Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

399
FXUS61 KLWX 051744
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
144 PM EDT Wed Aug 5 2026

.WHAT HAS CHANGED...
A Flood Watch only remains in effect for southern Baltimore and
southeast Harford Counties. Elsewhere, the threat has diminished.

&&

.KEY MESSAGES...
- 1) Warm front lifts north through the afternoon.

- 2) Daily shower and thunderstorm chances are expected through
  early next week.

&&

.DISCUSSION...
KEY MESSAGE...Warm front lifts north through the afternoon.

Latest analysis shows a small meso-low feature near Manassas
VA, and this feature will likely drift northeastward just
northwest of US-29 toward Baltimore`s northwest suburbs through
the afternoon.

On radar and satellite, this feature has the appearance of an
occluded low. The pseudo "triple point" near Baltimore is where
the strongest convergence remains.

The highest PW axis is overhead, so anything that develops will
be capable of very heavy rainfall rates. Slow storm
motions/training are possible as this weak low moves overhead of
northeast MD. Forcing for ascent via moisture flux has ceased,
so further development will rely on subtle convergence axes
and/or heating of an extremely humid airmass through limited
cloud breaks.

Have cancelled the watch as convergence continues to decrease
southwest of Baltimore. Meanwhile, convergence and CAPE will
remain in the Baltimore area through this afternoon. The last
few runs of the HRRR maintain some redevelopment through mid
afternoon, though the strongest convergence is showing signs of
lifting out as of just before 2PM EDT.


KEY MESSAGE 2...Daily shower and thunderstorm chances are expected
through early next week.

In the wake of what morning convection materializes, the models do
show a brief lull in the action. The northward pushing warm front
eventually stalls nearby before shearing out. Likewise, the upper
low across the Mid-South region begins to fill although the
reflection of this circulation still shows up across southern West
Virginia.

A deep southerly flow will continue around high pressure over the
Atlantic, ushering plenty of moisture. PWATS will be near or greater
than 2" in the valleys with 1-2" in the mountains, which is about 1-
2 SD above climo. A surface trough and shortwave energy will trigger
scattered showers/thunderstorms, but it should not be a washout
during the afternoon/evening. The main threat will be brief heavy
downpours and gusty winds. However, DCAPE and shear are on the lower
side, so the probability of severe storms is lower. If some storms
train over the same area, localized flash flooding can occur. The
pattern does favor the possibility for training convection (cloud
layer winds nearly parallel to low-level wind), but the coverage
should be isolated.

A similar pattern will hold on for Thursday and Friday while the
subtropical jet strengthens to the north and west. Therefore, more
showers and thunderstorms are likely along with the threat for
isolated instances of flash flooding and locally damaging wind
gusts. Hotter conditions may cause relatively steeper low-level
lapse rates and the wind field strengthens a bit (especially
Friday).

A quasi-zonal flow aloft will develop for the weekend into next
week, bringing more seasonably hot and humid conditions along with
daily chances for showers and thunderstorms.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Conditions do improve and return to VFR by mid afternoon. PROB30
groups in the TAFs have been removed from IAD/DCA, and replaced
with TEMPOS until 19-20Z at BWI/MTN. PROB30 for possible TS
23z-02Z at MRB as convection develops along a surface trough.

Winds shift to mainly south to southwesterly for the foreseeable
future as a Bermuda high pressure system persists across the western
Atlantic. Daily convective chances each afternoon and evening will
support convective-driven restrictions. With little change in the
upcoming pattern, this sort of forecast will likely hold for the
next several days.

VFR conditions are expected most of the time Saturday and Sunday,
but a few showers and thunderstorms are possible, especially during
the afternoon and evening hours each day.

&&

.MARINE...
Small Craft Advisories could be needed for parts of the waters
at times this week, mainly in the late afternoon to evening.
Otherwise, winds remain around 10 knots. Daily showers and
thunderstorms expected each afternoon this week. Special Marine
Warnings would accompany any of the stronger thunderstorms
capable of producing frequent lightning and wind gusts over 35
knots.

Winds may approach SCA criteria Saturday and Sunday as the gradient
strengthens a bit between high pressure over the Atlantic and lower
pressure to the the north. A few showers and thunderstorms are
possible each day, especially during the afternoon and evening
hours.

&&

.TIDES/COASTAL FLOODING...
Anomalies climb mid to late 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...Flood Watch until 4 PM EDT this afternoon for MDZ011-508.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ533-
     534-543.

&&

$$

DISCUSSION...BJL/DHOF/KRR
AVIATION...BJL/DHOF/KRR
MARINE...BJL/DHOF/KRR