Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

125
FXUS61 KLWX 051300
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
900 AM EDT Sun Jul 5 2026

.WHAT HAS CHANGED...
Evaluating the threat for flooding with incoming guidance over
the next 24 to 48 hours. Widespread sunshine this morning will
result in instability setting the stage for thunderstorms this
afternoon and evening as a cold front slides in from the north.

&&

.KEY MESSAGES...
- 1) Remaining hot today with Heat Advisories in effect along
  the I-95 corridor and back into central Virginia.

- 2) A risk of severe thunderstorms and flash flooding exists
  through Monday.

- 3) More seasonable conditions return by mid/late week.

&&

.DISCUSSION...
KEY MESSAGE 1...Remaining hot today with Heat Advisories in
effect along the I-95 corridor and back into central Virginia.

Today will be another hot day given continued above average
mid/upper heights. However, the forecast does keep readings
below the century mark with the warmer spots being east of the
Blue Ridge (mid/upper 90s). Given ample low-level moisture, dew
points remain elevated which will carry heat indices into the
100 to 107 degree range. Heat Advisories have been issued
along/east of I-95 and back into central Virginia through 8 PM
given these higher heat indices. Areas further to the west have
more questionable temperature forecasts given the approach of
afternoon convection.


KEY MESSAGE 2...A risk of severe thunderstorms and flash
flooding exists through Monday.

An active weather pattern continues with the latest convective
and hydrologic outlooks highlighting risk areas over the Mid-
Atlantic. Starting with today, the Storm Prediction Center (SPC)
has placed all areas east of the Alleghenies within a Slight
Risk, with a Marginal Risk for this mountain range. Looking at
the flash flooding potential, all areas north of I-64 are
currently in a Slight Risk. For those with outdoor plans today,
ensure to keep an eye on the sky and have multiple ways to
receive National Weather Service alerts.

With the longstanding mid/upper ridge having buckled on the
northern end, an array of impulses are able to work their way
across the hot and humid air mass. While convection is likely to
initiate across the terrain first, other mesoscale features will
need close attention as well. Most notably, these would include
river and bay breezes, but also a multitude of outflows laid out
by previous convection. Although forecast instability is not as
high as yesterday/Independence Day, the 2,000 to 3,000 J/kg of
mixed-layer CAPE should be plenty sufficient to ignite
afternoon/evening convection. This is accompanied by marginal
0-6 km vertical shear which is around 15 to 20 knots. However,
moisture-laden downdrafts will have access to a very deep and
well mixed boundary layer. As downdraft CAPE values range from
1,000 to 1,300 J/kg, these should support ample downburst
potential. Instability may be slow to fully be exhausted so
convection likely festers into the overnight hours as well.

On the hydrologic side, multiple rounds of storms are expected
which will increase the risk of flash flooding. While the best
high-resolution signal for heavier rainfall is just north of the
Mason-Dixon Line, this could easily seep southward to the I-70
corridor. Will monitor the situation for any needed Flood
Watches.

For Monday, a slow moving frontal system accompanying the
stagnant upper trough will yield another day of active weather.
The better instability profiles begin to shift south of I-66
where the SPC features a Marginal Risk. Further, the Weather
Prediction Center has a Slight Risk for flash flooding from the
Blue Ridge eastward. Well above average precipitable water
values (1.75 to 2.25 inches) combined with repeated convection
and slow cell motions will aid in such a risk. Of course this
will also be driven by how much rainfall occurs over previous
days. Although the region remains in drought, this may only
limit flash flood potential for so long.


KEY MESSAGE 3...More seasonable conditions return by mid/late
week.

The work week ahead starts off with cooler temperatures than the
way July started. The previously mentioned frontal zone begins
to pull south of the area on Tuesday. This eventually shifts the
more active weather and higher moisture content down toward the
Carolinas. This sets the stages for a more seasonable summertime
pattern. While high temperatures are largely confined to the 80s
through Wednesday, some warm up is possible late in the week.
Overnight lows each night will mainly range from the 60s into
the low 70s. Some diurnal afternoon/evening convection is
possible each day, particularly as modest impulses track
eastward within the weaker mid-level flow. Details are somewhat
fuzzy at this time given the rather non-descript flow field.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Wind fields remain on the weaker side today with
afternoon/evening convection looking likely again. PROB30 groups
have been advertised at all TAF sites generally between
19Z-02Z. Restrictions would likely accompany any thunderstorms
during this period of interest. There is a signal for storms to
persist later into the evening and night. Thus, additional
periods of sub-VFR conditions are certainly possible.

Monday presents one more day of more widespread showers and
thunderstorms. This comes with a shift to mainly easterly flow
as a frontal system meanders about the area. Some restrictions
are possible at times as storms form during peak heating.
Improvements become more likely toward mid-week with mainly
northeast to easterly winds. These eventually shift over to
southwesterly by Thursday as the weather may turn more active.

&&

.MARINE...
While summertime synoptic gradients will limit the need for
Small Craft Advisories, daily convection and the associated
outflow boundaries should make for hazardous marine conditions
at times. In particular, the weather looks more active through
Monday night with numerous showers and thunderstorms expected
each afternoon and evening. Thus, Special Marine Warnings will
be needed at times so boaters should certainly plan for
deteriorating conditions. Always have multiple ways to receive
weather alerts while out on the waters.

Convective chances slowly decrease toward mid-week as a frontal
zone sags toward the Carolinas.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Heat Advisory until 8 PM EDT this evening for DCZ001.
MD...Heat Advisory until 8 PM EDT this evening for MDZ008-011-013-
     014-016>018-504-506-508.
VA...Heat Advisory until 8 PM EDT this evening for VAZ037>039-050-
     051-053>057-502-527.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...BRO/DHOF
AVIATION...BRO/DHOF
MARINE...BRO/DHOF