Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

490
FXUS61 KLWX 210059
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
859 PM EDT Thu Aug 20 2026

.WHAT HAS CHANGED...
Severe Thunderstorm Watches and Tornado Watches have been allowed to
expire. A few spotty showers leftover this evening with lower
humidity and cooler temps tonight into Friday.

&&

.KEY MESSAGES...
- 1) Quieting down tonight into Friday with lowering humidity and
cooler temperatures.

- 2) Thunderstorm chances increase Friday night and continue
  through Sunday. Lowering humidity and drier conditions early
  next week.

&&

.DISCUSSION...

KEY MESSAGE 1...Quieting down tonight into Friday with lowering
humidity and cooler temperatures

Severe Thunderstorm Watches and Tornado Watches have been allowed to
expire early as the severe threat diminishes. The line of
thunderstorms that have prompted the watches earlier this evening
have since pushed south into the northern neck of VA and the lower
Delmarva. Our area really dodged the brunt of the severe weather due
to poor lapse rates, low DCAPE, and earlier cloud cover across the
region. Locations such as southeast PA, Delaware, and the Eastern
Shore of Maryland were not as lucky with multiple reports of damage
due to earlier tornado warned storms.

Expect calmer conditions tonight with just a few residual
showers and the cold front sags south and east into the region.
Skies will trend partly to mostly cloudy with lowering ceilings
east of the Blue Ridge on light north to northwest flow.
Humidity will drop as well along with temperatures. Lows tonight
will range from the upper 50s over the mountains to low to mid
60s in and around the Baltimore/DC metros.

Friday will bring a lull in the shower and thunderstorm activity as
the front stalls south and east of the region. Expect partly to
mostly cloudy skies with highs in the mid 70s and low 80s. With the
front nearby expect an isolated shower or thunderstorm over terrain
or down toward the I-64 corridor Friday afternoon. More scattered to
numerous showers and embedded thunderstorms look to hold off until
Friday night and Saturday as the front lifts north and an area of
low pressure develops off the VA Tidewater/lower Delmarva region.

KEY MESSAGE 2... Thunderstorm chances increase Friday night and
continue through Sunday. Lowering humidity and drier conditions
early next week.

By Friday night into Saturday, a surface low develops near the VA
Tidewater and moves northeast along the coast/front. Also, another
mid/upper wave approaches from the west. Depending on the exact
track and strength of each of these features, and how they interact,
this could bring higher potential for showers and thunderstorms to
the region. Enhanced flow downstream of a deepening trough over the
Midwest results in an environment conditionally favorable for strong
storms if enough instability is realized.

Current model guidance has continued with the trend of the upper
trough moving through more slowly on Sunday, thus leading to the
increased in chances for strong to severe thunderstorms since higher
instability will be realized. AI probabilities (10-30 percent)
continue to trend upward with highest chances along and west of the
Blue Ridge Sunday afternoon.

In the wake of potential showers and thunderstorms on Sunday,
surface high pressure builds overhead through Tuesday. Temperatures
Monday and Tuesday will top out in the 70s to low 80s with low
relative humidity values expected. Precipitation chances and
humidity return on Wednesday as a stalled boundary to the south
shifts northward.


&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Overall looking at quiet weather conditions overnight with pockets
of SCT-BKN low ceilings, especially in areas east of the Blue Ridge
and south of I-66/US-50 as the front sags south/east. Sporadic 15-20
kt gusts will continue along the front as it continues south and
east through 02z/10pm. A residual shower or two cannot be ruled out,
with most terminals remaining dry. Some patchy fog may be noted out
toward MRB, CHO, and SHD early Friday morning prior to 12z/8am with
vsbys between 3-6SM. More widespread mountain valley fog is
expected west of these terminals. A period of low ceilings
IFR/MVFR (1-3 kft) is possible between 03-14z across the
corridor terminals as well as CHO given the front nearby.
Ceilings look to improve mid to late Friday morning into the
afternoon due a brief lull in the wake of the front.

Showers and thunderstorms do return to the terminals from the south
beyond 3-6z/Saturday as an area of low pressure develops along the
coast and pushes up along the stalled front nearby. Coverage of
showers and thunderstorms will be scattered to numerous throughout
the day with temporary restrictions at times. More organized severe
weather is possible by Sunday. Winds will be out of the north and
northwest Friday and Saturday at less than 15 kts.

Northwesterly winds gust up to 25 knots on Sunday at MRB with
eastward terminals blowing around 10 knots in the afternoon. Showers
and thunderstorms are possible, leading to flight restrictions
across all terminals. Winds shift to westerly on Monday and Tuesday
with VFR conditions expected.

&&

.MARINE...

SCAs will continue for all waters through at least 4z/12am as a cold
front sags south and east. Any residual convection should exit the
lower waters here prior to 130z/930pm. Expect improving marine
conditions overnight with areas of fog and low clouds. Winds will be
out of the north and northwest at less than 15 kts. Sub-SCA
level conditions are expected Friday with winds still out of
the north/northwest at less than 15 kts. Thunderstorm activity
will be limited with rain chances returning from the south late
Friday night into Saturday morning. More scattered to numerous
showers and thunderstorms are expected Saturday afternoon and
evening. Winds will turn more to the northeast at less than 15
kts.


Northwest winds on Sunday shift to westerly on Monday, remaining
below SCA criteria both days. There is a chance for showers and
thunderstorms on Sunday, although chances are highest west of the
waters. Should storms track over the waters, SMWs are possible.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until midnight EDT tonight for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ530>543.

&&

$$

DISCUSSION...AVS/EST
AVIATION...AVS/EST
MARINE...AVS/EST