Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

337
FXUS61 KLWX 090704
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
304 AM EDT Sun Aug 9 2026

.WHAT HAS CHANGED...
A brief reprieve from t-storms today and turning hotter. T-storm
chances return for the new workweek along with the threat for severe
weather.

&&

.KEY MESSAGES...
- 1) Even less t-storms today with increasing chances for the new
workweek. Turning hotter as well with high humidity continuing.

- 2) Shower and t-storm chances remain through at least Saturday
  ahead of a cold front that will bring needed relief to the
  area.

&&

.DISCUSSION...
KEY MESSAGE 1... Even less t-storms today with increasing chances
for the new workweek. Turning hotter with high humidity continuing.

Not much of a change in the overall synoptic and mesoscale pattern
as we continue in this typical August summertime regime. It`s a
rinse and repeat forecast of hot temperatures, high humidity, and
diurnal thunderstorms chances.

Storm coverage will be at it`s lowest today and potentially
lingering into Monday as we sit between shortwave impulses. The
strengthening subtropical ridge offshore combined with west to
southwest flow aloft should aid in the suppression of convection
today outside of the usual terrain and bay breeze circulations.
Current 00z guidance keeps things fairly isolated over the terrain
and in locations mainly along and south of I-64. Any thunderstorms
that pop up will be short-lived with gusty winds, locally heavy
rainfall, and frequent lightning as the primary concerns.

As for Monday, the chances for thunderstorms have increased given
another piece of shortwave energy ejecting across the region.
Current 00z guidance suggests scattered to numerous thunderstorms
across the region with a focus east of the Alleghenies Monday
afternoon and evening. SPC currently has most of the region in a
Marginal Risk (Level 1 out of 5) for severe weather with a Slight
Risk (Level 2 out of 5) grazing northwest Garrett Co. MD. Machine
guidance is also high on the severe threat with WxNext2
probabilities of 30-60 percent and CSU probabilities of 15 to 30
percent across the area during the Monday into Tuesday timeframe.
Even with that said, coverage and timing remain the two big question
marks similar to what we saw on Saturday across the region. With a
hot and humid airmass in place and marginal shear this will be
something to watch in the near term period.

Additional shortwave disturbances look to pass through Tuesday into
Wednesday and again Wednesday into Thursday. Uncertainty remains in
regards to timing and coverage which will dictate the risk for
severe weather. Current machine learning guidance and day 4-8
outlooks from SPC mention at least a chance for severe weather each
day mainly during the afternoon and evening hours. Ensemble and
deterministic guidance put us in an MCS setup which will make it
even harder to time out severe weather, especially with complexes of
storms moving around the top of the ridge. Once again something that
will continue to monitor in the coming days ahead.

Outside of he storm chances expect highs in the upper 80s and low
90s with heat indices east of the Blue Ridge up around 100 degrees.
The hottest days look to be today and Monday given the strengthened
subtropical ridge nearby. Highs will push into the mid 90s with heat
indices closer to 105 degrees east of the Blue Ridge/along the urban
corridor Monday afternoon.

KEY MESSAGE 2...A cold front could arrive late next week bringing
relief from the heat and humidity into the upcoming weekend.

Daily storm chances look to continue through at least Saturday as a
more potent frontal system tracks toward the region. Ahead of that
front will be several fast moving shortwave disturbances which will
help aid in shower and thunderstorm development during the diurnal
period. Storm coverage is a bit uncertain Thursday into late week as
the front tries to push through. Speaking of the front, details
still remain muddled on it`s passage. Most 00z ensemble guidance
suggests a frontal passage late Thursday into Friday while others
have a front Friday into Saturday. Other deterministic members try
to stall the front to the south Friday into Saturday while bringing
it back north through the end of the weekend into early next week.

With that said, there is even more uncertainty in regards to severe
weather Thursday through Saturday based upon cloud cover and the
placement of the front. Of course any decent frontal passage we`ll
have to be monitor given machine probabilities remaining between 5-
15 percent for severe weather. Temperatures will cool from the 90s
into the low to mid 80s late week. Overnight lows will fall back
into the low to mid 60s with 50s over the mountains.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Prevailing VFR conditions are expected across the terminals through
at least Thursday given subtropical high pressure offshore and the
lack of any real front passing through. Brief periods of sub-VFR are
likely during the afternoon and evening hours due to thunderstorms.

Today will bring the least amount of t-storms between the terminals
given a strengthened subtropical ridge over the region. An isolated
shower or t-storm could pop up this afternoon west of MRB and south
of CHO/SHD between 18z-00z/2-7pm. Coverage will be very isolated in
nature with most seeing nothing at all. Winds will remain light out
of the west and southwest at less than 15 kts.

Storm coverage increases Monday into Tuesday as another shortwave
disturbance passes through. The risk for severe weather is also
increasing during this time with a focus during the peak heating
period 18z-01z/2-8pm Monday afternoon and evening. Storm coverage
remains uncertain with gusty winds, frequent lightning, and locally
heavy rainfall as the primary concerns. Similar conditions are
expected Tuesday and Wednesday with restrictions possible in the
afternoon and evening due to thunderstorms.

Outside of the thunderstorms expect patchy fog between the terminals
each morning through Friday. Winds will remain light out of the west
and southwest at less than 15 kts.

Temporary restrictions will continue at times due to showers and
thunderstorms through at least Saturday as we await a cold front to
sweep through.

&&

.MARINE...
Sub-SCA level winds are expected today with occasional gusts up
to 15 kts over the open waters of the Chesapeake and tidal
Potomac. A brief period of southerly channeling may return to
the open waters Monday afternoon and evening. Overall sub-SCA
level winds are expected through Thursday morning.

Outside of the background winds, expect daily shower and
thunderstorm chances are each afternoon and evening through upcoming
workweek. The least amount of coverage will be today with greater
coverage Monday and Tuesday afternoon/evening. Special Marine
Warnings may be needed to encompass any stronger thunderstorms that
may form. Damaging wind gusts and frequent cloud-to-ground lightning
will be the main threats between 19z-01z/ 3-9pm.

&&

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

&&

$$

DISCUSSION...JMG/EST
AVIATION...JMG/EST
MARINE...JMG/EST