Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

565
FXUS61 KLWX 220659
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
259 AM EDT Sun Mar 22 2026

.WHAT HAS CHANGED...
Slightly later timing of cold frontal passage may keep brunt of
severe weather north of the area or across far northern parts of
the area.

&&

.KEY MESSAGES...
-1) Cold front could bring severe thunderstorms this
 evening/tonight.

-2) Quiet weather expected through Wednesday with moderating
 temperatures late week. Shower chances return Thursday and
 Friday as a cold front approaches the region.

&&

.DISCUSSION...
KEY MESSAGE 1...Cold front could bring severe thunderstorms this
evening/tonight.

S`ly winds will persist through the day. This will result in
low-level moisture increasing, with some potential for fog/low
clouds by daybreak especially east of the Blue Ridge. Any low
clouds or fog should burn off quickly this morning.

Notably warmer today with SW`ly flow advecting well above
average temps into the region (H85 temps of 15-17C). Have added
a climate section (below) to account for near record heat today. Most
of the forecast area should climb into the 80s, with some
locations potentially even making it into the mid- upper 80s.

Guidance has trended slightly slower with cold frontal passage
across local area, potentially delaying storms until after
sunset. The front itself is rather strong and will be over PA
during peak heating. This will result in showers and
thunderstorms developing north of us during the afternoon hours.
Across the local area, almost every sounding/model analyzed has
capping through the day with a lingering EML. At this point,
very low chance of storms developing ahead of the front. The
aforementioned storms over PA will likely drift SE toward
northern Maryland shortly after dark. As low-levels stabilize
with loss of daytime heating, the trend should be for these
storms to gradually weaken as they move into our FA.

The environment to our north across PA looks very favorable for
the development of severe thunderstorms, with a CAPE/shear
parameter space capable of producing both supercells and bowing
segments. As storms do move in after dark, they could still
potentially produce severe hail, even if they`re elevated.
Today is a day to watch for severe thunderstorms, but as it
stands now, it may be a near miss for most of the area, with the
capping serving as a potential saving grace.

The day 1 SPC update has little change across the FA with a
Slight Risk (Level 2 out of 5) in the northern third of the area
and Marginal Risk (Level 1 out of 5) elsewhere. SPC also has
far northwestern portions of the FA in a sig hail outlook
(indicating the potential for 2+" hailstones). That hints at the
potential high ceiling for the severity of storms tomorrow, if
they maintain their strength southward into our forecast area.
As of now, the most likely timing for storms looks to be between
8 PM and Midnight, with remnant showers moving southward along
with the cold front through the entire FA later during the
overnight hours.

KEY MESSAGE 2...Benign weather is likely during mid week before
a cold front brings higher rain chances Thursday night into
Friday.

Winds will shift to out of the NW behind the cold front on
Mon. Conditions will dry out and temps will be much cooler (but
near normal), with highs for most in the 50s and lower 60s (40s
mtns). Winds will gust to around 25-35 mph out of the NW.

High pressure will build overhead Tue with dry conditions and
below avg temps.

Surface high pressure will continue to drift offshore Wed into
Wed night with a subtle shortwave trof/weak backdoor front
passing across the area Thu. This will touch off a few light
showers across the mtns and northern portions of the FA.
Confidence in this occurring is low given ample dry air leftover
in the low levels with high pressure close enough offshore to
provide some lingering influence across the area.

Meanwhile, surface low pressure will work across the St. Lawrence
Valley of Canada. This low will eventually shove a frontal zone
southward into the area late Thu night into Fri. The front will
be slow to cross Fri with due to the placement of the low up
over Canada/northern Great Lakes and an incumbent deepening
trough ejecting east from the southern Plain/Mid-South region.
The front will sag southward as a cold front Fri evening into
Fri night while becoming parallel to the upper level flow.

With that said, plenty of model spread remains per the latest 00z
guidance in regards to timing, placement of surface features,
temperatures, and rain amounts late week. Thus the position of this
potentially wavering frontal zone may have some impacts on
temps Thu and Fri, though they should be near or above normal.

Most of the guidance has the front south of the area Sat with
Canadian high pressure building back over the region. This will
a bring a return to near or slightly below normal temps for the
weekend.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
S`ly winds expected to continue through the day ahead of cold
frontal passage. There remains a signal that low clouds and/or
fog may try to form by daybreak. For now, TAFs have been kept
MVFR, but IFR CIGs are hinted at with a scattered group. Any low
clouds or fog should quickly burn off this morning, leading to
VFR conditions once again through much of the day. Winds will
gradually pick up out of the SW, and could gust around 20 to
perhaps 30 kts during the late afternoon/evening hours.

Aforementioned cold front will bring shower and t-storm chances
this evening/tonight. Sub-VFR CIGs and VSBYs may both be
possible at times. Any precip should come to an end by daybreak
Mon, but winds will remain gusty (25-35 knots) out of the NW
during the day Mon.

VFR conditions are expected with Canadian high pressure Tue and
Wed. Sub-VFR conditions return for some terminals Thu as a
backdoor front drops into the region. S`ly winds may gust to
around 25 kts on Thu as a low pressure system passes well to the
north. More widespread sub-VFR conditions are expected with a
strong cold front Fri.

&&

.MARINE...
Sub-SCA s`ly winds continue through daybreak. Winds gradually
pick up out of the S to SW through the day, and could reach
low-end SCA levels by the late afternoon/evening hours. However,
warm air moving over much cooler waters could limit mixing and
resultant wind speeds, especially over the wider waters. One
place mixing should be efficient is over the middle and upper
tidal Potomac River (narrower waterways) so have an SCA to
account for this.

A strong cold front will move over the waters tonight, causing
winds to shift to out of the N. Showers and a few thunderstorms
may accompany the frontal passage, with the best chance for
storms across northern portions of the Bay (SMWs may be needed).
Chances for precip will come to an end by daybreak Mon, but
winds will remain gusty out of the NW through the day. SCAs
will likely be needed Mon into Mon night.

High pressure will provide light winds Tue. SW winds may begin
to increase Tue night into Wed and may approach SCA levels. SCAs
possible Thu and again Fri as the next front pushes in.

&&

.CLIMATE...
Record daily high temperatures are possible on Sunday (March 22).
Below is a list of records for the date.

Site       Record/Year Set
DCA        90/1907
BWI        86/1907
IAD        83/1968
DMH        79/1955
NAK        82/1948
HGR        88/1907
MRB        84/1966
CHO        92/1907

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 6 PM EDT this
     evening for ANZ535-536.

&&

$$

DISCUSSION...CPB/EST/KJP
AVIATION...CPB/EST
MARINE...CPB/EST