger gusts may
spread farther north later in the morning. However, it appears
the duration might only be 2-3 hours, so am thinking this can be
covered by a statement if it occurs. Also have not extended the
end time of the advisory as winds appear to decrease heading
into the afternoon, although some stray 20 kt gusts could
continue into the evening. A few models also show an uptick in
winds on the wider waters of the bay late tonight/Tuesday
morning, but believe the winds should largely remain below
advisory levels.

Winds will remain below advisory levels on Tuesday as high
pressure weakens overhead. As the high shifts eastward
Wednesday, winds will flip to southerly. Channeling could result
in advisory conditions along the bay by Wednesday evening.

SCA conditions are possible Thu and Fri preceding a weak frontal
passage.

&&

.TIDES/COASTAL FLOODING...
Water levels may fluctuate a bit through Tuesday as
northeasterly to easterly winds fluctuate in strength. Annapolis
may come close to reaching minor flood stage by tonight`s and
Tuesday night`s high tide, but confidence is low. A flip to
southerly flow Wednesday should allow for further rises in water
levels. Confidence in Annapolis reaching minor flood increases
Wednesday night. Peak water anomalies appear to occur Thursday
night ahead of a front. More locations may reach minor flood,
and some guidance has Annapolis approaching moderate flood.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ534-537-543.

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...ADS
LONG TERM...LFR
AVIATION...ADS/LFR
MARINE...ADS/LFR
TIDES/COASTAL FLOODING...ADS