626
FXUS61 KLWX 040900
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EST Wed Mar 4 2026

.WHAT HAS CHANGED...
Patchy dense fog is possible this morning, especially in
northeastern Maryland. The frontal temperature gradient has
been a little better defined through Friday but remains highly
uncertain.

&&

.KEY MESSAGES...
- 1) A meandering front will bring highly variable temperatures,
  occasional rain chances, and potential for nightly fog
  through Friday.

- 2) A weak cold front arrives late Saturday and slowly pushes
  through by Sunday night before stalling nearby early next
  week.

&&

.DISCUSSION...
KEY MESSAGE 1...A meandering front will bring highly variable
temperatures, occasional rain chances, and potential for nightly
fog through Friday.

The front has snaked its way into northern parts of the forecast
area early this morning, which resulted in steady/rising
temperatures to its south and some clearing of the low clouds.
While some patchy fog could develop at times in this clearing,
it does appear abundant mid level cloudiness and passing showers
will help limit its spread. Northeastern Maryland is more
solidly in the saturated cool sector, and some locally dense
fog has developed there based on traffic cameras and the Harford
County Airport observation.

An expanse of showers has formed along the frontal zone across
the Ohio Valley. These showers have tended to weaken as they
cross the Appalachians in relatively blocked westerly flow.
Nevertheless, it appears off and on showers will rule the day,
especially for western and northern sections of the CWA. The
front is also forecast to sag back southward as a weak area of
high pressure passes by to the north. The progression of the
front and rain will play a role in temperatures today. Areas
closer to the Pennsylvania border will likely stay in the 40s,
while central Virginia has a shot at reaching the 60s. The
surface front likely remains stalled across the area tonight,
though the baroclinic zone aloft will likely start lifting to
the north. That will likely shift the focus for showers to the
northern half of the area. Low clouds and fog will likely
develop, especially near and north of the front.

Ridging builds over the southeast US as a shortwave trough and
surface low move from the mid Mississippi Valley to the Great
Lakes on Thursday. This could aid in lifting the front north,
although models that perform well in cold air damming continue
to indicate it will have trouble lifting northeast of the
Potomac. Pressure gradients will remain fairly weak, so the lack
of wind may have trouble scouring out the cool dense airmass.
This could result in a temperature gradient from the 50s to 70s
across the forecast area. The greatest chance of showers may
remain to the north for much of the day before the shortwave
grazes by in the late afternoon and evening. A few thunderstorms
can`t be ruled out amongst the showers as there will be some
weak instability.

As the low passes off the Mid Atlantic coast Thursday night,
high pressure moving toward the Canadian Maritimes will likely
shove the front back southward, which could result in the
reemergence of low clouds, fog, and cooler temperatures. There
is very high spread in model forecast temperatures on Friday as
the front will separate an increasingly warm airmass building
northward from the southeastern US. A 30 degree spread in
temperatures could exist from northeast to southwest.
Comparatively, precipitation chances will be lower Friday and
Friday night as ridging aloft builds northward. However, there
still could be some light showers or drizzle near and northeast
of the front.


KEY MESSAGE 2...A weak cold front arrives late Saturday and
slowly pushes through by Sunday night before stalling nearby
early next week.

Saturday may have the best shot at getting the unseasonably warm
airmass across most of the forecast area as a stronger southerly
gradient develops between high pressure off the southeast coast
and low pressure moving through the Great Lakes.

By Saturday afternoon or evening, a weakening cold front will
be dropping towards our region from the northwest. This front
will bring continued chances for some showers and perhaps
thunderstorms with it, mainly Saturday night. By Sunday, the
front will be slowly drifting south, with highest chance for
rain centered along wherever the boundary decides to setup that
day. Right now, that seems to be in the central VA/southern MD
region. At any rate, the front brings very little change in
terms of sensible weather to the region, and barely even a wind
shift. It will solely act as a forcing mechanism for some
showers into early next week. There is a pretty substantial
amount of volatility when it comes to exact temperature
forecasts at this time. It does look to get above normal, but by
how much has yet to be determined still.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A wavering front will result in low ceilings, fog, showers, and
shifting wind directions at times through Friday. The position
of the front will be critical for the development of these
phenomena, and forecast confidence is lower than usual.

For this morning, the front has lifted close to MRB and MTN. Low
clouds have scoured out to the south, although some fog has
attempted to form in the cloud breaks. The front will drift back
south today, with a gradient from VFR to IFR ceilings likely
very close to the metro terminals. Occasional showers will also
continue to spread from west to east most of the day and
evening, with some decreasing trend the second half of tonight.
However, IFR to LIFR conditions will likely develop tonight at
all terminals as the front reaches its most southern extent.

Thursday may see improvements to roughly MRB/IAD/DCA, but the
Baltimore terminals may hang on to low ceilings most of the
day. More showers and perhaps even an embedded thunderstorm will
cross the northern terminals during the late afternoon and
evening. The southern extent of low ceilings is much more
uncertain Thursday night through Friday night, although the
highest chances remain across MRB/BWI/MTN. Overall lower rain
chances are forecast Friday.

Rain chances will continue as a cold front will sweep through
the region from west to east late Saturday through Sunday. This
could result in an extended period of sub-VFR conditions as a
result. Also, a slight chance for a thunderstorm exists on
Saturday afternoon. Otherwise, SW winds around 15-20 knots on
Saturday, tapering off to around 10-15 knots by Sunday.

&&

.MARINE...
A front will waver back and forth across the waters through
Friday night. Near and north of the front, dense fog could form
at times, and that is the case this morning north of Pooles
Island (based on nearby traffic cameras). Visibility could be
variable, but does look to improve after 9 AM based on model
forecasts.

Over these next three days, the northern Chesapeake may largely
keep east to northeast winds, while areas south of
Washington and Bay Bridge could flip to southerly at times.
Winds should remain below advisory criteria.

Winds will gust to near SCA criteria out of the SW on Saturday.
However, thinking that the continued cold waters in comparison to
warmer air temperatures could confine the threat primarily to the
smaller waterways, with less wind over the open Bay waters. Winds
taper off on Sunday, with SCAs unlikely at this time.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Dense Fog Advisory until 9 AM EST this morning for
ANZ530.

&&

$$

DISCUSSION...ADS/CJL
AVIATION...ADS/CJL
MARINE...ADS/CJL

NWS LWX Office Area Forecast Discussion