Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

279
FXUS61 KLWX 191913
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
313 PM EDT Wed Aug 19 2026

.WHAT HAS CHANGED...
A Small Craft Advisory was issued for the southern portions of
the Chesapeake Bay for tomorrow afternoon as southerly winds
gust around 20 knots. The severe threat for Thursday continues
with SPC having a portion of the forecast area in a slight risk
for severe weather.

&&

.KEY MESSAGES...
- 1) Shower and thunderstorm chances return on Thursday
with precipitation chances lingering Friday and Saturday.


- 2) Numerous showers and thunderstorms Saturday with lingering
 showers Sunday. Turning cooler and dry next week.

&&

.DISCUSSION...

KEY MESSAGE 1...Shower and thunderstorm chances return on Thursday
with precipitation chances lingering Friday and Saturday.

An isolated shower cannot be ruled out this afternoon, mainly over
the Shenandoah Valley although departing high pressure leads to
primarily dry conditions across the forecast area. Cloud cover
increases overnight as a cold front approaches from the Great Lakes
region. To the south, a stalled boundary draped over the Carolinas
drifts north as waves of low pressure traverse along it.
Precipitation chances increase overnight with showers possible
Thursday morning.

Convective chances increase throughout the day on Thursday as
shortwave energy tracks towards the mid-atlantic from the Ohio
river valley. There is uncertainty regarding the strength of
storms due to morning precipitation and location of the fronts
coinciding with peak daytime heating. Best chances for strong
to severe thunderstorms is along and east of the I-95 corridor
where the best conditions overlap. Here, SPC has a slight risk
for severe weather with damaging wind gusts, large hail, and a
brief tornado possible. Effective shear nearing 40 knots
combined with CAPE 2000 J/kg allows discrete cells to become
more organized into a line as storms track eastward. Confidence
is highest along and east of the I-95 corridor tomorrow
afternoon and into early the evening.

In addition to the severe threat, PWATS nearing and exceeding 2"
lead to an isolated flooding threat. Storms will be capable of
producing heavy rainfall but progressive storm motions should
limit flooding threat to sensitive areas.

KEY MESSAGE 2...Numerous showers and thunderstorms Saturday
with lingering showers Sunday. Turning cooler and dry for next
week.

The longwave pattern is forecast to amplify significantly this
weekend into next week as trough digs across the Great Lks and OH
Valley. This will drive a pair of cold fronts across the area Sat
and Sun providing focus for showers and thunderstorms. Saturday
looks like the more unstable day as we remain in WSW flow aloft and
with better forcing ahead of the trough axis.  By Sunday, the first
cold front should have pushed the deep moisture and instability to
the south limiting the coverage and intensity of showers while the
trough axis moves overhead limiting the upper level forcing.

As trough axis shifts east of the area Sunday night, expect a cooler
and drying trend to start the new work week.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Winds remain out of the west/southwest this afternoon with
prevailing VFR conditions expected. Cloud cover and precipitation
chances increase across the terminals overnight although primarily
VFR conditions are expected through early Thursday morning. Morning
convection may impact MRB as showers and thunderstorms track across
western MD/eastern panhandle of WV. Showers and thunderstorms impact
the terminals Thursday afternoon with restrictions likely during
heavy precipitation. Highest chances for strong to severe
thunderstorms remains along and east of I-95 terminals. After
precipitation moves out of the area, low ceilings are possible
Thursday night into Friday.

Sct convection Sat through Sun.

&&

.MARINE...
Winds remain below Small Craft Advisory criteria through
Thursday morning. A Small Craft Advisory is in effect for the
southern Chesapeake Bay tomorrow afternoon. SMWs are possible
Thursday afternoon as strong to severe thunderstorms track
across the waters. Otherwise, non hazardous marine weather is
expected through the end of the week.

&&

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

&&

$$

DISCUSSION...AVS/LFR
AVIATION...AVS/LFR
MARINE...AVS/LFR