Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

559
FXUS61 KLWX 210814
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
314 AM EST Sat Feb 21 2026

.WHAT HAS CHANGED...
Winter Storm Watches have been expanded to encompass the remaining
western shore of Maryland. A slight uptick in snow totals given the
northern/westward progression of coastal low pressure Sunday into
Monday.

&&

.KEY MESSAGES...
-1) Winter Storm Watches remain in effect for portions of the area
Sunday into Monday. Highest confidence for impactful snow appears to
be along and east of I-95 as well as across the Allegheny Mountains.

-2) Multiple fronts will cross the area mid to late next week
 amidst a general warming trend.

&&

.DISCUSSION...
KEY MESSAGE 1...Winter Storm Watches remain in effect for portions
of the area Sunday into Monday. Highest confidence for impactful
snow appears to be along and east of I-95 as well as across the
Allegheny Mountains.

Winter Storm Watches have been expanded along the remaining western
shore of Maryland given a slight westward progression amongst the
guidance. Overall the 00z model suite remains fairly consistent on
the track of low pressure from the southeast U.S later today and off
the Carolina coast tonight before shifting north toward the Delmarva
coast Sunday afternoon into Sunday night. Some questions remain in
how close to the coast the low pressure system is and it`s
interaction with an inverted trough that looks to set up in the
vicinity of the area Sunday evening into Monday.

The 00z Canadian and European solutions continue to trend a little
closer to coast with the low pressure system similar to the NAM/GFS
counterparts. Even with that said, the low still remains 200-400 NM
away from Washington DC and Baltimore, pulling the bullseye of
substantial snow toward areas east of the I-95 corridor.

Precipitation is expected to develop across the area predawn Sunday
morning on the north side of developing surface low pressure to the
southeast. It should be initially fall as rain or rain/snow mix as
the low-levels will be too warm. In addition, the precipitation
intensity initially will be light, so that any snow that falls will
have a difficult time accumulating on roads other than grassy areas
or at high elevations above 1500 feet. Most of the Sunday should be
wet with a snow/rain mix falling at temperatures around 34 to 38
degrees.

Any impactful snow (especially to road surfaces) looks to hold off
until late Sunday evening into Monday morning. Lows Sunday night
into Monday will fall close to freezing with teens and 20s over the
mountains. This is when low pressure deepens off the coast and the
upper level trough/inverted surface trough swings through. The wild
card here is the interaction between these features with most of the
guidance showing a narrow corridor of strong lift between
central/northern MD down through northern VA and into the VA
northern neck. This area seems to have the least amount of
uncertainty with respect to QPF according to the latest 00Z EPS/GEFS
ensembles with QPF amounts generally around three quarters of an
inch liquid equivalent. While snow ratios will likely BE lower than
normal (less than 10:1 especially to start), potential banding may
offset lower ratios and more marginal temperatures Sunday night into
Monday morning as colder air pushes in. General model consensus
remains at a widespread 2 to 5 inches of snow along and north of I-
66/US-50 with lesser amounts in the Shenandoah Valley/central VA
Piedmont and higher amounts along the western favored slopes of
the Alleghenies as well as east of I-95. The probabilities for
4" of snow remain between 60 and 80 percent over the
Alleghenies/crest of the Blue Ridge with 40-50 percent probs
further east into the metro areas. These numbers come down into
the 35 to 45 percent range for 6" with the highest percentages
over the mountains and east of the I- 95 corridor. Any wiggle in
track and placement of the inverted trough could move the
needle up or down for these totals. Given the variability any
warning or advisory decisions will likely be made on the day
shift today or at the latest this evening.

The snow will likely continue through Sunday night before tapering
in intensity or exiting the area around daybreak Monday. Gusty NW
winds 25-40 mph) will follow Monday in the wake of the storm.
Elsewhere, light snow is expected Sunday night tapering off after
midnight from west to east, except in the mountain areas where
upslope flow will continue to generate snow showers.

Highs Monday warm back into the mid 30s and low 40s outside the
mountains. Overnight lows Monday night fall back into the teens and
low 20s and cold air advection returns in the wake of the
system.


KEY MESSAGE 2..Multiple fronts will cross the area mid to late next
week amidst a general warming trend.

