Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

051
FXUS61 KLWX 172327
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
727 PM EDT Sat Oct 17 2026

.WHAT HAS CHANGED...
Other than very slight nudges to hourly observations, no major
changes have been made to the forecast or headlines this evening.

&&

.KEY MESSAGES...
- 1) Below normal temperatures with frost and freeze concerns
  continue through Monday morning.

- 2) A Nor`easter lurks nearby for the new workweek bringing the
  potential for a few showers and breezy conditions, especially
  along and east of I-95.

&&

.DISCUSSION...
KEY MESSAGE 1...Below normal temperatures with frost and freeze
concerns continue through Monday morning.

The trend has continued tonight to keep the center of the
surface high over the upper Ohio Valley. There will be a sharper
pressure gradient on its southeastern flank due to the
developing Nor`easter off the North Carolina coast. While it was
already expected to some extent, winds remaining at least 5 mph
will likely limit how much temperatures can fall east of the
Blue Ridge. Tonight`s cold air will be driven more by advection,
although more widespread decoupling may occur west of the Blue
Ridge closer to the surface high. The elevated winds may
maintain notable temperature/dew point spreads (the latter of
which will be in the upper 20s) to prevent widespread frost
formation, especially east of the Blue Ridge. The Frost Advisory
remains in effect though, since many of these areas in the
piedmont are prone to localized decoupling. While NBM
probabilities of freezing temperatures have decreased from
yesterday, especially east of the Blue Ridge, reliable guidance
does still show pockets of freezing temperatures in the Freeze
Warning area. The highest confidence in widespread subfreezing
temperatures is in the Allegheny and Potomac Highlands, perhaps
over to the central Shenandoah Valley. So in the end, no changes
to those headlines at this time.

The high settles more directly over the area Sunday into Sunday
night, leading to lighter winds and continued dry conditions.
The pressure gradient will increase to the southeast though, so
winds may be a bit more elevated over southern Maryland. Highs
will remain below normal in the mid 50s to near 60. The
position of the high might actually lead to colder conditions in
some areas Sunday night into Monday morning, especially between
I-81 and US-15. Dew points in the upper 20s and lower 30s along
with calm winds make a case for more potential for frost and
freeze conditions west of I-95. Headline decisions will need to
wait until it is determined where the growing season will
continue after tonight.

A gradual warming trend likely starts thereafter, although
temperatures will remain below normal through Monday night.
While there is some uncertainty with the Nor`easter off the
Carolina coast, most guidance keeps it far enough to the
southeast for dry conditions to continue through Monday night.


KEY MESSAGE 2...A Nor`easter lurks nearby for the new workweek
bringing the potential for a few showers and breezy conditions,
especially along and east of I-95.

Uncertainty remains regarding a potential Nor`easter developing
in the vicinity of the NC/VA coast during the early and middle
part of next week. The track of this system will dictate any
rain chances, breezy conditions, and coastal flooding risks
across the region. Current guidance continues to exhibit
moderate spread when it comes to the placement of the low and
timing as it meanders along the coast. Each of the models form a
coastal low on what was the residual upper-level trough and
front from earlier in the weekend. Guidance points to a low
anywhere from 50 to 200 miles off the coast of NC Monday before
meandering generally north heading into midweek. Some of the
guidance retrogrades the low back toward the coast by mid to
late week. Meanwhile, 1035-1037 mb high pressure will remain
wedged along and west of the mountains Monday into Tuesday
before retreating east midweek. A secondary area of 1028-1030 mb
Canadian high pressure will follow Wednesday and Thursday as it
slides east from Ontario into New England before wedging south
late week. It`s not until next weekend when a front crosses the
region.

Synoptically, we sit in an omega block type setup under
predominantly zonal flow. The coastal low offshore combined with
the wedging high in the east will result in breezy northeast
winds at times locally. Meanwhile, ridging will persist in the
center part of the country, with troughiness in the west. With
that said, expect the Nor`easter to have little movement along
the coast throughout the week. As the low fills and potentially
occludes Tuesday through Friday, expect spokes of shortwave
energy to pivot around it. These spokes of energy will drive
any rain shower threat, especially in locations along and east
of I-95. The highest probabilities for rain (at least 20
percent) remain across southern MD, the northern neck of VA, and
perhaps northeast MD during the Monday through Friday
timeframe. Areas further west will likely remain dry with a few
passing clouds. Downsloping west of the Blue Ridge should keep
dry conditions in place throughout next week, unless the
Nor`easter meanders significantly further west. Outside the
rain shower chances will be the concern for wind, marine
issues, and coastal flooding. Right now, wind gusts look to
average between 15 to 25 mph during the Monday afternoon through
Wednesday afternoon timeframe. Higher gusts of 25 to perhaps 35
mph will be most likely down across southern MD and along the
western shore of the Chesapeake Bay where the gradient will be
tighter compared to locations further west. As for marine and
coastal flooding concerns, please see the corresponding
discussions below.

