Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

377
FXUS61 KLWX 080759
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
359 AM EDT Wed Jul 8 2026

.WHAT HAS CHANGED...
The forecast largely remains on track with any early morning
showers likely falling short of any flood threat given their
disorganized state. Thursday still appears to become more active
as Marginal Risks are indicated for both severe weather and
flash flooding.

&&

.KEY MESSAGES...
- 1) Brief cool down before a warm up through Friday, which is
  accompanied by daily shower and thunderstorm chances.

- 2) Turning cooler with less humidity over the weekend, but
  daily storm chances persist.

&&

.DISCUSSION...
KEY MESSAGE 1...Brief cool down before a warm up through Friday,
which is accompanied by daily shower and thunderstorm chances.

The early week frontal system has now pushed off to the south
with a location near the Virginia/North Carolina border. While
the area is post-frontal in nature, moisture content remains
high as noted by the upper 60s to low 70s dew points.
Additionally, this is also supported by the elevated
precipitable water values, averaging around 1.75 to 2.00 inches.

Showers continue to develop in this environment given
sufficient most-unstable CAPE (MUCAPE) which is uncapped. The
06Z RAP objective analysis shows anywhere from 250 to 750 J/kg
of MUCAPE across the area. While the radar presentation of these
cells is rather disorganized, they are efficient rainfall
producers. For example, personal weather stations showed
anywhere between 1 and 2 inches of rainfall in an hour or two along
the western shoreline of St. Mary`s County. Given high flash
flood guidance values, any hydrologic impact is minimal.

Aside from this sporadic shower development, a broad area of low
stratus have overspread most of the region. Some of these thick
low clouds have evolved into patchy fog, especially over the
Shenandoah Valley and central Virginia Piedmont. Fog could
become locally dense in spots so drivers should be aware of
abrupt reductions in visibility.

Today`s shower and thunderstorm chances will stay mainly west of
U.S. 15. As an upper low initially over western Tennessee should
continue to shear on its eastward approach toward the
Appalachian Mountains. Some added lift with the approach of this
trough will work in conjuction with terrain circulations to aid
in diurnal convective development. Weak shear profiles will
limit any severe threat; however, there is a non-zero flood
threat for locations hit by recent heavy rainfall. The Weather
Prediction Center has maintained a Marginal Risk for excessive
rainfall from the Blue Ridge westward. Overall temperatures
should stay fairly close to yesterday`s numbers. Most can expect
highs in the upper 70s to low 80s, with slightly cooler readings
in the mountains.

Moving toward Thursday, all signs point toward an uptick in
convection across the Mid-Atlantic region. The earlier mentioned
upper trough across Tennessee is likely to push through during
the core heating hours. With 500-mb winds approaching 30 to 35
knots, this will contribute to deep layer shear to around 30
knots. Steep low-level lapse rates are forecast to contribute to
downdraft CAPEs near 1,000 J/kg. This would be supportive for
some degree of damaging wind threat, particularly in the taller
updrafts. As such, the Storm Prediction Center continues to
advertise a Marginal Risk for severe weather on Thursday from
I-81 eastward to the Atlantic coast. A flash flood threat would
accompany any slower moving convection or areas which see repeat
activity.

By Friday, this is likely to mark the warmest day of the week
with high temperatures returning to the low 90s. However, for
early/mid July standards, this is fairly close to climatology.
Further storm chances arise, particularly during the afternoon
to evening hours, as a trailing more pronounced shortwave nears
the region. This system also drives a cold front through by
early in the weekend. Until this occurs, will maintain higher
chances for showers and thunderstorms. While convective-scale
details vary among models, there is certainly a non-zero threat
of flash flooding over the region.


KEY MESSAGE 2...Turning cooler with less humidity over the
weekend, but daily storm chances persist.

On Saturday morning, the longwave pattern indicates a broad
trough will begin to exit the Canadian Maritimes down along the
Mid-Atlantic coast. This brings a slow moving cold front through
the area on Saturday before the system settles over North
Carolina by late in the weekend. Post-frontal northerlies will
bring a gradual downtick in dew points and thus humidity levels.
Depending on how quickly this front tracks through, some shower
chances likely continue across the area for portions of the
weekend. Daily temperatures fall in the post-frontal
environment, generally running around 2 to 5 degrees below
average. Highs each days should be in the low/mid 80s, with 70s
across mountain locales.

Heading into early next week, the synoptic-scale pattern
features a broad ridge over the Four Corners into the Northern
Plains. At the same time, northwesterly flow aloft should occur
off to the east over the northeastern U.S. In this regime, box-
and-whisker temperature plots show near to below average
temperatures for early next week. Heights begin to build toward
the middle of next week as the upstream ridge attempts to expand
eastward. Temperatures likely return to the 90s as this occurs.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
The combination of light onshore flow behind the cold front
coupled with a moist boundary layer has supported low overnight
ceilings. While not all locations have seen ceilings tank as
quickly, the expectation is for the D.C. terminals, as well KCHO
and KMRB to be in IFR conditions. This is expected to hold
through the mid-morning hours before slow but steady
improvements occur. It may take until the mid/late afternoon to
fully return to VFR as low clouds linger in the onshore flow.
Winds gradually shift to south to southeasterly by this evening
before turning calm tonight. Another round of low clouds are
looking likely which would support additional restrictions.

Daily convective chances return to the picture on Thursday and
Friday. This is in response to a series of shortwave troughs
that track in from the west. Convective-driven restrictions are
possible in this environment, particularly during the afternoon
to evening hours. Winds remain southerly on Thursday before
shifting to westerly by Friday.

The next cold front moves through on Saturday which yields a
shift to northerly winds. Some frontal showers may support a few
restrictions before the system moves toward the Virginia/North
Carolina by Sunday. At that point, winds turn more easterly with
mainly VFR conditions expected.

&&

.MARINE...
Typical summertime gradients should keep the marine waters free
of any long-fused hazardous weather products (i.e., Small Craft
Advisories). However, as usual, hazardous boating conditions
will often be driven by convection, strong outflows/gust fronts,
and frequent lightning. Shower and thunderstorm chances increase
on Thursday into Friday as a series of shortwave troughs move in
from the west. Special Marine Warnings will be needed for the
more robust thunderstorm activity. During this period, winds
shift to southerly for Thursday with gusts up to around 10 to 15
knots. Thereafter, winds turn more westerly on Friday with a
slight decrease in gusts.

For the weekend, a cold front tracks through on Saturday which
may support some hazardous marine conditions due to
thunderstorms. Winds will be out of the north before shifting to
easterly for the second half of the weekend. Gusts each day
should top out around 10 to 15 knots.

&&

.TIDES/COASTAL FLOODING...
Light onshore (east to northeast flow) the next couple days
followed by southerly flow will cause rising tides over the next
couple of days. This will likely result in near minor flooding
of vulnerable shoreline the second half of this week.

&&

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

&&

$$

DISCUSSION...BRO
AVIATION...BRO
MARINE...BRO
TIDES/COASTAL FLOODING...LWX