206
FXUS61 KLWX 211907
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
307 PM EDT Fri Aug 21 2026

.WHAT HAS CHANGED...

All sections were updated.


&&

.KEY MESSAGES...
- Wet conditions expected tonight and Saturday with improving
  weather Sunday.

- Dry conditions anticipated early next week.

&&

.DISCUSSION...

KEY MESSAGE 1...Wet conditions expected tonight and Saturday with
improving weather Sunday.

KEY MESSAGE 1 DESCRIPTION...

Low pressure is expected to organize across the southern Mid-
Atlantic tonight into Saturday as upper level energy digs across
the OH Valley. As this low begins to lift northeast tonight,
expect rain to develop across much of the area tonight into
Saturday with some decent rainfall totals expected south of the
Capital Beltway, particularly across St. Mary`s County where
most guidance show one to two inches of rain, possibly more. A
few WPC/NBM QPF members show enough rain in St. Mary`s County to
bring the St. Marys River at Great Mills into flood stage. The
steady rain will exit the area by late morning with a lull in
precip expected, although a low overcast is expected to persist.
By evening, another round of showers and thunderstorms will
approach the Appalachian Mountains and may make to areas east of
the Blue Ridge Mountains overnight Sat night into early Sunday.

By Sunday morning the cold front will be crossing the area with
dry air advection ensuing in strengthening NW winds. However,
there could still be enough moisture and lift to spark a few
showers, but overall drying conditions are expected throughout
the day.

KEY MESSAGE 2...Dry conditions anticipated early next week.

KEY MESSAGE 2 DESCRIPTION...

Behind an anticipated cold front, Monday brings drier and cooler
than average conditions. With a strong upper-level low moving
further into eastern Canada, subsidence increases in our region
as a surface high pressure system builds over West Virginia
well into Tuesday. This offers some potential relief from humid
conditions with dewpoints dropping into the 50s and 60s. On
Monday and Tuesday, we are expecting highs to remain in the low
70s to mid 80s.

As we head into late next week, an upper-level short wave moves into
the Great Lakes region, bringing increasing chances for
widespread lift across our forecast area. Depending on the
location of a surface low tracking along the Mid-Atlantic,
tropical moisture could reach as far north as Pennsylvania,
increasing chances for showers and thunderstorms through much of
Thursday. With PWATs above 1.5 inches, the hot and humid
conditions return late next week. Temperatures rise back into
late-August normals with highs in the 80s and 90s Thursday.

&&

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

Rain developing tonight with cigs gradually dropping into IFR
category by daybreak. Rain exits by Noon Saturday with IFR/MVFR
cigs persisting all day. Isolated thunderstorms also possible.
Conditions improving Saturday.

Light to gentle winds shift westerly on Monday and Tuesday. VFR
conditions are expected early next week.

&& BK BK SC
WDR  36 06 09 13 16 11 11 12 09 09 09 11 20 28 29 30 30 29

.MARINE...

Possible SCA conditions Saturday and again Sunday in NW winds.

Sub-SCA level conditions are expected Monday and Tuesday with gentle
winds out of the west/northwest. Chances for showers and
thunderstorms pick back up on Wednesday,making SMWs are
possible.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...LFR/KVH
AVIATION...LFR/KVH
MARINE...LFR/KVH