739
FXUS61 KLWX 220733
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
333 AM EDT Fri Aug 22 2025

.SYNOPSIS...
Weak high pressure will build in from the north today into
Saturday. Dry conditions continue through Saturday with another
cold front set to cross the area Sunday into Monday. A strong
dome of Canadian high pressure builds thereafter for much of
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Latest microphysics imagery shows clouds continuing west of
I-95. With dry air advection expected to persist through
daybreak in the wake of Erin, some erosion of this cloud deck is
expected. Clouds will hang on the longest west of US-15/the
Blue Ridge. Some fog is possible especially in the river valleys
although confidence in widespread fog is low especially west of
the metros given the residual cloud cover. Low temperatures are
forecast to be in the upper 50s to mid 60s.

Weak high pressure will build in through the day today. In turn,
this will result in much more sunshine than the past couple of
days and get us out of the "May Gray" pattern. Dry advection
will continue with a notable drop in dewpoints. Temps will
still be a few ticks below climo norms, with low to mid 80s
expected for most (cooler in mtns).

Expect a decent radiational cooling setup Friday night with
clear skies and light winds. This will result in low
temperatures in the upper 50s and low 60s across much of the
region outside of the immediate Washington DC/Baltimore metro
centers. Some sheltered river valley locations especially west
of the Blue Ridge could dip as low as the upper 40s and low to
mid 50s.

The focus through the weekend will be the continuation of
coastal flooding along the western shore of the Chesapeake Bay
and up across the tidal Potomac, especially during high tide.
For those traveling to the Delmarva beaches, be aware of
continued tidal flooding and rip current concerns which will
likely last through the weekend.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Aforementioned area of weak high pressure will drift eastward
Saturday as UL trough approaches from the west. Winds turn more
southerly with high moving offshore, which will result in a
moisture return across the area. Cannot rule out a few showers
and thunderstorms across the Alleghenies Saturday afternoon
given the proximity to the approaching trough/frontal boundary.
Highs Saturday will push back into the upper 70s and low 80s.
Lows Saturday night will fall back into the mid to upper 60s
with upper 50s and low 60s west of the Blue Ridge, More
widespread rain chances look to hold off til Sunday.

An upper low over southern Ontario on Sunday will dig across the
Great Lakes and northern mid-Atlantic early next week pushing a
strong cold front through the area Sunday. Showers and
thunderstorms, possibly severe, are expected Sunday into Sunday
night before the coldfront moves eastward. WPC has introduced a
MRGL ERO for areas general west of US-15 where the signal for
higher QPF around an inch or so exists (locally higher in
storms).

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A cold front and any lingering showers will move off to the east
early Monday. A series of mid-level disturbances will rotate
about a longwave trough of low pressure in the upper levels, but
only to bring additional clouds to parts of the region each day
into the latter part of the week. Otherwise, an area of high
pressure at the surface should win out and bring dry conditions
each day to nearly all of the region. The takeaway about next
week will be below average temperatures each day Monday through
Thursday.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
Once clouds break over airfields this morning, VFR conditions
are expected as high pressure builds into the region. This will
lead to decreasing winds out of the north at 5-10 kts. VFR
conditions will likely continue into Saturday as high pressure
pushes east of the region. Winds will turn back to the south
gusting between 10-15 kts Saturday.

Winds remain southerly Sunday ahead of cold front. Restrictions
possible in any showers/thunderstorms Sunday afternoon. Will
finetune timing over next couple forecast cycles.

VFR conditions Monday through Tuesday night. Winds generally
northwest 5 to 15 knots Monday through Tuesday night.

&&

.MARINE...
Winds will remain elevated through this morning. Small Craft
Advisories will continue through mid-morning, though latest
trends in wind field over the Chesapeake may allow for this to
be expired early. Winds should lessen for the entirety of the
bay/tidal Potomac as weak high pressure builds in from the north
and settles over the region today. Winds will remain out of the
north at less than 15 kts. The high eventually weakens further
while shifting offshore Saturday. This will allow the winds to
switch back to the south and for channeling to occur. Southerly
winds will gusts to around 15 to 20 kts Saturday afternoon. This
may lead to a period of SCA conditions over the middle and
lower waters Saturday afternoon and evening.

Sub-SCA level winds are expected Sunday with southerly winds
ahead of the front. and Monday. SMWs may potentially be needed
as thunderstorms pass over the waters Sunday afternoon into
Sunday evening.

No marine hazards Monday through Tuesday night. Winds northwest 10
to 15 knots Monday through Tuesday night.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies will remain elevated through the weekend ahead of
the next cold front.

Main update to the tidal forecast was to expand advisories to
other locations expected to hit minor flood stage and run it
through the end of the event Sunday given multiple high tides
are expected to hit minor if not moderate flood stage. Have
maintained the Coastal Flood Watch for Anne Arundel/Annapolis.
Will let day shift upgrade if anomalies stay course.

As winds slacken tonight into Saturday, a snap-back event is
expected to occur raising water levels further. Moderate coastal
flooding is likely at Annapolis and widespread minor coastal
flooding elsewhere (i.e DC Waterfront. Alexandria, Baltimore,
and Havre de Grace). Water levels likely remain elevated until
the cold frontal passage that comes in early Monday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 3 AM EDT early this morning for
     MDZ008.
     Coastal Flood Advisory until 2 AM EDT Saturday for MDZ014.
     Coastal Flood Watch from late tonight through Saturday morning
     for MDZ014.
     Coastal Flood Advisory until 7 AM EDT Sunday for MDZ016.
     Coastal Flood Advisory until 7 AM EDT Sunday for MDZ018.
VA...Coastal Flood Advisory until 7 AM EDT Sunday for VAZ057.
WV...None.
MARINE...Small Craft Advisory until 6 AM EDT early this
 morning for ANZ534-537-543.

&&

$$

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