Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

764
FXUS61 KLWX 211815
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
215 PM EDT Tue Apr 21 2026

.WHAT HAS CHANGED...
Slightly breezier conditions have developed this afternoon with
gusts of 15 to 25 mph a bit more widespread, highest over the
higher elevations. Otherwise, there haven`t been any significant
changes to the forecast over the next several days.

&&

.KEY MESSAGES...
- 1) Warming temperatures mid to late week as a cold front
  drops into the area and stalls.

- 2) Cooler air moves in this weekend, along with chances for
  showers.

&&

.DISCUSSION...
KEY MESSAGE 1...Warming temperatures mid to late week as a cold
front drops into the area and stalls.

As Canadian high pressure slides off toward the south, a quick-
moving cold front will drop into the region Wednesday. There
will not be a whole lot of moisture to work with, so any
rainfall amounts are likely to be meager in nature (less than a
0.10"), and mainly focused near and north of I-66/US-50. Some
instability in the atmosphere could produce a few thunderstorms,
particularly during the afternoon hours Wednesday. A lack of
stronger forcing, shear, or instability should lead to generally
weak convection, though some spotty downpours, gusty winds, and
small hail can`t be ruled out.

After a chilly start to the work week, ensembles agree on a
warm up through the middle to latter portions of the week. High
temperatures could push back into the low/mid 80s by Friday
ahead of another system likely to bring a return of rain by the
second half of Friday.

KEY MESSAGE 2...Cooler air moves in this weekend, along with
chances for showers.

A complex upper-level pattern will unfold across the region
this weekend as upper ridging in place breaks down while two
large upper lows (one over the Northern Rockies, one over the
Northern Atlantic) start to interact. High pressure will
strengthen off to our northeast, which will force a backdoor cold
front to push further southwestward into our forecast area.
Meanwhile, a decaying disturbance associated with the western
upper low will track overhead. Showers appear likely this
weekend as a result, with the greatest chances occurring on
Saturday as the aforementioned upper disturbance moves through.

There`s still some uncertainty with respect to the ultimate
positioning of the front, and as a result, there`s still a wide
range of potential temperatures. Locations on the warm side of
the boundary may approach 70, while locations on the cool side
will likely be stuck in the 40s and 50s. Chances for cooler
conditions will be greater off to the north and east, while
chances for warmer temperatures will increase toward the
southwest. Chances for showers decrease further on Monday, with
temperatures expected to fall near seasonable levels (highs in
the upper 60s to low 70s).

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR conditions continue through Friday. Some temporary sub-VFR
conditions are possible with a weak cold front Wednesday. The
front could bring brief -SHRA/-TSRA at the terminals Wednesday
morning into Wednesday afternoon. Handled the most likely times
(initial frontal push, then diurnal pop ups) with PROB30s. Areas
down around KCHO may see nothing at all. Winds remain south
tonight at less than 15 kts with southwest winds ahead of the
front Wednesday switching back to the northwest Wednesday
afternoon. Gusts Wednesday will remain between 15 to 20 kts at
the TAF sites. Some LLWS also possible overnight tonight as
S/SW flow increases aloft ahead of the boundary.

Additional WAA showers are possible by Friday afternoon which
could be accompanied by a few restrictions. Winds will be out
of the NW on Thursday.

VFR conditions and light east to northeasterly winds are
expected on Friday. Sub-VFR ceilings appear likely on Saturday,
along with easterly winds and showers.

&&

.MARINE...
SCAs have been extended/expanded tonight into Wednesday morning
with moderate southerly channeling expected. Sub-SCA level
winds are expected Wednesday afternoon through Friday with
winds out of the SW to NW as a cold front crosses and stalls.
This front may bring a few showers and thunderstorms mainly
Wednesday afternoon.

Sub-SCA level NW to E/NE winds are expected over the waters
Thursday/Friday. SCA-level gusts appear possible in easterly
flow on Saturday.

&&

.FIRE WEATHER...
RH will recover to 55 to 75 percent tonight, and will likely
continue rising across the Alleghenies Wednesday while holding
steady elsewhere. RH may drop in around 40 percent south of I-64
Wednesday afternoon. Winds will likely gust 20 to 30 mph as they
shift to out of the west along and west of I-81 and near and south
of I-64 Wednesday afternoon. Given the downsloping flow, RH could
drop more than forecast in the I-64 corridor (to near 30 percent)
resulting in a locally elevated fire weather threat in those
areas. Light rain amounts are expected (generally 0.10" or less)
near and north of I-66/US-50 Wednesday, with additional rain
potential Friday into the weekend.

&&

.TIDES/COASTAL FLOODING...
Southerly flow is expected to strengthen tonight. This will
result in rising tidal anomalies. The higher members of P-ETSS
and SFAS, as well as STOFS and CBOFS all hint at the potential
for minor flooding at Annapolis early Wednesday as a result.
Have sided with this side of the guidance envelope given a
favorable channeling setup.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 6 PM this evening to 8 AM EDT
     Wednesday for ANZ530-535-536-538.
     Small Craft Advisory from 6 PM this evening to noon EDT
     Wednesday for ANZ531>534-537-539>543.

&&

$$

DISCUSSION...KLW/DHOF/KJP
AVIATION...KLW/DHOF/KJP/EST
MARINE...KLW/DHOF/KJP/EST