Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

095
FXUS61 KLWX 031916
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
316 PM EDT Mon Aug 3 2026

.WHAT HAS CHANGED...
With an uptick in convective potential this afternoon, a few
Special Marine Warnings and Severe Thunderstorm Warnings have
been issued in the last hour or two. However, these storms are
still on track to exit the forecast area by the early evening.

&&

.KEY MESSAGES...
- 1) Heavy rainfall is possible this afternoon and evening,
  mainly south of I-66, before turning quieter into Tuesday.

- 2) Increased shower and thunderstorm chances Thursday into
  early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Heavy rainfall is possible this afternoon and
evening, mainly south of I-66, before turning quieter into
Tuesday.

A cold front is currently on the move as it edges south of
I-66/U.S. 50. The latest KLWX WSR-88 radar imagery shows a
broken line of storms moving well south/east of the Capital
Beltway back down toward the central Virginia Piedmont and I-64
corridor. Although some of these cells continue to pulse up, the
overall severe risk appears on the lower end as multiple gust
fronts/outflows race out ahead. As of the mid-afternoon hours,
the most consolidated area of showers and embedded thunderstorms
continues over Albemarle, Orange, and Spotsylvania counties in
central Virginia. With a bulk of this area in a severe/extreme
(D2-D3) drought, it will likely take quite a bit of torrential
rainfall to flood. All of this convection is forecast to
continue nosing south and east before exiting the entire
forecast area by the early evening.

For areas to the north of the convection, skies have cleared out
rather quickly. A few local exceptions are noted as anvil cirrus
lift northeastward to near the metro areas. This drying effect
is evident on the multi-channel water vapor imagery as the mean
longwave trough axis passes through. While the stronger forcing
is displaced well to the north into upstate New York and
southern Quebec, enough height falls cross the local area to
push this front through. By late this evening, the cold front is
expected to span southeastern Virginia back across interior
North Carolina. The post-frontal air mass will remain dry with
decreasing cloud cover.

After spending much of the day in the low/mid 80s, expect
temperatures and dew points to fall into tonight. With high
pressure building in from the upper Ohio Valley, forecast lows
are to fall into the upper 50s to 60s. For the Alleghenies, some
locations could even push into the mid 50s. The Shenandoah
Valley westward may see some patchy fog for locations that fully
decouple overnight under clear skies and light winds.

During subsequent days through mid-week, expect more tranquil
weather to arrive on Tuesday. High pressure remains in charge as
the stalled front sticks closer to the Virginia Tidewater
region. Clouds increase from the south as moisture overruns the
frontal system to the south. Despite the clouds, forecast highs
push back into the 80s, but with lower humidity levels.
Seasonable conditions persist into Tuesday night while a few
showers approach from central Virginia and the Northern Neck of
Virginia.

Wednesday yields the next shot for showers and thunderstorms. At
the synoptic level, a cut-off low over the southeastern U.S.
weakens/shears while subtropical ridging retrogrades toward the
Atlantic coast. As this occurs, mid-level winds begin to
increase along the western flank of the offshore anticyclone. A
series of perturbations in the flow will lift across the area at
the same time the surface front returns to the I-95 corridor.
Precipitable water values shift back to over 2 inches which will
not only increase humidity levels, but also bring heavy rainfall
back to the forecast. A Marginal Risk for excessive rainfall
exists on Wednesday as this pattern shift unfolds. Highs remain
in the 80s with afternoon heat indices into the mid 90s.


KEY MESSAGE 2: Increased shower and thunderstorm chances
Thursday into early next week.

Synoptically, we are still monitoring the progression of an upper
level low pressure system over the Ohio River Valley/central
Appalachians. This system will be slow to push eastward heading into
the weekend and early next week. At the surface, is a
stalled/washed out boundary that will act as a catalyst for several
pieces of shortwave energy to move along yielding increased chances
for showers and thunderstorms during the afternoon and evening
periods each day.

Additional showers and thunderstorms are likely Thursday through
Sunday given the boundary washing out over the area. The warm/moist
airmass combined with the washed out boundary and ripples of
shortwave energy will aid in scattered to numerous diurnal
thunderstorm development. Severe weather could be a concern each
day, but overall confidence remains uncertain due to abundant cloud
cover and no real forcing mechanisms. Expect much of the convection
to be driven by terrain circulations or bay/river breeze
interactions. Current machine learning probabilities remain between
15-30 percent Thursday through Monday with 30-45 percent
probabilities east of the Blue Ridge Friday. Friday may be the day
where we have a more pronounced severe threat due to a lee side
trough combined with 30-40kt mid level flow driving convection
eastward. Locally damaging wind gusts will be the primary threat
with storms along with isolated instances of flash flooding.

Expect PWATS to remain between the 75th-90th percentile right on
through early next week. This is due to the lack of any real airmass
changing cold front holding off until the (beyond Tuesday) middle or
end of next week per latest long range guidance. As a result expect
increased humidity and above average temperatures across the region.
Highs will range from the mid to upper 80s and low 90s each
afternoon with heat indices up around 100 degrees east of the Blue
Ridge and over the I-95 metros late week. Once again it won`t be
raining all the time with plenty of dry time in between. Plan for
seasonable summer temperatures and oppressive humidity through the
extended period.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
With frontal convection now well south of the D.C. and Baltimore
terminals, the only TAF site with restrictions is KCHO. A
cluster of slow moving strong to severe thunderstorms remains
around the terminal this afternoon. Have maintained a TEMPO
group until 20Z to account for this convective threat.
Otherwise, VFR conditions should prevail for all sites through
Tuesday as the front sags off toward the south. Multiple wind
shifts will occur during this time as initial post-frontal
northwesterlies turn more northeast to easterly in time. A
shift to southerlies is expected by Wednesday as the system
returns northward as a warm front. This brings shower and
thunderstorm chances which carries the potential for a few
restrictions.

Expect periods of sub-VFR conditions to continue at times Thursday
through the upcoming weekend given increased chances for showers and
thunderstorms. The greatest coverage storms will be during the
afternoon and evening hours each day. Winds switch back to the south
and southwest Wednesday through the remainder of the workweek.
Speeds generally less than 15 kts.

&&

.MARINE...
As frontal convection slowly pushes toward the south and east,
the threat for Special Marine Warnings exists over southern
portions of the tidal Potomac and Chesapeake Bay. This all
should wind down by the early evening at the latest. Post-
frontal northwesterlies are expected into the night before
shifting to northeasterly early Tuesday. Some uptick in gusts to
around 15 knots are possible as this wind shift occurs.
Otherwise, wind speeds do not really pick up until Wednesday as
southerly flow returns. Channeling effects across the wider
waters of the Chesapeake Bay could again reach 15 knots or so.
Convective chances return with the warm front which could yield
frequent lightning strikes and gusty marine winds.

SCA level southerly channeling is expected Thursday afternoon
through Saturday for portions of the waters. A few showers &
thunderstorms are possible over the waters during this period due to
a stalled front nearby. SMWs may be needed to encompass this threat
during the afternoon and evening hours.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies will continue to remain elevated through much of the
day before dropping Tuesday due to a wind shift. Additional
coastal flooding is possible at times of high tide as sensitive
locations as a result. Anomalies climb again mid to late week in
response to return southerly flow.


&&

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

&&

$$

DISCUSSION...BRO/EST
AVIATION...BRO/EST
MARINE...BRO/EST
TIDES/COASTAL FLOODING...EST/BRO