Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

914
FXUS61 KLWX 302018
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
418 PM EDT Sun Aug 30 2026

.WHAT HAS CHANGED...
A few widely scattered showers and thunderstorms will gradually
weaken through early evening, remaining mainly west of I-95.

&&

.KEY MESSAGES...
- 1) Warmer and more humid this afternoon with isolated
  thunderstorms possible.

- 2) Near-record early September heat expected.

- 3) Thunderstorm chances increase this week, but timing
     remains highly uncertain.

&&

.DISCUSSION...
KEY MESSAGE 1...Warmer and more humid this afternoon with
isolated thunderstorms.

A trough of low pressure will continue to initiate widely
scattered showers and thunderstorms, with gradually diminishing
coverage into early evening. The main threats will be spotty
brief heavy downpours and lightning strikes. A couple wind gusts
around 30 mph can`t be ruled out.

Convection should wane completely by mid to late evening leading
to a somewhat muggy but precipitation-free overnight.


KEY MESSAGE 2...Near-record early September heat expected.

A strong mid-level ridge over the southern Plains will build toward
the Mid South during the early to middle part of the week. The
latest trend is for the ridge to build further east into the TN
Valley on Tuesday and Wednesday, then break down late in the week as
a strong trough digs down from southern Canada. Having the ridge
build to the east is going to keep hot and mostly dry conditions
over the region for longer.

Despite the uncertainties, it remains likely that high temperatures
will reach the lower to middle 90s for most of the area this week.
Latest guidance indicates potential for temperatures in the upper
90s to near 100 by mid week, so long as it is not disrupted by cloud
cover or convection. Depending on smaller scale details, dew points
could end up a little higher or lower than currently progged which
will ultimately affect how high heat index values get. Values
approaching Heat Advisory criteria (100-104 west of the Blue Ridge,
105-109 east of the Blue Ridge) are possible Tuesday through
Thursday. Similar heat and humidity could persist into Friday, but
there is a lot of uncertainty for the late week temperature forecast
due to possible convective systems moving through the area.

Temperatures may begin to moderate by next weekend as a cold front
crosses the region.


KEY MESSAGE 3...Thunderstorm chances increase this week, but timing
remains highly uncertain.

Disturbances rounding a ridge to the south and west in NW flow aloft
will introduce shower and thunderstorm chances at times this week.
Given the latest trend bringing the ridge further east during the
middle of the week, that should keep most of the convective systems
over NY/PA and the Northeast Tuesday and Wednesday. That does not
mean we are completely in the clear those days; if anything, the
highest chance of seeing thunderstorms will be in northeast Maryland
during the late afternoon to evening as storms move south from PA.
By Thursday, a strong upper trough digs south from Canada which will
rapidly break down the ridge overhead. As this occurs, our area is
going to be in a much more favorable location for upstream
shortwaves to pass overhead.

The enhanced lift and shear traversing the region besieged by
several days of hot and humid conditions will introduce the
potential for some significant severe weather. AI/ML guidance has
broad elevated probabilities of severe weather much of this week,
particularly Wednesday and Thursday. It should be noted that there
is a conditional potential for one or more organized clusters of
strong to severe storms at some point this week. The most likely
time currently appears to be either Wednesday or Thursday, but
changes are likely given uncertainty at this range. It is quite
possible given latest trends that the threat is highest Thursday and
Friday as the upper ridge breaks down more readily.

Storm chances may linger into next weekend as a cold front crosses
the region on Saturday.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Widely scattered TS moving away from MRB may approach IAD and
perhaps DCA in weakening form through 23Z.

Otherwise, VFR through Thursday for the most part. Timing,
coverage, and location will be the uncertainty each day and
evening for scattered strong to perhaps severe thunderstorms.
Any storms will bring brief MVFR to IFR conditions in terms of
downpours. Winds generally south to southwest 5 to 15 knots but
very gusty in strong thunderstorms.

&&

.MARINE...
SCA remain in effect through early Monday for southerly
channeling in the large portion of the Bay. Marine Weather
Statements are in effect in inlet areas of the Bay and the
northern and central Tidal Potomac for gusty winds.

Chances of thunderstorms increase throughout the week, so
Special Marine Warnings may be needed.

&&

.TIDES/COASTAL FLOODING...
Southerly flow is increasing tide levels, and will likely result
in near minor flood stage at Annapolis this evening.

&&

.CLIMATE...
Near-record heat is possible, peaking Tuesday through Thursday.

Below is a list of record warm temperatures for September 1, 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 1
====================================================================
Site                      Record Daily High   Record Daily Warm Low
Baltimore (BWI) MD           99 (1962)            78 (1932+)
Washington DC                99 (1980+)           77 (1980)
Sterling-Dulles Airport VA   98 (1980)            73 (2000)
Baltimore (Downtown) MD      99 (1973)            80 (2012)
Annapolis MD                 95 (1962)            78 (2018+)
Hagerstown MD               101 (1902)            72 (2018+)
Martinsburg WV              103 (1932)            73 (2000+)
Charlottesville VA          105 (1932)            78 (1932)

====================================================================
                            SEPTEMBER 2
====================================================================
Site                      Record Daily High   Record Daily Warm Low
Baltimore (BWI) MD           99 (1953)            75 (1932+)
Washington DC               101 (1980)            78 (1980)
Sterling-Dulles Airport VA   99 (1980)            72 (2020+)
Baltimore (Downtown) MD      98 (1980+)           80 (1980)
Annapolis MD                 97 (1998)            79 (2018+)
Hagerstown MD               100 (1953)            73 (2018+)
Martinsburg WV              103 (1932)            72 (2000+)
Charlottesville VA          105 (1953)            80 (1930)

====================================================================
                            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...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 2 AM EDT Monday for ANZ531>534-537-
     543.

&&

$$

DISCUSSION...LFR/KLW/DHOF/KRR
AVIATION...LFR/KLW/DHOF/KRR
MARINE...LFR/KLW/DHOF/KRR
TIDES/COASTAL FLOODING...DHOF
CLIMATE...DHOF