Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

725
FXUS61 KLWX 030115
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
915 PM EDT Wed Sep 2 2026

.WHAT HAS CHANGED...
The severe weather threat continues to decrease overnight, but the
threat for thunderstorms remains, especially along and north of I-
66/US-50. Heat Advisories have been issued from 11am to 8pm Thursday
for portions of the eastern WV Panhandle, southern MD, and
northern/central VA.



&&

.KEY MESSAGES...
- 1) Hot temperatures, high humidity, and severe thunderstorm
chances look to continue through Friday.

- 2) Mostly dry conditions and lowering humidity for the Labor
  Day holiday weekend ahead.

&&

.DISCUSSION...
KEY MESSAGE 1...Hot temperatures, high humidity, and severe
thunderstorm chances look to continue through Friday.

The severe weather threat continues to decrease this evening as the
the remnant outflow/backdoor front washes out over the region. A
leftover shower or two has been noted across up across
Washington/Frederick counties, but this activity has gradually
decreased in coverage given the stability in the lower levels.
Scattered to broken mid and high level clouds will remain,
especially points east of I-81 given the washed out boundary nearby.

Overall expecting a lull in any activity through at least 2-3am with
the potential for a secondary round storms dropping south from PA
heading into early Thursday morning. This activity is currently
located up across the Twin Tiers of New York/northeast PA where
numerous severe thunderstorm warnings are in effect. Hi-res guidance
pushes this activity slowly south into areas along and north of I-
66/US-50 between 2am-6am Thursday morning. Guidance varies on
coverage with a focus across northern and central MD compared to
locations further south into Washington DC, southern MD, and
northern VA. At this rate, not looking at any widespread severe
weather with this batch of storms although locally gusty winds,
heavy rainfall, and frequent lightning cannot be ruled out.

The big question is to how this round of morning convection (if it
occurs) plays into what will happen in the afternoon. Current
guidance suggest a scattering of storms originating in and around
the Alleghenies working east as another wave of energy pulses
through. Some of guidance has limited activity east of the mountains
while others have more. General consensus is for convection to pop
toward the mountains and west of US-15 between 11am-2pm before
working east into the metros between 3-9pm. Coverage remains
uncertain given any convective debris from the morning. Even with
that said, expect some organization given 30-35 kts of shear aloft.
Damaging winds will be the primary threat with storms given
increased DCAPE values on the order of 1000-1400 j/kg. Large hail
also cannot be ruled out due to decent lapse rates in the 6-7.5
degree C/km range. As for flooding, an isolated instance or two
cannot be ruled out, especially in urban areas or in the event a
cell backbuilds/trains over a given area. Modeling continues to hold
additional thunderstorm threats Thursday night into Friday although
confidence in this is low pending the timing and placement of the
incumbent cold frontal boundary.

Right now, most of the guidance has a front dropping through the
area either Friday morning into Friday afternoon or Friday afternoon
into Friday night. This would spell continue concerns for severe
weather in locations along and south of I-70/I-68 where instability
may be maximized. The added lift from the front should help with
better coverage and organization of t-storms Friday afternoon and
evening. Damaging winds will once again be the main threat with
storms along with frequent lightning, locally heavy rainfall, and
large hail as secondary concerns.

Storms will have plenty of fuel to work with as highs pushing back
into the low to mid 90s Thursday afternoon. Locations south of I-
66/US-50 and along/east of I-95 could see highs in the mid to upper
90s. Heat indices will range from 100 to 105 degrees for locations
east of the Blue Ridge. Heat Advisories have been hoisted for
portions of northern and central VA, southern MD and the eastern WV
Panhandle where criteria will be met. Baltimore/Washington DC Metros
will be just shy with heat indices likely hovering in the 100-104
degree range. Temperatures will cool a bit Friday with highs in the
upper 80s and low 90s. Heat indices will decrease due to the
incumbent front, added convection, and increased cloud cover across
the region.

KEY MESSAGE 2... Mostly dry conditions and lowering humidity for the
Labor Day holiday weekend ahead.

