Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

801
FXUS61 KLWX 240746
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
346 AM EDT Fri Apr 24 2026

.WHAT HAS CHANGED...
The signal for afternoon convection has consolidated for today
with the main threat area stretching from east of the Blue Ridge
to the Chesapeake Bay. Any severe threat will be very isolated
given the lack of vertical shear.

&&

.KEY MESSAGES...
1) A frontal boundary will linger nearby through Saturday, leading
to chances for showers and thunderstorms at times.

 2) High pressure builds in early next week, before the next system
approaches from the west on Tuesday.

&&

.DISCUSSION...
KEY MESSAGE 1...A frontal boundary will linger nearby through
Saturday, leading to chances for showers and thunderstorms at times.

The latest surface analysis places a wavy stationary boundary
just north of the Mason-Dixon Line. This frontal system extends
back across much of the Great Lakes to a triple point low center
over eastern Minnesota. Locally within the warm/moist sector a
seasonably mild air mass remains in place with widespread early
morning temperatures in the mid 50s to low 60s. This is
accompanied by some passing mid/high clouds, but conditions are
dry amidst mostly light winds.

Looking ahead, the key synoptic players are a robust upper low
spinning across much of the Northern Rockies/adjacent Plains
region into south-central Canada as well as a separate low off
the coast of Nova Scotia. The Eastern Seaboard is largely in
between these two systems while a broad ridge begins to break
down. It is this reduction in heights coupled with ample
mid/late April heating that will ignite isolated to scattered
afternoon showers and thunderstorms. Model soundings show rather
weak deep layer shear, coupled with ample low-level dry air.
Any of the more robust high based storms could yield some
damaging winds given evaporational cooling effects. Downdraft
CAPE (DCAPE) values average around 600 J/kg which is fairly
marginal in terms of downburst potential.

The 00Z HREF 40-dBZ paintball plots depict the main threat area
would be east of the Blue Ridge toward the Chesapeake Bay,
mainly in the 2-7 PM timeframe. Any additional threat for
thunderstorms should largely wane after dark with the loss of
diabatic heating. After seeing today`s highs push into the mid
70s to mid 80s, temperatures will come crashing down on
Saturday as the frontal zone sags southward.

Overnight conditions will be overcast with low temperatures in
the low/mid 50s. By early Saturday morning, the parent front is
forecast to be along or just south of I-64. A cool easterly
flow will make for a chillier day to the north of this boundary.
Rain chances remain plentiful as moisture and lift overrun this
quasi-stationary baroclinic zone. For those along/north of I-66
and U.S. 50, mid 50s to mid 60s are expected (coolest over
northeastern Maryland). Closer to the I-64 corridor, highs could
near 80 degrees although this is dependent on whether the area
remains in the warm sector or not.

Some rain chances continue into the evening as well as Saturday
night. Forecast lows will be cooler than the previous night with
widespread temperatures in the 40s.


KEY MESSAGE 2...High pressure builds in early next week, before the
next system approaches from the west on Tuesday.

The aforementioned upper level disturbance will progress off to our
east on Sunday, causing showers to wind down from west to east
during the morning hours. Upper ridging will build in its wake, and
hold strong overhead through much of Monday and Tuesday. However,
high pressure will remain in place to our northeast. As a result,
persistent onshore flow is expected. This should lead to below
normal temperatures and more in the way of clouds than sun.
Temperatures on Sunday, Monday, and Tuesday should reach up into the
60s during the day, and then drop back into the 40s at night.

An upper trough and associated surface low will track into the Great
Lakes on Tuesday. As of now, it looks like we`ll stay stable, so
just showers are expected Tuesday afternoon into Tuesday night as
large scale ascent ahead of that system overspreads the area.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR conditions are expected across all terminals through the
morning hours, with initial light winds given weak gradients.
Isolated to scattered showers and thunderstorms break out this
afternoon as peak heating commences. This could yield some
restrictions at any of the TAF sites, mainly in the 2-7 PM
timeframe. Any issues related to convection should wane toward
nightfall.

The meandering frontal zone slowly pushes south of the area
overnight yielding a steady easterly winds into Saturday. This
increase in maritime influences will yield lowering ceilings and
further rain chances. Sub-VFR conditions are looking likely
across much of the region on Saturday. Based on aviation
guidance, daytime conditions could even lower to IFR at times.
Low ceilings persist into Saturday night with widespread IFR
conditions likely. Winds eventually shift to northeasterly as
high pressure builds to the north. A few showers are possible,
but expect improvement to flight conditions on Sunday.

Light winds Monday morning become easterly, blowing 5 to 10 knots in
the afternoon. Winds become southeasterly overnight before shifting
to the south and gusting around 15 knots Tuesday afternoon. Daily
precipitation chances will lead to possible flight restrictions with
thunderstorms possible on Tuesday.

&&

.MARINE...
A frontal zone currently stretches north of the waters up across
central Pennsylvania. Weak gradients will keep marine winds
below advisory thresholds. Isolated to scattered convection may
fire up this afternoon with daytime heating. A couple of the
more robust cells would be capable of Special Marine Warnings
given some downburst potential.

As the frontal zones sags southward across the area, winds shift
to easterly tonight into Saturday. Winds could approach 20 knots
over the southern waters by early Saturday before becoming more
widespread through the day. Consequently, Small Craft Advisories
will likely be needed across most marine zones on Saturday.
Winds further increase in strength on Saturday night with a
shift to northeasterlies. Gusts up to 20 to 25 knots are
possible. As high pressure builds to the north, local marine
wind fields shift to northerly with channeling effects possible
on Sunday. Additional Small Craft Advisories will likely be
needed.

East winds remain below Small Craft Advisory criteria on Monday
before becoming shifting to southeast and then southerly overnight
into Tuesday. Small Craft Advisories are possible Tuesday afternoon
as winds near criteria. As a cold front approaches and crosses over
the waters, thunderstorms are possible. SMWs may be needed Tuesday
afternoon.

&&

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

&&

$$

DISCUSSION...AVS/BRO/KJP/EST
AVIATION...AVS/BRO
MARINE...AVS/BRO