Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

194
FXUS61 KLWX 050802
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
402 AM EDT Sun Jul 5 2026

.WHAT HAS CHANGED...
Have added more patchy fog/reduced visibility across the D.C.
and Baltimore hubs given firework smoke nearby. Issued Heat
Advisories from 10 AM until 8 PM this evening for the I-95
corridor and back into central Virginia. Otherwise, the national
center outlooks continue to advertise a risk of severe weather
and flash flooding through Monday.

&&

.KEY MESSAGES...
- 1) Remaining hot today with Heat Advisories in effect along
  the I-95 corridor and back into central Virginia.

- 2) A risk of severe thunderstorms and flash flooding exists
  through Monday.

- 3) More seasonable conditions return by mid/late week.

&&

.DISCUSSION...
KEY MESSAGE 1...Remaining hot today with Heat Advisories in
effect along the I-95 corridor and back into central Virginia.

Given the degree of heat and humidity in the atmosphere,
convection has persisted well into the overnight hours. However,
there has been a downtick over the last few hours as echoes
weaken just south of I-66. While most unstable CAPE (MUCAPE)
values still average around 500 to 750 J/kg, convective
inhibition has increased quite markedly. Although some showers
could persist toward daybreak, expect a largely dry finish
heading into the morning.

Relative to previous nights, current temperatures are on the
order of 5 to 10 degrees cooler owing to earlier convection and
rain-cooled air. Most locations are holding steady in the upper
60s to mid 70s which closely match dew points. Areas of patchy
fog will develop within the decoupled boundary layer, especially
in areas that saw recent rainfall. Additionally, some pockets
of further reductions in visibility are noted around Washington,
D.C. and Baltimore given residual firework smoke/aerosols. This
may linger into the morning before nocturnal inversions mix out
a couple hours after sunrise.

Looking ahead, expect another hot day given continued above
average mid/upper heights. However, the forecast does keep
readings below the century mark with the warmer spots being east
of the Blue Ridge (mid/upper 90s). Given ample low-level
moisture, dew points remain elevated which will carry heat
indices into the 100 to 107 degree range. Heat Advisories have
been issued along/east of I-95 and back into central Virginia
for 10 AM through 8 PM given these higher heat indices. Areas
further to the west have more questionable temperature forecasts
given the approach of afternoon convection.


KEY MESSAGE 2...A risk of severe thunderstorms and flash
flooding exists through Monday.

An active weather pattern continues with the latest convective
and hydrologic outlooks highlighting risk areas over the Mid-
Atlantic. Starting with today, the Storm Prediction Center (SPC)
has placed all areas east of the Alleghenies within a Slight
Risk, with a Marginal Risk for this mountain range. Looking at
the flash flooding potential, all areas north of I-64 are
currently in a Slight Risk. For those with outdoor plans today,
ensure to keep an eye on the sky and have multiple ways to
receive National Weather Service alerts.

With the longstanding mid/upper ridge having buckled on the
northern end, an array of impulses are able to work their way
across the hot and humid air mass. While convection is likely to
initiate across the terrain first, other mesoscale features will
need close attention as well. Most notably, these would include
river and bay breezes, but also a multitude of outflows laid out
by previous convection. Although forecast instability is not as
high as yesterday/Independence Day, the 2,000 to 3,000 J/kg of
mixed-layer CAPE should be plenty sufficient to ignite
afternoon/evening convection. This is accompanied by marginal
0-6 km vertical shear which is around 15 to 20 knots. However,
moisture-laden downdrafts will have access to a very deep and
well mixed boundary layer. As downdraft CAPE values range from
1,000 to 1,300 J/kg, these should support ample downburst
potential. Instability may be slow to fully be exhausted so
convection likely festers into the overnight hours as well.

On the hydrologic side, multiple rounds of storms are expected
which will increase the risk of flash flooding. Radar imagery
over the last 6 hours has also shown a tendency of storms to
align on old outflows. While the best high-resolution signal for
heavier rainfall is just north of the Mason-Dixon Line, this
could easily seep southward to the I-70 corridor. Will monitor
the situation for any needed Flood Watches.

For Monday, a slow moving frontal system accompanying the
stagnant upper trough will yield another day of active weather.
The better instability profiles begin to shift south of I-66
where the SPC features a Marginal Risk. Further, the Weather
Prediction Center has a Slight Risk for flash flooding from Blue
Ridge eastward. Well above average precipitable water values
(1.75 to 2.25 inches) combined with repeat convection and slow
cell motions will aid in such a risk. Of course this will also
be driven by how much rainfall occurs over previous days.
Although the region remains in drought, this may only limit
flash flood potential for so long.


KEY MESSAGE 3...More seasonable conditions return by mid/late
week.

The work week ahead starts off with cooler temperatures than the
way July started. The previously mentioned frontal zone begins
to pull south of the area on Tuesday. This eventually shifts the
more active weather and higher moisture content down toward the
Carolinas. This sets the stages for a more seasonable summertime
pattern. While high temperatures are largely confined to the 80s
through Wednesday, some warm up is possible late in the week.
Overnight lows each night will mainly range from the 60s into
the low 70s. Some diurnal afternoon/evening convection is
possible each day, particularly as modest impulses track
eastward within the weaker mid-level flow. Details are somewhat
fuzzy at this time given the rather non-descript flow field.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...

Any early morning convection has finally begun to decay. Some
reduced visibilities remain around KDCA and KBWI owing to
firework smoke being trapped in the stable boundary layer.
Improvements should occur once vertical mixing occurs shortly
after sunrise. Wind fields remain on the weaker side today with
afternoon/evening convection looking likely again. PROB30 groups
have been advertised at all TAF sites generally between 19Z-02Z.
Restrictions would likely accompany any thunderstorms during
this period of interest. There is a signal for storms to persist
later into the evening and night. Thus, additional periods of
sub-VFR conditions are certainly possible.

