Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

998
FXUS61 KLWX 090700
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
300 AM EDT Tue Jun 9 2026

.WHAT HAS CHANGED...
Stratus remain persistent about 20 to 30 miles either side of
the Blue Ridge and Catoctin Mountains early this morning. The
extent of cloud cover and therefore how warm we get the next 12
to 24 hours is a bit uncertain.

&&

.KEY MESSAGES...
- 1) High pressure brings near normal temperatures today.

- 2) Hot, humid conditions and scattered thunderstorms return
  late this week with a threat for strong storms.

&&

.DISCUSSION...
KEY MESSAGE 1...High pressure brings near normal temperatures
today.

Clouds (stratus) remain rather persistent between I-95 and I-81
early this morning in light onshore flow with high pressure to
the east of the area.

The high will drift east off the Mid-Atlantic coast today while
a shortwave trough approaches from the west. There will likely
be a lot of mid and high level clouds through the day even
if/when stratus scatters out. Combined with the residual
airmass from the offshore high, temperatures in most places will
be limited to the low to mid 80s, with dew points only
gradually climbing through the day. The shortwave may combine
with orographic lift and some weak instability to produce a few
showers and thunderstorms across the Allegheny Mountains during
the afternoon.

Some guidance has a bit strong low-level WAA in the vicinity of
an approaching warm front tonight, so bumped up PoPs slightly. A
few downpours can`t be ruled out, but the probability of
hazardous weather overnight is pretty low.

KEY MESSAGE 2...Hot, humid conditions and scattered thunderstorms
return late this week with a threat for strong storms.

A warm front will lift across the area through Wednesday. There
might be a bit of subsidence behind the wave Wednesday morning,
but continued moisture advection will likely result in a good
deal of cloud cover and possibly some showers. The amount of
cloud cover may make the difference as to whether temperatures
stay in the 80s or top 90. It will definitely be more humid
though, and some steeper lapse rates aloft may result in some
notable instability building by afternoon. Forcing mechanisms
remain in question, but most guidance has some potential for
more showers and thunderstorms. Shear will be modest, but can`t
totally rule out some stronger storms.

Low-level southwesterly flow will advect a very hot and humid
airmass into the area for the end of the week, with temperatures
climbing into the 90s and dewpoints reaching into the upper 60s and
lower 70s. This will result in heat indices climbing into the upper
90s to low 100s on both Thursday and Friday afternoon.

Upper-level ridging is expected to build overhead on Thursday,
with several models also showing a shortwave disturbance passing
through the top of the ridge. How this disturbance evolves will
have a large impact on our forecast locally. If the disturbance
passes through early in the day, we could have large scale
subsidence and relatively low coverage of showers and
thunderstorms. If it were to approach at peak heating, we could
have a much greater coverage of thunderstorms. Upstream
convection will likely have a large impact on how that
disturbance evolves, so confidence in the forecast details on
Thursday is lower than normal. What models are in good agreement
about is that the background environment will be highly
unstable (CAPE values likely in excess of 3000 J/kg). There will
also be enough dry air in the mid levels to support strong
downdrafts (DCAPE in excess of 1000 J/kg), and just enough shear
(around 20 kt) to give storms some weak organization. Such an
environmental setup is common in many of our more impactful
summer severe thunderstorm events. As a result, there appears to
be a conditional threat for severe thunderstorms on Thursday.
That threat for severe thunderstorms may continue on Friday as a
shortwave disturbance passes to our northwest through the Great
Lakes causing the upper ridge to break down and a surface cold
front to approach from the northwest. With greater synoptic
scale forcing, confidence in the occurrence of storms is higher
on Friday, but instability might be slightly less. Machine
learning guidance is very bullish on the severe thunderstorm
threat for both Thursday and Friday. We will continue to monitor
this potential threat over the upcoming days.

A cold front will move through Friday night, advecting drier low-
level (dewpoints dropping to around 60) and mid-level air into the
region. While it will still be hot, conditions are expected to stay
dry during the day Saturday. Forecast uncertainty begins to
increase substantially by Sunday.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Some MVFR CIGs appear likely at CHO/MRB until 14Z-16Z.
Otherwise, VFR conditions are expected with southerly winds. A
few gusts could reach 20 kt this afternoon. A warm front will
lift through the area tonight into Wednesday. While the exact
details are uncertain, there may be some sub-VFR ceilings and
scattered showers during this time. Some thunderstorms are also
possible Wednesday.

