Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

255
FXUS61 KLWX 220127
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
927 PM EDT Sun Jun 21 2026

.WHAT HAS CHANGED...
No major changes were made to the forecast this evening.

&&

.KEY MESSAGES...
- 1) Strong to severe thunderstorms along with locally heavy
 rainfall possible on Monday.

- 2) After a mid week dry spell, daily thunderstorm
 chances will return for the end of the week.

&&

.DISCUSSION...
KEY MESSAGE 1...Strong to severe thunderstorms along with
locally heavy rainfall possible on Monday.

A low pressure system is forecast to track from the Ohio River
Valley northeastward across Pennsylvania on Monday with the
associated warm front lifting north across the region throughout
the day. This will bring the next chance of severe weather to
the region, with the Storm Prediction Center having most of the
forecast area in a Slight Risk for severe thunderstorms.
Guidance is coming into better agreement that an initial round
of storms will form along a pre- frontal trough during the early
afternoon hours and then move across the forecast area from
west to east. This round of storms should press off to the east
of the area by the early evening hours. Some guidance shows
additional storms developing behind this initial activity, while
other solutions show little redevelopment after the initial
round. If the second round of storms were to occur, they would
likely move through during the evening to early overnight hours,
with most storms winding down by around 1 AM or so.

With southerly flow, a warm and moist airmass is expected
leading to adequate instability. Additionally, winds will
increase aloft, leading to 30-50 knots of effective bulk shear.
The combination of instability and shear leads to a risk of
organized storms, some of which could be supercells. Damaging
wind gusts appear to be the primary threat, but a brief tornado
can`t be completely ruled out.

While storm motion is expected to be progressive, PWATS nearing
and/or exceeding 2 inches will lead to locally heavy rainfall within
the strongest storms. In addition, some models are showing the
potential for two rounds of thunderstorms in the afternoon and
evening. The Weather Prediction Center has most of the area in a
Slight Risk for excessive rainfall with scattered instances of
flooding possible.


KEY MESSAGE 2...After a mid week dry spell, daily thunderstorm
chances will return for the end of the week.

There is still some uncertainty where the cold front will be Tuesday
and whether there are any linger showers or perhaps a thunderstorm
as the mid level trough axis moves through. These chances are
slightly higher for the southern half of the CWA, but many locations
could remain dry. Temperatures will dip back slightly below seasonal
averages into the upper 70s to mid 80s.

High pressure will move across the area Wednesday, resulting in the
most pleasant day of the week. Temperatures will be near or
slightly below normal with relatively low dew points in the 50s
and mostly sunny skies.

A slow moving upper level trough/closed low and broad surface low
pressure will slowly lift through the Great Lakes Thursday and
Friday. While temperatures may not rise appreciably, there will
be a return to muggier dew points. Specific forcing may be
nebulous on Thursday especially, but locations west of the Blue
Ridge will have greater instability and be closer to the upper
trough, so these locations may have the highest chance of
thunderstorms. The thunderstorm threat will encompass the entire
area Friday as the surface cold front drops closer to the area.
Some shear will be present, but instability may be limited, so
the severe weather threat is uncertain at this time (supported
by low ML guidance probs).

Forecast uncertainty increases for next weekend as the frontal zone
will behave like a typical weak summer front that may not entirely
clear the area and only have minimal airmass differences across it.
Saturday could be relatively drier as high pressure moves into the
Great Lakes. However, the stalled front and potential for
ripples in the quasi-zonal flow aloft could bring a chance of
showers and thunderstorms each day in a warm and humid airmass.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR conditions are expected through the overnight as dry
conditions continue. Showers and thunderstorms are expected
Monday afternoon and evening with flight restrictions likely.
Outside of storms, southerly winds could gust to 25 kt.

There may be some lingering showers Tuesday depending on how quickly
the cold front moves through. Northwest winds may gust to 20 kt
Tuesday. Wednesday will likely be dry. Thunderstorms are possible
again on Thursday (especially CHO and MRB) and Friday
(areawide).

&&

.MARINE...
Light winds are expected through the overnight. Winds shift to
southerly on Monday with a Small Craft Advisory in effect from
9AM to 6PM. Additionally, showers and thunderstorms are
expected across the waters Monday afternoon and evening with
SMWs likely needed.

Northwest winds behind a cold front may result in marginal advisory
conditions on Tuesday. Light winds are expected Wednesday under high
pressure. Small Craft Advisories may be needed Thursday afternoon
into Thursday night in southerly flow. The next upper level
disturbance could bring more thunderstorms Thursday and Friday
afternoon and evening.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from noon to 6 PM EDT Monday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from noon to 6 PM EDT Monday for ANZ530-
     535>538-542.
     Small Craft Advisory from 9 AM to 6 PM EDT Monday for
     ANZ531>534-539>541-543.

&&

$$

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