Monday presents one more day of more widespread showers and
thunderstorms. This comes with a shift to mainly easterly flow
as a frontal system meanders about the area. Some restrictions
are possible at times as storms form during peak heating.
Improvements become more likely toward mid-week with mainly
northeast to easterly winds. These eventually shift over to
southwesterly by Thursday as the weather may turn more active.

&&

.MARINE...
While summertime synoptic gradients will limit the need for
Small Craft Advisories, daily convection and the associated
outflow boundaries should make for hazardous marine conditions
at times. In particular, the weather looks more active through
Monday night with numerous showers and thunderstorms expected
each afternoon and evening. Thus, Special Marine Warnings will
be needed at times so boaters should certainly plan for
deteriorating conditions. Always have multiple ways to receive
weather alerts while out on the waters.

Convective chances slowly decrease toward mid-week as a frontal
zone sags toward the Carolinas.

&&

.CLIMATE...
There is a Significant Heat Risk today (Independence Day). The
numbers below aren`t a forecast, but rather a reference for
historical context for comparison. Latest forecast:
weather.gov/lwx. A number of daily records have been broken at
the local airports the past couple of days (July 1-3).

==================================================================
                    *** ALL-TIME RECORD HIGHS ***
==================================================================
Baltimore                 107 (set on Jul 10, 1936)
Washington                106 (set on Jul 20, 1930 + Aug 06, 1918)
Sterling-Dulles Airport   105 (set on Jul 22, 2011)
Baltimore Downtown        108 (set on Jul 07, 2012 + Jul 22, 2011)
Annapolis                 106 (set on Aug 06, 1918)
Hagerstown                105 (set on Jul 14, 1954)
Martinsburg               112 (set on Jul 11, 1936)
Charlottesville           107 (set on Sep 07, 1954 + 3 other times)

==================================================================
                  *** ALL-TIME RECORD WARM LOWS ***
==================================================================
Baltimore                  83 (set on Aug 05, 1930 + 2 other times)
Washington                 84 (set on Jul 24, 2011 + 2 other times)
Sterling-Dulles Airport    79 (set on Aug 08, 2007)
Baltimore Downtown         88 (set on Jul 22, 2011 and Jul 10, 1993)
Annapolis                  92 (set on Jul 07, 1994)
Hagerstown                 86 (set on Jun 15, 1899)
Martinsburg                86 (set on Jul 21, 1930)
Charlottesville            85 (set on Aug 07, 1918)

==================================================================
                  *** JULY MONTHLY RECORD HIGHS ***
==================================================================
Baltimore                 107 (set on Jul 10, 1936)
Washington                106 (set on Jul 20, 1930)
Sterling-Dulles Airport   105 (set on Jul 22, 2011)
Baltimore Downtown        108 (set on Jul 07, 2012 + Jul 22, 2011)
Annapolis                 105 (set on Jul 21, 1930 + Jul 02, 1901)
Hagerstown                105 (set on Jul 14, 1954)
Martinsburg               112 (set on Jul 11, 1936)
Charlottesville           107 (set on Jul 10, 1936 + Jul 20, 1930)

==================================================================
                 *** JULY MONTHLY RECORD WARM LOWS ***
==================================================================
Baltimore                  83 (set on Jul 21, 1930)
Washington                 84 (set on Jul 24, 2011 + 2 other times)
Sterling-Dulles Airport    78 (set on Jul 24, 2010 + Jul 08, 2010)
Baltimore Downtown         88 (set on Jul 22, 2011 + Jul 10, 1993)
Annapolis                  92 (set on Jul 07, 1994)
Hagerstown                 83 (set on Jul 24, 2010)
Martinsburg                86 (set on Jul 21, 1930)
Charlottesville            84 (set on Jul 22, 1930)

-----------------------------------------------------------------

             Number of Consecutive Days Max Temp >=100
Area (obs site)              Longest Streaks

------------------------------------------------------------------
Baltimore (BWI)          4 days  July 14-17,2024 & July 19-22,1930
Washington (DCA)         4 days  July 14-17, 2024 & July 5-8, 2012
Sterling-Dulles (IAD)    2 days  July 7-8, 2012, July 21-22, 2011
                                 July 6-7, 2010, July 16-17, 1997

Baltimore Downtown (DMH) 5 days July 3-7, 2010 & July 7-11, 1993
Annapolis (NAK)          1 day  July 21, 2019, July 7, 2012,
                                July 22, 2011, June 29, 1959

Hagerstown (HGR)         3 days July 5-7, 2010
Martinsburg (MRB)        6 days June 1-6, 1925
Charlottesville (CHO)    5 days July 4-8, 2012



     Period of Record (POR) context...
Area (obs site)              Records since
------------------------------------------------------------------
Baltimore (BWI)                     Jan 1872
Washington (DCA)                    Jul 1872
Sterling-Dulles Airport (IAD)       Jan 1960
Baltimore Downtown (DMH)            Jul 1950
Annapolis (NAK)                     Jan 1894
Hagerstown (HGR)                    Jan 1899
Martinsburg (MRB)                   Jan 1891
Charlottesville (CHO)               Jan 1893

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for DCZ001.
MD...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for MDZ008-011-013-014-016>018-504-506-508.
VA...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for VAZ037>039-050-051-053>057-502-527.
WV...None.
MARINE...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for ANZ530.

&&

$$

DISCUSSION...BRO
AVIATION...BRO
MARINE...BRO