High pressure tracks southeast from the Great Lakes on Saturday,
pushing a cold front through region throughout the day. Some
uncertainty still exists regarding how far south this front will
advance south before stalling, but most ensemble members depict this
boundary south of our region by Saturday afternoon. This should
bring a drop in heat & humidity across the Mid-Atlantic, with
afternoon highs ranging in the mid-80s on Saturday. As mid-level dry
air continues to track across the area, temperatures should continue
to decrease as the weekend goes on. By the Labor Day holiday, it
should feel relatively mild & dry, with dewpoints ranging in the
upper-50s across the region.

&&

.AVIATION /01Z THURSDAY THROUGH MONDAY/...

Overall looking a prevailing VFR to MVFR conditions overnight given
a washed out boundary nearby. Winds will remain light and variable
due to the nearby front at less than 10 kts. A shower or
thunderstorms cannot be ruled out north of a line from MRB/IAD to
DCA/BWI between 06-10z/2am-6am. Went with PROB30s given the lack of
confidence in regards to coverage as convection will decaying as it
moves into the area.

Additional rounds of strong to severe thunderstorms are possible
Thursday afternoon through Friday. Expect prevailing VFR conditions
with temporary restrictions at times. Given low confidence on
timing, issued PROB30 groups for convection entering the corridor
west of MRB between 15-19z/11am-3pm before advancing east toward
IAD, DCA/BWI between 19-00z/2-8pm. Damaging winds will be the
primary threat with storms along with frequent lightning. Similar
conditions are expected Friday although timing and coverage remain
uncertain given the placement of an incumbent cold frontal boundary.

Prevailing VFR conditions are expected across all terminals for the
Labor Day holiday weekend. A few showers and thunderstorms Saturday
afternoon & evening could reduce flight categories south of KCHO.
Light northwesterly winds on Saturday shift to easterly and calm by
Sunday evening. VFR conditions look to continue into early next
week.
&&

.MARINE...
Overall looking at no marine hazards overnight although
showers and thunderstorms may sneak into the northern waters
early Thursday morning. SMWs may be needed as this activity
drops south although confidence is low. Winds will remain light
and variable otherwise at less than 10kts.

SMWS are likely again Thursday afternoon and evening as another wave
of energy pulses through. Scattered to numerous showers and
thunderstorms are possible mainly during the 3-9pm timeframe.

On Friday and Saturday, winds below 15kts most of the time, but
higher winds and waves could during afternoon and evening showers or
thunderstorms. SMWS may be needed again to encompass this threat.
Light northwesterly winds shift easterly by Saturday afternoon as
the front sags south of the waters and high pressure builds from the
north.

&&

.CLIMATE...
Record high minimums were set yesterday at IAD, DCA, and HGR.
Please RERs for detail info. More record high minimums are
possible again tonight and Thursday night.

Below is a list of record warm temperatures for September 2 and
3.

(A `+` indicates the record also occurred in previous years).

The period of record for most sites dates back to the late 1800s,
except for Sterling-Dulles Airport which dates back to 1960.

====================================================================
                            SEPTEMBER 3
====================================================================
Site                      Record Daily High   Record Daily Warm Low
Baltimore (BWI) MD           98 (2023)            79 (1993)
Washington DC                98 (1953)            79 (1993)
Sterling-Dulles Airport VA   99 (2023)            77 (1993)
Baltimore (Downtown) MD      98 (2023)            82 (1993)
Annapolis MD                 99 (1993)            79 (2018)
Hagerstown MD               100 (1953)            72 (2018+)
Martinsburg WV              102 (1953)            71 (1957)
Charlottesville VA          104 (1953)            75 (1930)

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Heat Advisory from 11 AM to 7 PM EDT Thursday for MDZ016>018.
VA...Heat Advisory from 11 AM to 7 PM EDT Thursday for VAZ029>031-
     036>040-050-051-055>057-501-502-526-527.
WV...Heat Advisory from 11 AM to 7 PM EDT Thursday for WVZ053.
MARINE...None.

&&

$$

DISCUSSION...EST/KVH
AVIATION...EST
MARINE...EST/KVH