Highs temperatures will top out in the mid to upper 60s (50s
mountains) each day with overnight lows in the upper 30s to mid
40s. Overnight lows warm into the 50s by late week.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Northerly gusts subside this evening, although some occasional
15-20 kt gusts may linger the first half of the night. LLWS is
likely for a few hours at CHO given a bit more noteworthy speed
and direction difference in the lowest 2 kft AGL. Some very
marginal LLWS is possible early Sunday near DCA, as well.

High pressure will build closer by Sunday into Monday, but a
Nor`easter will lurk off the Carolina coast. Any north or
northeasterly gusts to 20 kt will be limited to the daytime
hours. Dry conditions will continue with few or no clouds.

Tuesday through Saturday...Primarily VFR conditions are expected
amongst the terminals with periods of sub-VFR mainly east of BWI,
DCA, and MTN. A few showers are possible on the east side of the ZDC
airspace with the Nor`easter lurking offshore. Winds will
generally be out of the northeast at 10 to 20 kts with gusts up
to 30 kts, especially near the waters.

&&

.MARINE...
The Gale Warning continues until 6 AM Sunday, but recent trends
suggest winds may drop below criteria before that point,
perhaps as early as this evening. Elsewhere, Small Craft
Advisories continue. The upper tidal Potomac River is expected
to drop below SCA criteria late this evening, but the remainder
of the waters likely won`t see wholesale decreases in winds
until sometime Sunday morning. Locations south of the Bay Bridge
and the lower tidal Potomac River will likely keep advisory
conditions most of Sunday. Advisories were issued or extended
accordingly. Advisories will likely need to be extended into
Sunday night for portions of the waters, although the coverage
will depend on the position and strength of a Nor`easter off the
North Carolina coast.

Monday through Thursday...A developing Nor`easter off the Mid-
Atlantic coast will deliver a prolonged period of SCA conditions
and potential gales (mainly over the wider waters of the mid
Chesapeake Bay). Confidence is currently low for gales based
upon the track of the system with projected winds out of the
northeast at 10-20 kts with gusts up to 30 kts at times.

&&

.TIDES/COASTAL FLOODING...
A snapback likely begins tonight as northerly winds begin to
slacken. A developing Nor`easter off the Mid-Atlantic coast
will lead to tidal anomalies rising more into the upcoming week.
Sensitive locations (i.e. Annapolis) will have a chance to
reach minor flooding thresholds during the high tide cycle
Sunday night, and again during the middle of next week.
Considerable uncertainty remains on how exactly this Nor`easter
will track and subsequently affect the tide levels.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Freeze Warning from 1 AM to 9 AM EDT Sunday for MDZ003>006-501-
     502-507-509-510.
     Frost Advisory from 1 AM to 9 AM EDT Sunday for MDZ503-505.
VA...Freeze Warning from 1 AM to 9 AM EDT Sunday for VAZ025>031-
     503>505-507-508.
     Frost Advisory from 1 AM to 9 AM EDT Sunday for VAZ036>040-050-
     051-501-502-506-526.
WV...Freeze Warning from 1 AM to 9 AM EDT Sunday for WVZ050>053-055-
     501>506.
MARINE...Small Craft Advisory until 11 AM EDT Sunday for ANZ530-531-538-
     539.
     Gale Warning until 6 AM EDT Sunday for ANZ532>534-537-543.
     Small Craft Advisory from 6 AM to 6 PM EDT Sunday for
     ANZ532>534-537-543.
     Small Craft Advisory until 11 PM EDT this evening for ANZ535.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ536.
     Small Craft Advisory until 6 PM EDT Sunday for ANZ540>542.

&&

$$

DISCUSSION...ADS/DHOF/EST
AVIATION...ADS/DHOF/EST
MARINE...ADS/DHOF/EST
TIDES/COASTAL FLOODING...LWX