Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

990
FXUS61 KLWX 080639
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
239 AM EDT Sat Aug 8 2026

.WHAT HAS CHANGED...
Scattered thunderstorm chances again this afternoon with even less
coverage Sunday and Monday as hotter temperatures build in.


&&

.KEY MESSAGES...
- 1) Typical Summertime pattern continues with building heat next
week. Storm chances today decreasing Sunday and Monday.

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

&&

.DISCUSSION...
KEY MESSAGE 1... Typical Summertime pattern continues with building
heat next week. Storm chances today decreasing Sunday and Monday.

It`s a typical Summertime pattern as we enter the second weekend and
week of August. The forecast is on repeat with patchy morning dense
fog giving way to hot and humid conditions with late day afternoon
and evening thunderstorms.

Today, we`ll bring another passing shortwave disturbance which will
trigger an additional round of afternoon and evening strong
thunderstorms. Thunderstorm coverage will be a bit less due to mid
level west to west/west-southwest flow yielding some downsloping
flow east of the mountains. This is a stark contrast to the
southerly flow over the past few days yielding locally higher storm
coverage.

Storms today will be isolated to scattered with a focus again along
and north of I-66/US-50 and east of the Allegheny Mountains.
Instability will remain high as a result of the high heat and
humidity. Shear values will sit around 30 to 35 kts as the
subtropical jet stream begins to strengthen. This could yield a more
organized severe weather threat which aligns with current learning
machine guidance that suggest 15-30 percent probabilities for
damaging wind gusts this afternoon and evening. Thermodynamic
profiles also depict this sentiment with skinnier CAPE profiles and
inverted-V signatures towards the surface yielding a higher ceiling
for damaging wind potential. The Storm Prediction Center continues a
Marginal Risk for severe weather (Level 1 out of 5) for this
afternoon and evening with wind as the primary threat. Isolated
instances of flooding also cannot be ruled out, especially over the
urban areas around Baltimore/DC given the repetitive heavy rains the
last few days.

Convection wanes a bit Sunday into Monday given quasi-zonal flow
aloft and the strengthen upper level ridge axis nearby. A few storms
may develop over the higher elevations, but coverage will be much
less than in recent days. This will be short-lived however, with
storm chances increasing once again Tuesday through the end of the
week as a series of shortwave disturbances pass through.

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 Monday and Tuesday given the
strengthened subtropical ridge over the region. Highs will push into
the mid 90s with heat indices closer to 105 degrees east of the Blue
Ridge/along the urban corridor.

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 Friday 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 with activity remaining
isolated to scattered Tuesday becoming a scattered to numerous
Wednesday into late week as the front tries to push through.
Speaking of the front, details remain a bit murky on it`s passage.
Most 00z ensemble/deterministic guidance suggests a frontal passage
Thursday afternoon into Saturday. Guidance also depicts an MCS type
setup during the Tuesday and Wednesday timeframe. Machine learning
guidance is grabbing onto this as well with probabilities running
between 15 to 30 percent for severe weather during the midweek
timeframe. SPC mentions areas back toward our west on the Day 4 and
5 outlook, so something we`ll continue to monitor, especially as the
subtropical ridge flattens.

There is a bit more uncertainty in regards to severe weather
Thursday through Saturday. Of course with any decent frontal passage
will have to be monitor given machine probabilities remaining
between 5-30 percent for severe weather. This will ultimately be
determined by the timing of the front in regards to the peak heating
period. Temperatures will cool from the 90s into the 80s late week.
Weather does look to improve for the upcoming weekend as Canadian
high pressure works into the region.


&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Prevailing VFR conditions are expected across the terminals through
the middle of next week 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.

For today, expect storms to fire west of MRB between 15-18z/11am-2
pm before advancing eastward into the corridor (IAD-BWI-DCA) between
20-01z/4-9pm. PROB30s will be used to encompass this threat given
the coverage being isolated to scattered across the region. Storm
coverage drops off even more Sunday and Monday with chances
primarily west of MRB and south of CHO/SHD. Outside of the
thunderstorms expect patchy fog between the terminals each morning
through early next week. Winds will remain light out of the west and
southwest at less than 15 kts.

Temporary restrictions will continue at times through at least
Friday as we await a cold front to sweep through.

&&

.MARINE...
Small Craft Advisories have been issued for portions of the open
water due to southerly channeling mainly later this afternoon and
evening. Most days will see marginal conditions just below the SCA
threshold. Daily shower and thunderstorm chances are expected each
afternoon and evening through early next week. The greatest coverage
will be this afternoon/evening with a brief reprieve Sunday and
Monday. Special Marine Warnings may be needed to encompass any
any stronger thunderstorms that may form. Damaging wind gusts
and frequent cloud-to-ground lightning will be the main threats
between 18z-23z/ 2-7pm.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies remain elevated through early next week in response
to return southerly flow. Periods of coastal flooding are possible
at times of high tide at sensitive locations.

&&

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

&&

$$

DISCUSSION...CJL/EST
AVIATION...CJL/EST
MARINE...CJL/EST