266
FXUS61 KLWX 121342
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
942 AM EDT Wed Mar 12 2025

.SYNOPSIS...
A front will waver near the Mid Atlantic over the next several
days before retreating back to the north as a warm front
Saturday. A stronger cold front will cross the area Sunday. High
pressure will build in from the west early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
MORNING UPDATE: No changes were made to the forecast at this
time, see previous discussion for details.

PREVIOUS DISCUSSION: A weak cold front is sinking into the area
this morning while high pressure moves toward the St. Lawrence
Valley. The front is noted only by a wind shift to the north, as
well as some mid and high level clouds over the northern half
of the forecast area. The surface boundary and associated cooler
air is shallow, so it will have some difficulty moving too far
south into the area. From central Virginia into the Potomac
Highlands, winds will quickly take on a more southerly
component, and these areas will likely rise into the 70s again
with plentiful sunshine. However, winds will remain more
easterly closer to I-95, leading to a cooler marine fetch. The
coolest temperatures will be in northeastern Maryland, where
highs may stay in the upper 50s. A weak wave of low pressure
will move along the boundary into the upper Ohio Valley toward
this evening, but it looks like any chance of showers should
remain north of the area. A slight increase in humidity may
reduce fire weather concerns compared to previous days, although
continued drying of fuels should be noted.

Winds become more northeasterly tonight as high pressure
strengthens over Maine. The cooler fetch will help saturate low
levels, with stratus likely developing the second half of the
night. There is some uncertainty how far inland this spreads,
with the highest chance of clouds east of the Blue Ridge. There
is also some signal for patchy fog on the southern flank of the
cloud bank. Lows will range from the upper 30s to mid 40s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The front will remain near the Mid Atlantic Thursday and Friday,
if anything sinking southward with time as a weak low develops
off the coast. Stratus will continue to make the forecast
challenging as east to northeast winds aid in maintaining a
cooler and more moist near-surface airmass. The most challenging
temperature forecast is for Thursday since the front will still
be nearby and the extent of the initial stratus deck is
uncertain. Have favored cloudier and cooler high resolution
guidance, which keeps highs in the lower 50s in northeast
Maryland and the lower 70s in portions of the Potomac Highlands
and southern Shenandoah Valley/Nelson County. However, some
models indicate the clouds mix out in the afternoon, which would
result in a wider expanse of warmer temperatures. One other
thing to note with the front remaining draped near the
Appalachian spine is that a shortwave trough will be crossing
the area during the afternoon and evening. This combination
could spark a few showers mainly along and west of I-81.

There is a signal for more widespread stratus Thursday and
Friday nights as the front sinks farther south and winds become
easterly across most of the area. Some patchy drizzle can`t be
ruled out as the moisture becomes deeper. The main question for
Friday is where and if the clouds mix out, as this could make
the difference in highs in the 50s vs. 60s. Overnight lows will
be in the 40s both nights.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
On Saturday, a potent low pressure system will track across the
great lakes with the associated warm front expected to lift through
the forecast area. Southerly flow will usher in plenty of warm and
moist air with mostly cloudy skies and temperatures in the upper 60s
to mid 70s expected. Precipitation chances increase ahead of the cold
front as moisture increases, with a chance of rain showers
throughout the day. Wind gusts between 15 and 20 knots are expected
in the afternoon with higher gusts exceeding 30 knots possible along
the ridges. Overnight low temperatures will be quite warm compared
to previous nights as southerly flow continues to bring in above
normal temperatures. Lows will be in the upper 50s to mid 60s across
the forecast area.

The cold front will push through the region on Sunday, bringing a
threat of severe thunderstorms. The parent trough continues to
trend more positively tilted, although the 00Z GFS continues to
show a prominent negative tilt. While this is still 5 days out
and forecast uncertainty remains, ample moisture and strong
deep-layer shear could lead to heavy rainfall and severe
thunderstorms capable of producing damaging wind gusts.

