Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

082
FXUS61 KLWX 060802
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
402 AM EDT Mon Jul 6 2026

.WHAT HAS CHANGED...
Flood Watches have ended, but additional watches are likely
needed for today`s convective threats. Have lowered dew points
today as the model guidance favored mid/upper 70s which seemed a
bit high. No heat products are needed as forecast highs will
return to near average for early July.

&&

.KEY MESSAGES...
- 1) A risk of a few severe thunderstorms and spotty flash
  flooding continues through Tuesday.

- 2) Seasonable temperatures return mid to late week despite
  continued chances for diurnal showers and thunderstorms.

&&

.DISCUSSION...
KEY MESSAGE 1...A risk of a few severe thunderstorms and spotty
flash flooding continues through Tuesday.

In the wake of another active day of convection, a bulk of the
earlier activity has now shifted off toward the Delmarva
Peninsula. With light winds and saturated low-levels, the
GOES-19 nighttime microphysics channel and observations are
showing increasing stratus over portions of the area. Some of
this may develop into patchy fog, but the potential for dense
fog should be more isolated to local river valleys. Current
temperatures and dew points are in the upper 60s to mid 70s with
little change expected toward daybreak.

The current frontal analysis places a stalled boundary just
south of the Mason-Dixon Line. Expect this particular front to
generally meander about the region the next 24 to 36 hours,
often being shifted around by convective-scale processes. The
pattern aloft features a very broad positively-tilted trough
stretching from the Upper Great Lakes down toward the Ozarks. As
this trough edges eastward, a series of impulses will continue
to ride over the mentioned surface boundary. There is even some
hint of this upper trough weakening, but its remnants would
slowly migrate eastward to the Atlantic coast during the next
several days. All and all, this will lend itself toward
additional active weather days over the Mid-Atlantic region.

For today, there is a threat for both isolated severe
thunderstorms as well as instances of flash flooding. While the
Storm Prediction Center features a Marginal Risk across the
entire area, the Weather Prediction Center maintains a Slight
Risk for flash flooding. The overall thermodynamic profile has
gradually shifted over toward more of a heavy rain signature
versus widespread severe storms. Instability comes down with a
tall/skinny CAPE profile which is supportive of heavy rain
processes. Additionally, the tropical nature of the air mass
will carry precipitable water values into the 2 to 2.25 inch
range. Forecast soundings show light low-level easterlies which
occurs beneath weak westerlies. This will favor some very slow
cell motions and thus a risk for flash flooding.

The timing of today`s convection could be a bit delayed where
low stratus linger beyond the morning hours. However, all signs
point toward destabilization of the boundary layer and resultant
convective initiation over the higher terrain by the mid/late
afternoon. Given minimal capping, other mesoscale features like
the lee-side trough and river/bay breezes will also be sites for
afternoon/evening convection. Based on output from the 00Z
high-resolution suite, evolution of the convection could be
rather chaotic. This would include activity spawning off
colliding outflows, repeat activity, and possible training in a
west-east fashion given unidirectional zonal flow. Flood
Watches will likely be needed for the threat of flash flooding.
The area of greatest concern would be along the I-95 corridor,
and others impacted by heavy rainfall the past 24 to 48 hours
(i.e., Madison, Greene, Montgomery, and portions of Howard
County).

Where this frontal zone lies on Tuesday will dictate the level
of threat for additional active weather. The forecast suggests
this boundary should lie along I-66 during the morning hours
before sagging southward to the Virginia/North Carolina border
by the night. Thus, there is some risk for additional convection
which includes a few severe storms and further flash flooding.
Marginal Risk areas are being advertised for both components of
this system. Mainly overcast skies and northeasterly onshore
winds should hold temperatures below average into Tuesday.
Forecast highs will be in the upper 70s to mid 80s, with upper
60s to 70s for mountain locales.


KEY MESSAGE 2...Seasonable temperatures return mid to late week
despite continued chances for diurnal showers and
thunderstorms.

The early week frontal boundary is forecast to push down into
the Carolinas by mid-week before shearing out shortly after.
There is decent model agreement in the pattern aloft which
favors the stronger belt of westerlies being across New England
into southeastern Canada. This places the local area on the
southern flank of these winds, and thus a more slow moving,
convectively aided shortwave pattern. This is where model
agreement breaks down as each 00Z deterministic places notable
shortwave troughs in variable locations. As a series of
vorticity maxima advance toward the Eastern Seaboard, these
could easily be an impetus toward diurnal convective
development. Thus, expect a pattern that is more seasonable in
nature for early/mid July, but also with a threat for daily
showers and thunderstorms. However, storm organization will
likely not be like recent days. Forecast highs return to the 90
degree mark by Thursday and Friday, but with perhaps a gradual
cool down by the upcoming weekend.


&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
In the wake of earlier convection, a moistening boundary layer
will lower ceilings across all terminals early this morning.
While initially slow to respond, it appears this is fully
underway with IFR ceilings likely through the mid-morning hours.
However, expect this to gradually mix out with the early July
solar insolation angles. Weak gradients will maintain light
winds which will become variable at times. The main convective
window is between 21Z-03Z this evening where restrictions are
likely at times. Some convection may linger a bit longer before
shifting toward another night of low stratus (likely IFR again).

For Tuesday, the main frontal zone slowly begins to pull south
of I-66. However, its close proximity will keep showers and
thunderstorms in the picture again. Additional storm-driven
restrictions are possible in this environment. Expect mainly
northeasterly winds over the area as this boundary continues
pushing southward.

Thereafter, diurnal showers and thunderstorms are possible each
day. While VFR conditions should dominate much of the time, some
restrictions are possible if these storms impact the TAF sites.
Winds turn more south-southwesterlies by Thursday before
shifting to westerly on Friday.

&&

.MARINE...
Weak summertime gradients will largely keep the marine zones
free of Small Craft Advisories. However, additional days of
active convection should lead to a greater threat of Special
Marine Warnings. Besides the gusty thunderstorm winds, other
hazards would include frequent lightning and any outflow winds.
The most active period is likely through Tuesday given a frontal
zone nearby. As this boundary sags southward to the Carolinas,
daily convection becomes less widespread. However, expect a ramp
up by late in the work week as a slow moving upper trough nears
the region. After multiple days of mainly north to northeasterly
flow, winds turn more southerly by Thursday ahead of this
approaching trough.

&&

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

&&

$$

DISCUSSION...BRO
AVIATION...BRO
MARINE...BRO