Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

505
FXUS61 KLWX 240736
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
336 AM EDT Mon Aug 24 2026

.WHAT HAS CHANGED...
Expanded on the mid-week thunderstorm threat in Key Message 2.
Severe threat is low, but not zero Thursday afternoon/evening.

&&

.KEY MESSAGES...
- 1) Dry conditions anticipated through early portions of the
  week.

- 2) Warmer and more humid conditions return mid-week, with
  thunderstorm chances returning by Thursday.

&&

.DISCUSSION...
KEY MESSAGE 1...Dry conditions anticipated through early
portions of the week.

High pressure will continue to slowly build toward the area on
Monday and Tuesday, resulting in dry conditions and lower
humidity levels. High temperatures will generally be in the
upper 70s to mid 80s, with overnight lows in the 50s to lower
60s.


KEY MESSAGE 2...Warmer and more humid conditions return mid-
week, with thunderstorm chances returning by Thursday.

Heading into Wednesday, dry, pleasant conditions continue into
much of the day and afternoon. As an upper level ridge over the
midwest begins to flatten in amplitude, southwesterly mid-level
winds advect tropical moisture northward into our region. As
this tropical air mass moves through our region, humid
conditions return through the end of the week. A weak piece of
shortwave energy is also expected to approach the region
Wednesday evening, which could spark a few storms in the
evening/overnight hours.

As the upper trough over the northeast CONUS starts to push more
offshore on Wednesday, we will see some subtle rises in 500 hPa
heights. This, paired with a developing southerly surface wind
pattern will yield more typical August warmth and increased
humidity. Expect high temperatures in the upper 80s to near 90,
along with dew points increasing into the low to mid 60s. The
ridge doesn`t will only be overhead during the day though, as
another piece of shortwave energy rotates through late in the
evening into the overnight. There won`t be a lot of instability
left over when this rotates through, but there may be enough to
pop off a few overnight showers.

By Thursday, after a day of southerly flow ahead of an
approaching cold front from the west, humidity will jump
markedly. Temperatures remain in the mid 80s to low 90s, but dew
points jump into the upper 60s and perhaps even into the low
70s. The aforementioned cold front will come through during the
day Thursday. If timed during peak heating, there could be
around 1000 to 1500 J/kg of MLCAPE to work with. The shortwave
is subtle, with only about 20 kts of deep layer shear showing up
in most guidance. So, the threat for organized severe weather is
rather low. Additionally, this is not one of the extreme
heat/humidity setups, so thinking is a more isolated wind threat
at this point. Latest AI medium-range guidance generally
agrees, painting anywhere from 5 to 15 percent severe probs over
the region depending on which one you use.

By Friday, the front should be mostly offshore. However, there
is still the slight chance that it lingers somewhere near/east
of I-95, which could bring renewed afternoon storm chances.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Prevailing VFR conditions and westerly winds are expected at the
terminals through Tuesday. Winds today will be around 5 to 10
knots, with gusts up to 18 knots. Wind Tuesday will be a little
lighter.

Light to gentle winds turn southerly Wednesday afternoon.
Initial VFR conditions could deteriorate as showers and
thunderstorms potentially move in Wednesday night. Additional
showers and storms may be possible on Thursday with continued
southerly winds.

&&

.MARINE...
West to northwesterly winds are forecast over the waters through
Tuesday as high pressure gradually approaches from the Ohio
Valley.

Winds shift southerly by Wednesday, with winds gusting above SCA
thresholds later that evening in a classic southerly channeling
event ahead of an approaching cold front. Southerly winds
nearing SCA criteria continue into Thursday afternoon as well.

&&

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

&&

$$

DISCUSSION...CJL/SRT
AVIATION...CJL/SRT
MARINE...CJL/SRT