Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

655
FXUS61 KLWX 170800
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT Tue Mar 17 2026

.WHAT HAS CHANGED...
With Gale Warnings ending at 1 AM, have put out Small Craft
Advisories which run through 7 PM this evening. Additionally,
with snow squalls possible at times, Winter Weather Advisories
have been extended until 5 PM across the Allegheny Front. While
not changing the foreast yet, may add isolated snow showers east
of the mountains to today`s forecast given the high spillover
potential of snow streamers.

&&

.KEY MESSAGES...
-1) A period of upslope snow showers are expected along and
 west of the Allegheny Front through this afternoon.

-2) Below normal temperatures are expected through Wednesday
 before seasonable weather returns for the remainder of the
 week.

&&

.DISCUSSION...
KEY MESSAGE 1...A period of upslope snow showers are expected
along and west of the Allegheny Front through this afternoon.

After spreading a broad swath of 55 to 70 mph wind gusts along
and east of U.S. 15, the powerful cold front is now located just
off the Atlantic coast. Cold advection has been quite rapid as
temperatures have quickly fallen back into the upper 20s to mid
30s.

In the wake, per regional radar, a number of snow showers in
the form of streamers are coming off the Great Lakes. VAD wind
profilers show unidirectional westerly flow which is generally
how these snow showers are aligning. While most of the action
has been along and west of the Allegheny Front, radar trends
indicate some spillover effects as such showers push into the
I-81 corridor. Have updated the early morning forecast to match
such trends.

With temperatures in the teens to mid 20s, there will certainly
be no question of precipitation type across mountain locales.
During the late morning to afternoon period, the 00Z NAM snow
squall parameter lights up across the Ohio Valley toward the
Allegheny Front. With Froude numbers becoming quite large today
(5 to 7), a significant amount of spillover is possible. Plan on
expanding the threat of snow showers further to the east.
Meanwhile, over the Alleghenies, have extended Winter Weather
Advisories until 5 PM to account for the snow squall potential.
Another 2 to 4 inches of snow are possible, which comes with
continued blustery westerly winds. Given gusts up to 50 to 55
mph, Wind Advisories continue over this mountain chain through
midday. Elsewhere, dry and gusty winds increase during the
afternoon, but should stay below advisory criteria.


KEY MESSAGE 2...Below normal temperatures are expected through
Wednesday before seasonable weather returns for the remainder
of the week.

The influence of the earlier frontal passage has yielded a
dramatic fall in temperatures. After seeing above average
temperatures yesterday/Monday, today`s forecast highs will drop
by around 20 to 35 degrees. More specifically, many are forecast
to see highs in the mid 30s to low 40s, with upper teens to 20s
in the mountains. Blustery westerly winds on the order of 25 to
35 mph will lower wind chills across the metros to around
freezing. This is accompanied by passing clouds and a few snow
showers that stream off the higher terrain. Winds gradually
decrease into tonight as an anticyclone over the Ohio Valley
treks toward the Eastern Seaboard. Despite some residual winds
and cloud cover, lows tonight plunge into the upper teens to 20s
(teens for the mountains).

The continental-scale pattern continues to support deep
troughing across the eastern U.S. as an anomalous ridge sits
over the southwestern states. While the initial stronger
shortwave pulls out into the Atlantic, a weaker trough begins to
dig across the Great Lakes and northeastern U.S. This will
maintain a cyclonic flow regime into Wednesday which supports
continued below average temperatures. While most again stay in
the upper 30s to low 40s, expect a warming trend along the
Alleghenies as snow comes to an end. Overnight conditions will
also not be quite as cold owing to a shift to southerly flow.

Over the next several days, the synoptic features will slowly
move eastward in time. This moves troughing off the Atlantic
coast while ridging tracks into the Rockies. In the net, heights
gradually rise through the late week period which fosters a
warming trend. Surface high pressure largely dominates the
mid/late week pattern which will support a dry forecast. Over
the weekend, multi-ensemble temperature spread increases as a
more pronounced system may impact the region. Precipitation
chances are low at this time, but temperatures likely peak over
the weekend with highs well into the 60s. However, Sunday has
the most volatility as the 75th percentile forecast high in D.C.
is 74 degrees and the 25th percentile is 52 degrees. Thus, the
shift to cooler weather could start as early as Sunday.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
With a post-frontal air mass now in place, a return to VFR
conditions has occurred. Expect it to stay that way through much
of the week. Overall, the main issue today is the blustery
westerly winds which may gust up to 30 knots at times this
afternoon. Such winds should diminish beyond sunset as high
pressure moves in from the Ohio Valley.

This area of high pressure takes over during the mid to late
week period which allows for continued VFR conditions. Winds
shift to southerly by Wednesday and Thursday, but with less wind
than recent days owing to weaker gradients. Winds turn more
southwesterly by Friday while increasing in strength by
Saturday. Some light shower chances come in by late Friday, but
restrictions look unlikely at this time.

&&

.MARINE...
Behind the strong cold front which is now just offshore of the
Atlantic coast, winds have dropped below gale strength. In the
wake, westerly winds should remain blustery in nature through
this evening. Small Craft Advisories have been issued across all
waters through 7 PM this evening for west-northwesterly gusts
of 25 to 30 knots, accompanied by waves of 2 to 4 feet. Such
advisories will likely need to be extended into some of tonight
given residual gusts around 20 to 25 knots.

High pressure builds over the area during the mid to late week
period. This favors sub-advisory winds as gradients will be
weak. Prevailing southerlies are likely in this regime before
shifting to southwesterly by Friday. Some increase in winds are
possible by Saturday which may approach advisory levels, but
confidence is low.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 7 PM EDT this evening for MDZ008.
     Wind Advisory until 11 AM EDT this morning for MDZ509.
     Winter Weather Advisory until 11 AM EDT this morning for
     MDZ509-510.
     Winter Weather Advisory from 4 PM to 5 PM EDT this afternoon
     for MDZ509-510.
VA...Winter Weather Advisory until 11 AM EDT this morning for
     VAZ503.
     Winter Weather Advisory from 4 PM to 5 PM EDT this afternoon
     for VAZ503.
     Wind Advisory until 2 PM EDT this afternoon for VAZ503.
WV...Winter Weather Advisory until 11 AM EDT this morning for
     WVZ501-505.
     Winter Weather Advisory from 4 PM to 5 PM EDT this afternoon
     for WVZ501-505.
     Wind Advisory until 2 PM EDT this afternoon for WVZ501-505.
MARINE...Small Craft Advisory until 7 PM EDT this evening for
     ANZ530>543.

&&

$$

DISCUSSION...BRO
AVIATION...BRO
MARINE...BRO