Temperatures will remain below normal Tuesday and Tuesday night
amidst broad troughing in the eastern US. A clipper type system will
move into the Great Lakes Tuesday night into Wednesday morning. The
warm advection portion of this system could bring some snow to the
Allegheny Mountains. Some guidance has a little precipitation
spilling to the east across northern portions of the area, but this
is more uncertain. Southerly flow behind the warm front will usher
in warmer conditions for Wednesday and Thursday. Model spread
increases during this time with respect to forcing features, but
eventually a cold front may reach the area Thursday or Friday. Any
precipitation with this front would likely be rain, although there
are some solutions that push the front through earlier with a second
wave of low pressure potentially bringing wintry weather to the
Alleghenies. In the end, cold advection won`t be too strong with
this front, and near to above normal temperatures will likely end
the week

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Still monitoring the progression of a cold frontal boundary as
it departs to the south of the area this morning. This has
resulted in a wind shift from the northeast toward more of a
westerly direction this morning. Still getting a few gusts
between 20-25 kts mainly in the lee of the Alleghenies and
Catoctins (i.e at KCBE and KMRB). Lighter gusts have been
reported at KJYO and KIAD on the order of 15 kts. LLWS has also
been observed across the corridor, but looks to diminish prior
to sunrise 08-10z. Overall looking at lighter winds out of the
westerly direction today at less than 15 kts. VFR conditions
will prevail as brief high pressure settles south of the region.
High level clouds will return from the south and west this
evening with lower ceilings tonight as a series of low pressure
systems advance toward the region.

Precipitation is expected to arrive early Sunday in the form of rain
or a rain/snow mix initially before transitioning to snow later in
the afternoon/evening. Precip will push toward KMRB and KSHD/KCHO
prior to 10z before spreading toward the metros thereafter. The main
window of accumulating snow looks to be Sunday evening and night
with the passage of upper low/inverted trough. Snow accumulations
(slushy, wet, and heavy consistency) right now look to sit between 2-
5 inches across the corridor with higher totals east of BWI/DCA.
These totals are subject to change based upon any shifts in the
track of the coastal low and placement of the upper level low
nearby. Expect flight restrictions Sunday night due to snow. Gusty
winds 25-35 kt Monday on the backside of the storm with VFR
conditions likely to returns

Northwest wind gusts in excess of 20 kt will likely continue into
Tuesday. A warm front may bring sub-VFR ceilings and low
precipitation chances Wednesday.

&&

.MARINE...
Sub-SCA level winds are expected today as a cold front sinks south
and weak high pressure builds over the waters. Winds will remain
light and variable, generally out of the west at less than 15 kts.
SCA conditions develop again Sunday due to tightening pressure
gradient with gale conditions likely for the open waters Sunday
night through Monday evening. Gale Watches have been issued for the
entire bay and lower tidal Potomac to encompass this threat with
potential upgrades to warnings later today.

Small Craft Advisory conditions will likely continue Tuesday in
northwest flow. Winds will be lighter Tuesday night, shifting to the
south. Southerly winds will increase Wednesday, potentially nearing
advisory criteria later in the day.

&&

.TIDES/COASTAL FLOODING...
Tides are uncertain with potential coastal storm Sunday into
Monday given divergent model solutions on the track/strength.
While some tidal flooding can`t be ruled out, a more probable
outcome is that strong north winds could result in dropping
tide levels.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Winter Storm Watch from Sunday afternoon through Monday
     morning for MDZ004>006-008-011-014-017-018-503-505>508.
     Gale Watch from Sunday evening through Monday afternoon for
     MDZ008.
     Winter Storm Watch from late tonight through Monday afternoon
     for MDZ509-510.
VA...Winter Storm Watch from Sunday afternoon through Monday
     morning for VAZ505.
     Winter Storm Watch from late tonight through Monday afternoon
     for VAZ503.
     Winter Storm Watch from Sunday morning through late Sunday
     night for VAZ507-508.
WV...Winter Storm Watch from late tonight through Monday afternoon
     for WVZ501-505.
MARINE...Winter Storm Watch from Sunday afternoon through Monday
     morning for ANZ530.
     Gale Watch from Sunday evening through Monday afternoon for
     ANZ530>534-537>543.

&&

$$

DISCUSSION...EST
AVIATION...ADS/EST
MARINE...ADS/EST