269
FXUS61 KLWX 010800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Thu Oct 1 2026

.WHAT HAS CHANGED...
Patchy fog is developing this morning. Timing and coverage of
rain continue to subtly shift through the weekend.

&&

.KEY MESSAGES...
- 1) After patchy morning fog, temperatures will remain above
  normal through Friday.

- 2) A stalling cold front may bring rain at times from Friday
  through Sunday.

- 3) Cooler and drier weather early next week with potential for
  frost and freeze west of the Blue Ridge Mountains.

&&

.DISCUSSION...
KEY MESSAGE 1...After patchy morning fog, temperatures will
remain above normal through Friday.

A shortwave trough is passing from the eastern Great Lakes to
New England this morning. Only some high level clouds have been
affecting our area, but now the thickest cloud shield is
departing to the east. In its wake, some patchy fog is
developing, mainly in the typical valleys and other rural areas.
Some locally dense fog is possible, but it appears unlikely it
will become widespread.

An upper level ridge will build over the area today while
surface high pressure remains offshore. Temperatures will climb
further today, with most of the lower elevations reaching the
lower 80s. Increasing low level winds will prevent full
decoupling tonight, resulting in most locations remaining in the
60s for lows. Even with increasing high level clouds Friday,
another day with highs in the 80s is expected.


KEY MESSAGE 2...A stalling cold front may bring rain at times
from Friday through Sunday.

A cold front will approach from the northwest Friday afternoon,
eventually pushing south of the area Friday night. Showers will
likely reach western Maryland by midday, progresses
southeastward during the afternoon and into the night. Despite
the warm temperatures, poor lapse rates aloft will limit
instability, so few if any thunderstorms are expected. A
westerly component to the flow could also result in downslope
drying, and many models show showers becoming more scattered in
nature with eastward extent. Rainfall amounts with this round
will likely be less than a quarter inch for most locations.

Strong high pressure will pass north of the area Saturday while
the front stalls across the southeastern states. Southern stream
moisture will likely overrun the boundary fairly far to the
north, but there remains some uncertainty in the dividing line
between rain and no rain. Overall, Saturday probably has a
better chance of being dry with the high to the north. A wave of
low pressure will likely ride along the boundary Saturday night
into Sunday, and this may provide a higher chance of rain
spreading northward into the area. In a reversal of last night,
the latest guidance has shifted back northward with rainfall
coverage during this period. In the end, the details are far
from solidified. However, any rain that does occur will likely
exit the area Sunday evening.

Being north of the boundary and potentially having a lot of
cloud cover, high temperatures will likely remain in the 60s for
most areas over the weekend.


KEY MESSAGE 3...Cooler and drier weather early next week with
potential for frost and freeze west of the Blue Ridge Mountains.

A second stronger cold front associated with a deepening trof
south of James Bay will cross the area Monday morning. This
appears to be a dry frontal passage, and temperatures could
rebound back into the 70s as skies clear.

A large area of high pressure will build from the Upper Midwest and
Great Lakes to the Northeast and Mid-Atlantic in the wake of the
front. This will bring at least a few days of dry weather and
below normal temperatures. Highs will likely be in the 60s (50s
mountains), with lows in the 40s to near 50 (30s mountains).

As high pressure moves overhead Monday night through Tuesday night,
winds will be light and skies will be clear. Given the cooler air in
place during this time and the favorable setup for radiational
cooling, sheltered valleys and higher elevations near and west of
the Blue Ridge may be cold enough for frost formation. Some of the
typical cold sinks could drop to near freezing, as well. This is
roughly 1 to 2 weeks earlier than average.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Patchy fog is developing this morning, and has already been
affecting CHO and MRB. It appears unlikely the other terminals
are affected. Otherwise VFR conditions are expected into midday
Friday with light southerly winds.

A cold front will enter the area late Friday afternoon or
evening. Some showers are possible along the front, but they
will likely be fairly light. A brief period of MVFR conditions
is possible Friday night.

The front will stall to the south over the weekend, but its
position remains uncertain. Saturday has the greater chance of
being dry, with a wave of low pressure potentially bringing rain
on Sunday. Any sub-VFR conditions would likely be limited to CHO
Saturday, but could spread northward Sunday.

VFR conditions are expected to prevail Monday into Tuesday, though
some early morning river valley fog is possible. Winds will be north
with an increase for a time in the wake of the weekend system. The
timing is a bit uncertain, but favors late Monday or early Tuesday
when gusts of 20-25 kts are possible.

&&

.MARINE...
Southerly winds will uptick a little today into Friday. A Small
Craft Advisory may be needed on the wider waters of the middle
bay tonight into Friday morning, but confidence is lower since a
southwesterly component to the flow would limit channeling
effects. A cold front will push southward Friday night, with
advisories possible in the ensuing northerly flow through parts
of Saturday. After that, winds may be relatively lighter until a
second cold front pushes through on Monday.

Strong northerly winds in the wake of this front will likely
prompt SCAs Monday into Tuesday. A few gusts near gale force are
possible if the stronger solutions verify.

&&

.TIDES/COASTAL FLOODING...
Some uncertainty continues to exist through Friday as tide
levels remain elevated and subtly fluctuating. These small
changes will make the difference in whether there is additional
minor flooding. Alexandria, Dahlgren, Annapolis, and Havre de
Grace have the greatest chance of reaching flood stage, although
based on current trends, Annapolis has the highest chance. The
evening high tides are favored for any flooding since they are
astronomically higher. A cold frontal passage should lead to
declining water levels Friday night.

&&

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

&&

$$

DISCUSSION...ADS/DHOF
AVIATION...ADS/DHOF
MARINE...ADS/DHOF