Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

233
FXUS61 KLWX 220757
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
357 AM EDT Wed Jul 22 2026

.WHAT HAS CHANGED...
Confidence is slowly increasing on where the highest shower and
thunderstorm chances will be this afternoon and evening. Small
Craft Advisory were issued for tonight into Thursday morning.
Timing of the next chance of rain remains uncertain for this
weekend into early next week.

&&

.KEY MESSAGES...
- 1) A few strong to severe thunderstorms are possible from
  central Virginia to southern Maryland this afternoon.

- 2) Below average temperatures and mainly dry conditions are
  expected Thursday through Saturday.

&&

.DISCUSSION...
KEY MESSAGE 1...A few strong to severe thunderstorms are
possible from central Virginia to southern Maryland this
afternoon.

The cold front appears to be just southeast of Lake Erie as of 3
AM with the upper level trough axis across the eastern Great
Lakes down into the Ohio Valley. The heaviest rain has exited
the area. Convection that has been developing west of the
Appalachians has been dissipating as it crosses the ridge into
more stability and encounters downsloping flow. A few areas of
light showers/sprinkles still exist though. With clearing skies
and relatively light winds, a few patches of fog could form, but
it is unlikely to be widespread.

A prefrontal trough will switch winds to westerly through much
of the day before northerly winds bring the true airmass change
tonight. The cold front likely overtakes the trough at some
point but will temporarily stall this afternoon, likely
extending across central Virginia to southern Maryland. Dew
points will remain in the 70s in this area, supporting some
instability to go along with the wind shear provided by the
upper trough. Scattered to numerous showers and thunderstorms
are forecast along and southeast of the front, although there
remains some uncertainty in coverage and intensity. Given the
shear in place, there is some potential for severe
thunderstorms, with damaging winds being the primary threat.
Thunderstorms may also be repetitive along the slow moving
front, but the expected fast individual storm motions will
likely preclude any flood threat.

The front will drop south of the area this evening, but an area
of low pressure may ride along it. This could result in
additional showers spreading across central Virginia and
southern Maryland through the night.

In terms of temperatures, highs today will be in the 70s to
lower 80s west of I-81 and mid to upper 80s to the east.
Lows tonight will drop into the 50s and 60s, and some of the
sheltered high elevation valleys could reach the 40s.


KEY MESSAGE 2...Below average temperatures and mainly dry
conditions are expected Thursday through Saturday.

A sprawling area of high pressure will build to our north for
Thursday and Friday, before shifting off the New England
Coastline on Saturday. Northerly flow ahead of the approaching
high will advect a much cooler and drier airmass into the region
for Thursday. Well below normal temperatures and dewpoints are
forecast for late July, with high temperatures only in the upper
70s/low 80s. Dewpoints in the 50s will also make it feel much
less humid than is typical for July. Mostly sunny skies will
accompany the well below normal temperatures/dewpoints.
Temperatures will stay well below normal for Friday and Saturday
within easterly flow. Some moisture could be drawn northward
from the stalled frontal zone across the southeastern states
during this time. The current forecast has some low rain chances
both days, mainly in southern portions of the CWA and along the
Allegheny Mountains.

Both temperatures and dewpoints begin to rise again on Sunday
as flow turns southerly, with highs in the mid to upper 80s and
dewpoints in the 60s. The return of higher dewpoint air should
lead to slightly greater chances for afternoon/evening showers
and thunderstorms, but most locations will likely still stay
dry.

Forecast confidence decreases substantially by Monday and Tuesday,
but chances for showers and thunderstorms may further increase as
multiple shortwave disturbances move through in northwesterly flow
aloft. Depending on how the forecast details evolve, there could be
a conditional threat for severe thunderstorms on either Monday or
Tuesday.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Convection has departed, but there are still some patchy
sprinkles, and the cold front still lurks well to the northwest.
There has been a lot of variation between models whether any fog
or low clouds form through dawn, so did not forecast anything
below MVFR for now. Should anything develop, it should clear
quickly after sunrise as winds turn westerly. The front sags
slowly across the area today. Some showers and thunderstorms may
form ahead of the front this afternoon, potentially affecting
CHO and DCA. The greatest coverage may be just to the south
though. A wave of low pressure may ride along the front this
evening and could push some additional showers toward CHO and
DCA, but most of the lower ceilings will likely remain to the
south. Winds will turn northerly this evening.

Prevailing VFR condtions are expected most of the time between
Thursday through Sunday. There may be some lower ceilings at
times this weekend in onshore flow, but confidence is low. Winds
will generally be out of the north on Thursday, east on Friday,
and southeast on Saturday and Sunday.

&&

.MARINE...
It appears earlier storms have stabilized the atmosphere, so
portions of the existing Small Craft Advisory may be cancelled
early. Some continuation of advisory conditions is expected into
the day on the wider mid-bay waters. Additional strong to
perhaps severe thunderstorms may develop ahead of a cold front
this afternoon and evening across mainly southern Maryland.

A pressure surge and accompanying shift to northerly winds will
push across the waters this evening. Small Craft Advisories have
been issued for tonight into Thursday morning along the bay.

Thereafter, sub-SCA level winds are expected Thursday afternoon
through Sunday. Winds will generally be out of the north on
Thursday, east on Friday, and southeast on Saturday and Sunday.

&&

.TIDES/COASTAL FLOODING...
Anomalies remain between 0.5-1 foot this morning. Havre de
Grace may approach minor flood stage this morning but should
remain below. Water levels will drop as a cold front passes
later today.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 8 AM EDT this morning for MDZ008.
     Small Craft Advisory from 9 PM this evening to 8 AM EDT
     Thursday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for ANZ530-
     531-539.
     Small Craft Advisory from 9 PM this evening to 8 AM EDT
     Thursday for ANZ530>532-539-540.
     Small Craft Advisory until noon EDT today for ANZ532-533-
     540>542.
     Small Craft Advisory from midnight tonight to 11 AM EDT
     Thursday for ANZ533-534-537-541-543.
     Small Craft Advisory until 6 PM EDT this evening for ANZ534-
     537-543.
     Small Craft Advisory until 4 AM EDT early this morning for
     ANZ536.

&&

$$

DISCUSSION...ADS/KJP
AVIATION...ADS/KJP
MARINE...ADS/KJP