Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

403
FXUS61 KLWX 291402
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1002 AM EDT Sun Mar 29 2026

.WHAT HAS CHANGED...
No changes needed to the forecast at this time. Shower chances
seem to be trending upward for Monday based on early 12Z
guidance.

&&

.KEY MESSAGES...
- 1) A warming trend is expected through Wednesday.

- 2) A frontal passage midway through next week will have
  potential to bring showers and thunderstorms to the region.

&&

.DISCUSSION...
.KEY MESSAGE 1...A warming trend is expected through Wednesday.

12Z IAD sounding shows multiple shallow low level stable layers.
The final mixing height will make the difference between highs
in the upper 50s vs. upper 60s. Waves of high level clouds will
continue to drift overhead today, but most should be thin enough
to allow filtered sun.

Previous discussion:

As high pressure moves offshore through early this week, return
flow will usher in warmer temperatures. Each day through
Tuesday is expected to be about 10 degrees warmer than the
previous day, with Wednesday`s highs similar to Tuesday`s. This
draws many areas to or above 80 degrees by mid week. Overnight
temperatures will rise similarly, with no additional threats of
sub-freezing conditions through the week. South/southwesterly
winds will also remain gusty between the offshore high and a
couple low pressure centers passing over or north of the Great
Lakes. Expect gusts of 20-25 mph each day during peak heating.
The greatest concern for fire weather conditions will be this
afternoon in the residual dry airmass (see the Fire Weather
section below for more details).

Some scattered showers may develop on Monday as a lead
shortwave and broad isentropic upglide lift across the area, but
residual dry air may make more widespread measurable rainfall
hard to come by. Monday will also be relatively cloudier for
the same reasons. Strong ridging over the southeastern states
will likely dominate by Tuesday and keep low pressure/rain well
to the north. However, can`t totally rule out a pop up shower,
mainly over the mountains due to diurnal terrain circulations.


.KEY MESSAGE 2...A frontal passage midway through next week
will have potential to bring showers and thunderstorms to the
region.

Broad ridging is forecast to start breaking down early this
week allowing an upper-level trough to progress eastward to the
north of the region. Strong high pressure is likely to be
anchored over the north-central Atlantic Ocean acting as a
block to the east and southeast. A front associated with the
trough is forecast to drop into the region from the
north/northwest bringing the potential for showers and
thunderstorms Wednesday into Thursday. Uncertainty remains high
on shower/thunderstorm coverage along with overall rainfall
amounts associated with the boundary. Depending on the position
and strength of the high over the Atlantic Ocean, the front
could become hung up over our region becoming a focus for the
continued development of showers and thunderstorms. This
solution would bring the most rain to the region, especially if
the front stalls over the northern parts of our region. If the
high is further offshore and weaker, the front will be able to
progress further south leading to less precipitation totals and
coverage as well as much cooler temperatures. The large model
spread in frontal position is narrowing at least for Thursday,
with increasing confidence the front will push to the south.
However, it may try to lift back north at some point toward the
end of the week. Temperature spread remains large (between 40
and 85 degrees for highs) by the end of the week. The threat
for strong to severe thunderstorms with the frontal passage
Wednesday may be tempered due to the lack stronger upper-level
lift, but there may be enough instability and shear to allow
for some stronger/organized thunderstorms.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
High pressure will drift offshore through early this week,
where it will remain in control of the local weather through
Tuesday. Overall VFR conditions are expected through this
period, though there are some hints of lower ceilings (still
VFR) Monday into Monday night. Some scattered showers are
possible as well on Monday, but any restrictions should be
brief.

The main weather feature over the next few days will be the
wind. Southerly gusts of 20-25 kt will develop during the late
morning and afternoon, increasing steadily after 14Z. Winds may
remain somewhat elevated tonight, although gusts may be more
occasional. Despite strong winds at 925mb, think there should
be enough mixing to preclude LLWS at most terminals. Diurnal
south/southwesterly gusts of 20-25 kt will repeat Monday and
Tuesday.

A frontal passage Wednesday into Thursday could lead to sub-VFR
conditions in showers along with gusty winds shifting from the
south to northwest behind the front. A few thunderstorms are
possible as the front crosses.

&&

.MARINE...
Southerly winds are already increasing this morning on the upper
tidal Potomac, although there is some uncertainty with how
quickly it will do so on the southern Maryland (wider) waters.
The Small Craft Advisory will start at 2 PM in this area, with
it already being in effect elsewhere. The advisory continues
through Monday, although gusts may become more intermittent on
the interior waters tonight.

The area will remain between the offshore high and a frontal
system across the Great Lakes Monday and Tuesday. Small Craft
Advisories will likely be needed in the gusty south to southwest
flow during this period. There may not be much of a drop in
winds during the overnight hours, either.

Small Craft Advisories are possible Wednesday and Thursday
along with the potential for Special Marine Warnings due to
thunderstorms with the frontal passage Wednesday into Thursday.

&&

.FIRE WEATHER...
High pressure will drift offshore through Tuesday. A quick warm
up ensues through Wednesday. A frontal system stalled northwest of
the area will eventually drop southward into the area Wednesday
bringing repetitive chances for showers and possibly thunderstorms
through the end of the week as it stalls nearby. The front may
return north at the end of the week.

A dry airmass will remain over the area early this week. Minimum
RH values will drop to 20-35 percent this afternoon. Southwest
winds will also gust 15-25 mph through the day. Fine fuels will
continue to dry, so there will likely be an elevated risk for
fire spread this afternoon.

Temperatures will continue to warm through Wednesday, although
humidity will likewise increase, so the fire weather threat may
decline somewhat.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 6 PM EDT Monday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ530>532-535-
     536-538>540.
     Small Craft Advisory from 2 PM this afternoon to 6 PM EDT
     Monday for ANZ533-534-537-541>543.

&&

$$

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