431
FXUS61 KLWX 221852
AFDLWX

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

.SYNOPSIS...

Weak high pressure will continue to build in from the north
through Saturday bringing mostly sunny skies, near normal
temperatures, and lower humidity. Shower and thunderstorm
chances return with a cold front that is set to cross the area
Sunday into Monday. A strong dome of Canadian high pressure
builds thereafter with near to below normal temperatures for
much of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...

High pressure will continue to build into the region from the
north tonight with clear skies expected across northern areas,
except across western VA and eastern WV where low clouds are
expected to persist much of the night before dissipating
Saturday morning. Low temperatures will be around 60.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...

High pressure will shift further offshore Sat allowing winds to
to turn southerly allowing moisture to return into western
areas. Scattered showers and thunderstorms are possible across
the spine of the Appalachians Saturday afternoon and early
evening before dissipating overnight Saturday night.

A cold front will approach the area Sunday associated a digging
upper level trough/closed low across the Great Lks and northern
Mid- Atlantic. The best low-level forcing/sfc convergence along
the front will be located well north of the area over nrn PA
and western NY and the best moisture is expected to arrive late
Sunday night prior to frontal passage when instability should
be waning. Not sure how much thunderstorm coverage there will
be and also severity as instability looks marginal.

The cold front will exit the area early Monday after 06Z with
showers ending shortly thereafter.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...

A few lingering showers and perhaps a thunderstorm are possible
mainly east of the Blue Ridge Monday as the cold front slowly exits
the region. A large dome of Canadian high pressure will dominate the
forecast thereafter for much of the new work/school week. This high
pressure system will deliver an early tease to fall with
unseasonably cool temperatures (below normal) for late August into
early September. Dry conditions will also prevail outside of Monday
furthering the return or expansion of abnormally dry conditions
across portions of the area (mainly north of I-66/US-50 (see latest
drought monitor)).

Expect a slight bump in winds Monday as the front exits east and
high pressure builds from the Ohio River Valley. Gusts of 15 to 20
mph are possible out of the north and northwest before a quick
decrease Tuesday into midweek as the high settles overhead. Skies
will trend mostly sunny to partly cloudy throughout the week as
several weak mid level disturbances pivot through the longwave
trough nearby. The bigger story in the extended will be the
temperatures and humidity. Dewpoint values will hang out in the 40s
and 50s throughout much of the week with air temperatures running 5
to 10 degrees below average making for an early Fall feel. High
temperatures Tuesday and Wednesday will hang out in the mid to upper
70s with low to mid 60s across the mountains. Overnight lows will
sit in the upper 40s and low to mid 50s. The colder high valleys of
the Alleghenies could see a touch of fronts on Tuesday, Wednesday,
and Thursday mornings with lows in the 30s.

High pressure will gradually move out of the area by Friday with
another front approaching next weekend. This will bring the next
chance of showers and thunderstorms to the region.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...

VFR conditions are expected today as high pressure builds into the
region. This will lead to decreasing winds out of the north at 5 to
10 kts. VFR conditions will likely continue into Saturday as high
pressure pushes east of the region. Convective chances return for
terminals mainly west of MRB and SHD Saturday afternoon and evening
as another front/trough approach the region. Winds will turn back to
the south gusting between 10 to 15 kts. Additional showers are
possible for areas east of the MRB and southeast of DCA Saturday
night although confidence is low. This is in association with some
added moisture from an area of low pressure moving up along the
southeast U.S coast.

Prevailing VFR conditions are expected on Sunday and Monday,
although temporary drops to sub-VFR may be possible on Sunday
afternoon as scattered thunderstorms move through. Winds will be out
of the south on Sunday, and then out of the west to northwest on
Monday. VFR conditions are expected thereafter for much of next week
(Tuesday through Friday) as Canadian high pressure settles over the
region.

&&

.MARINE...

Weak high pressure will settle overhead tonight. High pressure
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 and evening. This may lead to a brief
period of SCA conditions over the middle and lower waters
Saturday afternoon and evening.

Sub-SCA level winds are expected on both Sunday and Monday. Winds
will be out of the south on Sunday, and then out of the west to
northwest on Monday. SMWs may potentially be needed as thunderstorms
pass over the waters Sunday afternoon into Sunday evening.

No marine hazards are expected for next week (Tuesday through
Friday) as high pressure settles over the waters.

&&

.TIDES/COASTAL FLOODING...

Tidal anomalies will remain elevated through the weekend ahead of
the next cold front.

A snap-back event occurred last night causing widespread minor
coastal flooding to tidal areas of the Potomac River and
Chesapeake Bay with borderline moderate coastal flooding at
Annapolis. Water levels will remain high as water will have no
place to go under light winds and then under southerly
channeling Sat afternoon-Sat night until strong cold front
crosses the area early Monday. For this reason, Coastal Flood
Advisories have been extended through the weekend. The worst
flooding will occur at Annapolis with the high tide at 610 AM
Saturday when the tide will be the highest of the next few days.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Coastal Flood Advisory from 6 PM this evening to 11 AM EDT
     Saturday for DCZ001.
MD...Coastal Flood Advisory until 6 AM EDT Monday for MDZ011-018-
     508.
     Coastal Flood Warning until 10 AM EDT Sunday for MDZ014.
     Coastal Flood Advisory until 7 PM EDT Sunday for MDZ016.
     Coastal Flood Advisory until 6 PM EDT Saturday for MDZ017.
VA...Coastal Flood Advisory until 7 PM EDT Sunday for VAZ054-057.
WV...None.
MARINE...None.

&&

$$

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