Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

016
FXUS61 KLWX 181941
AFDLWX

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

.WHAT HAS CHANGED...
Freeze Warnings and Frost Advisories were issued late tonight
into Monday morning for many areas west of I-95. Small Craft
Advisories were issued through Monday. A Gale Watch was issued
Monday evening through Tuesday morning for portions of the
middle Chesapeake Bay.

&&

.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.

Surface high pressure stretches from the Mid Atlantic to the
Canadian Maritimes this afternoon. A closed upper low is located
east of Cape Hatteras, with a surface low about 350 miles
offshore. This low will have little effect locally through
Monday with clear skies continuing, although north to
northeasterly winds will continue to supply cooler air. High
temperatures today are in the 50s to low 60s. Low dew points
this afternoon will recover some tonight, but are still expected
to remain near or below 32F west of I-95. 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 were
issued 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 the Advisory may need to be expanded to
the rest of the piedmont if confidence increases this 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 06 and 12z 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 is
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 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 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 corresponding
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 and 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 with
changes in the weather pattern once again by the October 29-31st
timeframe.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
North/northeasterly winds are 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 been contracting
toward southern Maryland this afternoon and may remain that way
through this evening. 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 to Smith Point 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 today 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 have a chance to 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.
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 8 AM to 6 PM EDT Monday for ANZ531-
     536-539.
     Small Craft Advisory until 6 PM EDT Monday for ANZ532>534-537-
     540>543.
     Gale Watch from Monday evening through Tuesday morning for
     ANZ534-543.

&&

$$

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