Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

124
FXUS61 KLWX 190114
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
914 PM EDT Sun Oct 18 2026

.WHAT HAS CHANGED...
Issued a Coastal Flood Advisory for Anne Arundel County
(Annapolis) for tonight`s high tide.

&&

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

- 2) Uncertainty remains in regards to the track and potential
  impacts from a nearby Nor`easter this week.

&&

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

The pressure gradient will start increasing from the southeast
the second half of the night, but most areas west of I-95 should
largely remain decoupled. Therefore, Freeze Warnings and Frost
Advisories remain in effect for much of this area (the growing
season ended Sunday morning west of the Blue Ridge). The Freeze
Warning may be somewhat marginal, but thought the western areas
that have the lightest winds, lowest dew points, and deeper
valleys and basins (i.e., the Culpeper Basin) have a reasonable
chance of reaching freezing. It`s possible some patchy frost may
form over the rest of the piedmont, though the light wind
developing after midnight in most guidance keeps confidence too
low for a headline expansion as of early evening. Some areas
may be colder tonight compared to Sunday morning since
radiational cooling conditions may be slightly more favorable
(less wind). Locations west of the Blue Ridge could drop into
the 20s.

Temperatures and dew points will climb slightly Monday and
Monday night, with additional Frost Advisories appearing
unlikely.


KEY MESSAGE 2...Uncertainty remains in regards to the track and
potential impacts from a nearby Nor`easter this week.

Overall not too much change in the weather pattern for the upcoming
workweek. An "Omega Block" remains with troughiness in the eastern
and western U.S. along with ridging in the center part of the
country. At the surface is a developing Nor`easter off the Carolina
coast that will gradually meander north and east throughout the
week. With the Omega Block, expect zonal flow aloft and not
much of a west-to-east movement of storm systems across the
country. In turn, this will hold the Nor`easter offshore of the
Mid-Atlantic through mid to late week.

Current model guidance still shows subtle differences in
regards to the placement and timing of the Nor`easter this week,
although some consistency has been made amongst recent model
runs. The EC is fairly clustered and well offshore, while the
GEFS/CMCE are slightly closer to the coast. Each of these
solutions and their corresponding members seem to keep the low
pressure system far enough offshore with perhaps an isolated
shower making it as far west as southern MD/western shore of the
Chesapeake Bay and the northern neck of VA mid to late week.
The probability for precipitation has trended downward given
strong 1034-1038 mb high pressure retreating Monday followed up
by a secondary 1028-1032 mb wedging Canadian high pressure
Tuesday through Thursday.

As a result, expect most locations to remain dry with some passing
clouds from time to time in inland areas as spokes of shortwave
energy pivot around the Nor`easter offshore. Each of these
shortwaves will deliver an uptick in wind out of the north and
northeast, mainly during the afternoon and evening periods. Any
impactful weather will be tied to coastal communities along the
Chesapeake Bay and points east. Confidence remains medium for
at least some periods of gusty north/northeast winds and
potentially some coastal flooding concerns this week. We will
continue to monitor the progress of this developing system. See
marine and coastal flooding discussions below.

Over time, the ridging north of the closed low will allow the
airmass to modify. 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 late week.

The Nor`easter will pull away Thursday into Friday with an even
stronger wedging high pressure system building this weekend. Dry
conditions look to continue for most through middle of next week
with changes in the weather pattern once again by the October
29th-31st timeframe.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Given light gradients, DCA/BWI/MTN have briefly developed a
light east to southeast wind. Wind direction may be somewhat
variable (to calm) this evening before a steadier light wind
develops overnight especially for the metros.

Otherwise, north/northeasterly winds persist through Monday,
gusting around 15 knots each afternoon. Winds shift to
northwesterly on Tuesday, gusting 15 to 20 knots in the
afternoon. VFR conditions are expected each day with surface
high pressure yielding dry conditions.

Primarily VFR conditions are expected through Friday amongst
the terminals as a Nor`easter meanders offshore. An isolated
shower or two will accompany the system mainly over the Delmarva
peninsula/east side of the ZDC airspace. Winds will generally
be out of the northeast at generally 10 to 20 kts with
occasional bouts of gusts up to 30 kts, especially near the
waters. Winds will remain elevated at terminals near the waters
through the upcoming weekend.

&&

.MARINE...
Marginal Small Craft Advisory conditions have contracted toward
southern Maryland this evening, and likely remain that way
until after midnight. Have re-oriented the Small Craft Advisory
as a result. As a Nor`easter well offshore starts drifting
northward tonight, the pressure gradient will tighten, and
stronger winds will likely expand back northward. This wind
field expands a bit further Monday, with an ensuing expansion of
the Small Craft Advisories. The gradient may be the tightest
Monday night into Tuesday. A Gale Watch has been issued from
Drum Point MD to Smith Point VA including Tangier Sound, where
guidance indicates some potential for marginal gale-force gusts.

The Nor`easter off the Mid-Atlantic coast will deliver a
prolonged period of high end SCA conditions and potential gales
(mainly over the central/lower waters). Confidence remains 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. There may be another uptick in the winds Tuesday
night, with decreasing chances for gale conditions thereafter.

&&

.TIDES/COASTAL FLOODING...
Tides are snapping back as northerly winds slacken. A
developing Nor`easter off the Mid-Atlantic coast will lead to
tidal anomalies continuing to rise into the upcoming week.
Sensitive locations (i.e. Annapolis) will likely reach minor
flooding thresholds during the high tide cycle tonight. Guidance
indicates more locations could reach minor flood stage by
Tuesday into Wednesday. However, considerable uncertainty
remains on how exactly this Nor`easter will track and
subsequently affect the tide levels. Elevated water levels
likely won`t decline until late in the week due to the stagnant
weather pattern.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Freeze Warning from 1 AM to 9 AM EDT Monday for MDZ004-005.
     Frost Advisory from 1 AM to 9 AM EDT Monday for MDZ006-503>507.
     Coastal Flood Advisory until 3 AM EDT Monday for MDZ014.
VA...Freeze Warning from 1 AM to 9 AM EDT Monday for VAZ051-501-502-
     505.
     Frost Advisory from 1 AM to 9 AM EDT Monday for VAZ038>040-050-
     053-506-526-527.
WV...None.
MARINE...Small Craft Advisory from noon to 6 PM EDT Monday for ANZ530-
     535-538.
     Small Craft Advisory from 8 AM to 6 PM EDT Monday for ANZ531-
     536-539.
     Small Craft Advisory from 3 AM to 6 PM EDT Monday for ANZ532-
     540>542.
     Small Craft Advisory until 6 PM EDT Monday for ANZ533.
     Small Craft Advisory until 6 PM EDT Monday for ANZ534-537-543.
     Gale Watch from Monday evening through Tuesday morning for
     ANZ534-543.

&&

$$

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