Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

737
FXUS61 KLWX 280646
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
246 AM EDT Wed Oct 28 2026

.WHAT HAS CHANGED...
Have made a few tweaks to the sky and fog aspects of the
forecast over the next 24 to 36 hours to align with the latest
trends. Overall, there are no significant changes to forecast
thinking from the previous cycle, though rain chances have
trended down for Sunday.

&&

.KEY MESSAGES...
- 1) Low clouds and fog through Thursday morning.

- 2) Well above normal temperatures Thursday and Friday
  afternoons, then more seasonable Saturday.

- 3) On-and-off rain showers are possible beginning Sunday into
  early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Low clouds and fog through Thursday morning.

Onshore flow developing around high pressure to the north and
east, as well as a weak warm front slowly lifting across the
Mid-Atlantic, will set the stage for increasing low-level
moisture. This results in the development of low clouds and fog
for much of the area, focused on the next couple of mornings.

For this morning, areas between I-95 and the Blue Ridge and
Catoctin Mountains are favored as moisture banks up against the
higher terrain, as well as the eastern West Virginia panhandle
as moisture seeps through the Potomac River Valley. Nighttime
microphysics RGB and fog difference channels from GOES-E show
this well early this morning, with the development of river
valley fog around an area of stratus developing over northern
Virginia into north-central Maryland as of 06Z/2AM EDT. Though
low clouds are favored, they may be thin at first, with areas of
fog continuing to develop due to radiational cooling of a
modified/moistening low-level airmass. Low clouds likely linger
through midday into early afternoon closer to the eastern
(upslope) areas between the Blue Ridge/Catoctin Mountains and
US-15. Some drizzle is possible along the eastern slopes of the
Blue Ridge/Catoctin Mountains.

Warm advection mid-level clouds may then persist much of the
day as the weak warm front lifts north and moistening onshore
flow continues. This is expected to keep temperatures a few
degrees cooler this afternoon when compared to the previous
couple of afternoons (i.e. upper 60s instead of lower 70s).

Low clouds and some fog redevelop by late evening, persisting
into Thursday morning. Given a slightly more southeast (versus
east) component to the low-level wind, this may allow low
clouds/fog to expand further east to and across the I-95
corridor. Southern Maryland to the Northern Neck of Virginia are
closer in proximity to the moisture sources of the Atlantic
Ocean, Chesapeake Bay and tidal Potomac River, and may therefore
have a chance at some drizzle by early Thursday.

More appreciable clearing is expected by mid/late Thursday
morning as winds shift to a bit west of south, helping to scour
out some of the low-level moisture.


KEY MESSAGE 2...Well above normal temperatures Thursday and Friday
afternoons, then more seasonable Saturday.

Following a wind shift to the south and southwest on Thursday,
well above normal temperatures are expected. Afternoon high
temperatures reach into the lower to middle 70s. A dry front
looks to cross the area Friday turning winds to the northwest,
though I hesitate to call this a cold front with the lack of
cold air advection in its wake. The airmass will be drier, and
that coupled with downsloping flow is expected to push high
temperatures well into the middle to upper 70s on Friday. While
this is a solid 8 to 15 degrees above normal for late October,
it is still several degrees shy of daily records.

Some cold advection does take hold Friday night in the wake of a
secondary boundary as winds shift to the north. This should
allow for low temperatures to fall into the upper 30s and 40s.

A combination of subtle cold air advection and increased clouds
ahead of troughing developing over the middle of the country
will result in more seasonable daytime high temperatures on
Saturday - generally in the 60s (50s mountains). Anticipate lows
dropping into the 40s Saturday night with a continued increase
in clouds but near zero chance of precipitation.


KEY MESSAGE 3...On-and-off rain showers are possible beginning
Sunday into early next week.

A broad area of low pressure will form over the Midwest, and
then track east late in the weekend. There is a potential for
rain showers beginning on Sunday, though it has trended drier
over the past several model runs. Mentionable precipitation
chances now hold off until Sunday evening in the latest forecast
package. These chances linger into Monday. Temperatures remain
in the upper 60s for highs Sunday and Monday (50s mountains),
near to slightly above average for the start of November.

As the initial system tracks offshore by Tuesday, a second,
potentially more potent upper-level low could form over the
Plains and make its way to the region by the middle of next
week. Uncertainty remains high regarding the track of this
system, but this could bring additional rainfall to the region.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Early morning satellite and surface observations confirm the
development of an IFR stratus deck between CHO and IAD. This
will expand through daybreak amid light onshore flow, likely
spilling through the Potomac River Valley up to around MRB.
Restrictions are less certain at DCA and BWI, and especially
MTN. Any low clouds that develop may linger until late morning
around IAD, and early afternoon around CHO/MRB. A period of
L/IFR is likely west of the I-95 terminals around daybreak
through mid morning, before lifting to MVFR and eventually VFR
heading into the afternoon.

Additional low clouds or fog are expected to develop late this
evening into the overnight, with higher potential reaching
further east into the I-95 corridor TAF sites as light east
winds shift to southeast. Clouds should lift mid to late morning
Thursday as winds shift to the south and southwest in the wake
of a lifting warm front, with VFR then likely through Friday as
a dry cold front approaches/crosses. Winds will shift to the
northwest Friday, north Friday night, then northeast to east on
Saturday as another area of high pressure builds to the north.

Sunday has been trending drier as high pressure persists,
although there is increasing uncertainty at this range of the
forecast. Light southerly winds are expected during this time.

&&

.MARINE...
Light east to southeast flow is expected through tonight. A
couple of rogue gusts around 15 to perhaps 20 knots can`t be
ruled out at times given favorable trajectories for channeling,
but the background gradients are weak. Winds shift to the south
and southwest Thursday at similar speeds, then become northwest
to north Friday into Friday night. There may be an increase in
winds due to increased vertical mixing over near-shore/narrower
waterways Friday afternoon, with northerly channeling more
likely to bring gusts closer to SCA thresholds Friday night.

Winds then remain below SCA thresholds through the weekend.
Winds become northeast to east Saturday, then southerly Sunday.

&&

.TIDES/COASTAL FLOODING...
Light onshore flow through Thursday may push sensitive
shoreline close to minor flood stage. Areas most at risk for
reaching minor tidal flood thresholds would be places like
Annapolis and Alexandria mainly during the evening tide cycles
(which are astronomically higher).

Light offshore flow should lower tidal anomalies Friday into
Saturday, before light southerly flow possibly causes at least a
small rebound on Sunday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...DHOF/CPB
AVIATION...DHOF/CPB
MARINE...DHOF/CPB
TIDES/COASTAL FLOODING...DHOF