By Monday morning, the cold front will be departing off the east
coast as precipitation chances decrease throughout the day. Cooler
temperatures are expected in the wake of the cold front with high
temperatures in the 50s to low 60s across the area. Those at higher
elevations will stay in the 40s. Overnight low temperatures will be
in the 30s areawide. Conditions dry out areawide on Tuesday as high
pressure builds in over the region. Temperatures begin moderating
with high temperatures expected to be in the 60s. Overnight lows
will be a few degrees warmer than the night prior, with temperatures
in the 40s.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
A weak front is settling across the area this morning which will
waver across the area through Friday. Wind direction will be
changeable but generally less than 10 kt over the next 24 hours,
shifting north behind the front, becoming southeast later today,
then back to the east or northeast tonight into Thursday. VFR
conditions will prevail through this evening. However, stratus
is forecast to move onshore late tonight, most likely affecting
the metro terminals. CHO and MRB may be closer to the edge. Have
the highest confidence in MVFR to IFR conditions, although some
guidance does indicate LIFR.

Stratus will likely be a recurring issue Thursday and Friday
nights as well, with higher IFR probabilities across all
terminals. The main uncertainty is whether the stratus mixes out
each afternoon or remains in place. Even if ceilings remain,
there should be improvement in flight category. Patchy drizzle
could also develop Thursday and Friday nights. Otherwise light
NE to E winds are expected during this time.

Sub-VFR ceilings and visibilities are likely Saturday and Sunday as
an approaching cold front brings widespread showers and
possible thunderstorms to the terminals. Southerly winds on
Saturday gust 15 to 20 knots across all the terminals with the
exception being KMRB where gusts near 25 knots are possible.
Winds increase overnight into Sunday with SW winds gusting 25 to
30 knots. Winds shift to northwesterly behind the frontal
passage, with gusts between 15 and 20 knots expected overnight.

&&

.MARINE...
A dry cold front is dropping through the waters this morning.
There have been a few very sporadic 15 to 20 knot gusts, mainly
over the open waters, but nothing worth issuing an SCA over at
this time. Things look to be stable enough to ward off
widespread advisory conditions today given the warm air over
cold waters.

The front will waver near the area through Friday night. At
this time, winds are forecast to remain below advisory
thresholds, with direction fluctuating between NE and SE.

SCA conditions are likely Saturday and Sunday as a cold front
approaches and moves over the waters. SMWs are possible as
widespread showers and possible thunderstorms impact the waters
on Sunday.

&&

.FIRE WEATHER...
While winds will generally be lighter today, some gusts in the
15-25 mph range are possible this afternoon, especially on the
ridges. Dry weather will continue with mostly sunny to sunny
skies, so fuels will continue to dry, although there may be a
slight increase in humidity as a dry front wavers near the area.
Minimum humidity will generally be between 30 and 40 percent,
but some locations could drop into the 20s depending on the
balance of temperatures and dew points near the front.
Conditions will be monitored for the potential need of an
elevated fire weather statement. Humidity recoveries between 65
to 90 percent are forecast Wednesday night.

Dry conditions will likely continue through Friday night,
although some patchy drizzle could occur during the early
morning hours. With the front gradually settling to the south,
easterly winds will bring an increasing marine influence with
more clouds and higher humidity. Will have to monitor the
southern and western flanks of the forecast area however, where
the front could hang up and result in warmer, less humid
conditions.

While showers are possible Saturday, a more significant wetting
rain remains likely Sunday as a strong frontal system pushes
through the area. Thunderstorms and strong gradient winds are
also possible Sunday.

&&

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

&&

$$

SYNOPSIS...ADS
NEAR TERM...ADS/CJL
SHORT TERM...ADS
LONG TERM...AVS
AVIATION...ADS/AVS
MARINE...ADS/CJL/AVS
FIRE WEATHER...ADS