Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

222
FXUS61 KLWX 070703
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
303 AM EDT Sun Jun 7 2026

.WHAT HAS CHANGED...
Stubborn showers persisted ahead of a cold front along the I-70
corridor early this morning, but were showing signs of weakening.
A cold front will drop south today, with a few strong storms
possible in the I-64 corridor. Onshore flow will result in
cooler temperatures Monday into Tuesday before hot and humid
conditions return later this week along with thunderstorm
chances.

&&

.KEY MESSAGES...
- 1)) A cold front descends across the area through tonight,
  and could spark a few showers and thunderstorms especially in
  the I-64 corridor.

- 2) Briefly cooler conditions develop in onshore flow Monday
  into Tuesday.

- 3) Heat, humidity, and thunderstorm chances return mid to late
  week, with heat index values possibly approaching 100.

&&

.DISCUSSION...
KEY MESSAGE 1...A cold front descends across the area through tonight,
and could spark a few showers and thunderstorms especially in
the I-64 corridor.

As of 07Z/3am EDT early this morning, the surface cold front
was still north of the PA Turnpike. Slow but steady southward
progression of the front is expected today as upper troughing
pivots by.

Low-level west to northwest flow across much of the area will
result in downsloping and reduce convergence. However, there may
be enough lingering low-level moisture and lift along the front
to result in a pop up shower or two around midday to early
afternoon pretty much anywhere south of I-70. The best chance
for deeper convection (and any strong to severe wind threat)
looks to be along the I-64 corridor where downsloping effects
will be less and moisture will be deeper.

Lapse rates aloft won`t be quite as steep today as they were
yesterday, but moderate mid-level flow of about 40 kts and steep
low-level lapse rates could still result in 55-65 mph wind gusts
and small hail in some of the strongest cells.

Convection is likely to occur earlier today (initiating
10am-1pm, then dropping south and out of the area by 4-7pm).
This is due to dry air advecting in from the north as the front
drops to the south.

Cooler nighttime lows in the 60s (50s mountains) are expected
with lower humidity tonight into early Monday morning.


KEY MESSAGE 2...Briefly cooler conditions develop in onshore flow
Monday into Tuesday.

A rather stout area of surface high pressure is expected to
build from the Northeast into the Mid-Atlantic early this week
in the wake of the front. This may actually push the front as
far south as Florida by mid week.

Locally, this area of high pressure results in cooler onshore
flow (relatively speaking, though highs still look to be in the
80s). Despite the onshore flow, the origin of the high pressure
is dry so dew points also look to be lower.

The ridge begins to break down on Tuesday as high pressure
nudges to the east. A rogue shower could approach the central
Appalachians Monday afternoon, but better chances for a shower
or thunderstorm exist over the Appalachians Tuesday afternoon.


KEY MESSAGE 3...Heat, humidity, and thunderstorm chances return mid
to late week, with heat index values possibly approaching 100.

As the aforementioned area of high pressure slides offshore,
strong ridging aloft will build over the East Coast. This will
slide a dome of higher heat from the central CONUS into the
local area the second half of the week.

Recent bouts of heat have been somewhat dry/continental in
nature, but this next wave looks to have some more moist/tropical
component to it. The higher humidity may lend toward a more
notable heat index increase. I will caution that the NBM can
sometimes bias-correct too high for dew points in the longer
term depending on the setup (probably due to mesonets that read
too high during these setups), but even lower to mid 90s air
temps with mid to upper 60s dew points would result in 95-100 F
heat index values during the afternoon hours Thursday/Friday.

With the increasing heat and humidity comes increasing shower
and thunderstorm chances. With ridging nearby, flow aloft won`t
be particularly strong. But, the moderate to strongly unstable
airmass could still result in isolated/localized but still
potent storms capable of gusty winds.

A more appreciable front/trough may drift toward the area by
next weekend, though ensemble spread and therefore forecast
uncertainty increases by this time.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A few showers may linger near MRB, BWI and MTN through about
08Z. Otherwise, VFR with mid/high clouds are expected this
morning with gradual clearing today as a cold front slides south
and drier air advects in. Forecast soundings show CINH eroding
by 14Z-16Z, but with ample dry air aloft especially with
northward extent. A shower or two can`t be ruled out just about
anywhere into the early afternoon, but was not confident enough
to mention anywhere except at CHO where moisture will be deeper.
Even there it looks a bit on the early side with probs peaking
16-19Z this afternoon. Otherwise, W/NW winds gust 15-20 kts into
early this evening before becoming light N/NE tonight.

NE to E flow is expected Monday into Monday night, becoming S
Tuesday through Wednesday then SW/W Thursday. VFR conditions
are anticipated with winds AOB 15 kts most of the time, though
some daytime gusts to near 20 kts can`t be ruled out. Despite
the onshore flow Monday, the origin (from a dry high) likely
precludes more widespread lower ceiling potential.

Shower and thunderstorm chances increase the second half of the
week in typical pop up summer fashion.

&&

.MARINE...
West to northwest flow will increase over the narrower
waterways and along the western shore of the Chesapeake Bay
late this morning through early this evening as a cold front
slides south and diurnal mixing increases. Hot air over cooler
water may preclude gustiness over wider/eastern waterways. A
shower or thunderstorm could approach the waters near southern
Maryland this afternoon.

Light north winds are expected tonight, turning northeast to
east on Monday. An increase in onshore flow is expected Monday
which will likely warrant additional SCAs. Dry weather is
expected during this time.

As high pressure drifts offshore Tuesday through Thursday,
southerly flow/channeling effects may prompt SCAs at times.
Winds may become more southwest/west Thursday. Shower and
thunderstorm chances increase the second half of the week.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT this
     evening for ANZ530>533-535-536-538-542.

&&

$$

DISCUSSION...DHOF
AVIATION...DHOF
MARINE...DHOF