Prevailing VFR conditions are expected on both Thursday and Friday,
but temporary restrictions may occur either afternoon as
thunderstorms move through. Winds will generally be out of the
southwest on Thursday, and then south on Friday.

VFR conditions with light NW winds are anticipated Saturday.

&&

.MARINE...
A prolonged period of southerly flow/channeling brings more
gusty conditions this afternoon through Wednesday evening,
likely peaking this evening. Some showers or thunderstorms may
reach the waters late tonight, with a greater chance developing
Wednesday (especially in the afternoon and evening).

Sub-SCA level winds are expected on both Thursday and Friday. Winds
will generally be out of the southwest on Thursday, and then out of
the south on Friday. Special Marine Warnings may be needed on both
Thursday and Friday afternoon as thunderstorms move over the
waters. Sub-SCA northwest winds and drier conditions Saturday.

&&

.TIDES/COASTAL FLOODING...
A somewhat prolonged period of southerly flow will result in
rising tidal anomalies through Wednesday night. The typically
more aggressive guidance (CBOFS, SFAS) shows potential for solid
minor flooding at Annapolis , with minor flooding possible
along other vulnerable shoreline areas (Havre de Grace and
Alexandria, for example).

The higher guidance may be warranted in this case given onshore
flow through tonight pushing water into the Chesapeake Bay,
then southerly flow holding it/pushing it northward into our
neck of the woods through mid week.

Despite the favorable flow pattern, relatively lower
astronomical tides due to a third quarter/waning gibbous today
and relatively modest wind magnitudes should keep the threat for
moderate tidal flooding low.

&&

.CLIMATE...
Temperatures are expected to soar to as much as 15 to 20 degrees
above normal Thursday and Friday. This approaches or exceeds
daily record values at some sites.

Below is a list of record daily high and warm low temperatures
for June 11th and 12th (Thursday and Friday).

=================================================================
            June 11th Record Daily Highs and Warm Lows
=================================================================
Site            Record High                 Record Warm Low
DCA          101 F (set in 1911)      74 F (set in 2020 +6 others)
IAD           95 F (set in 2016)           72 F (set in 2005)
BWI           99 F (set in 1911)           75 F (set in 1914)
DMH          100 F (set in 1984)           79 F (set in 1984)
NAK           96 F (set in 2000)           79 F (set in 1973)
HGR           97 F (set in 1911)           73 F (set in 2005)
MRB          101 F (set in 1911)      71 F (set in 1927 and 1922)
CHO           99 F (set in 1911)           76 F (set in 2020)

=================================================================
            June 12th Record Daily Highs and Warm Lows
=================================================================
Site            Record High                 Record Warm Low
DCA     95 F (set in 2017 +6 others)       77 F (set in 2015)
IAD           96 F (set in 1986)           72 F (set in 1986)
BWI     96 F (set in 1986 and 1914)        77 F (set in 1947)
DMH     96 F (set in 2025 +2 others)  77 F (set in 2017 and 2015)
NAK           98 F (set in 1914)      77 F (set in 2000 and 1973)
HGR     92 F (set in 2017 +5 others)  71 F (set in 2010 +5 others)
MRB     97 F (set in 1938 and 1933)        73 F (set in 1914)
CHO           98 F (set in 1914)      72 F (set in 1947 +2 others)

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 10 PM EDT
     this evening for ANZ530-535-536-538-542.
     Small Craft Advisory from 4 PM this afternoon to noon EDT
     Wednesday for ANZ531>533-537-539>541.
     Small Craft Advisory from 4 PM this afternoon to 6 PM EDT
     Wednesday for ANZ534-543.

&&

$$

DISCUSSION...ADS/DHOF/KJP/CPB
AVIATION...ADS/DHOF/KJP
MARINE...ADS/DHOF/KJP
TIDES/COASTAL FLOODING...DHOF
CLIMATE...DHOF