Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

393
FXUS61 KLWX 261537 AAA
AFDLWX

Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
1137 AM EDT Sat Sep 26 2026

.WHAT HAS CHANGED...
A Coastal Flood Advisory was issued for Calvert County until 5
AM Monday.

&&

.KEY MESSAGES...
- 1) A Nor`easter brings below normal temperatures, breezy
  conditions, and some rain at times through this weekend.

- 2) Warm and calm conditions next week before rainfall chances
  return by late next week.

&&

.DISCUSSION...
KEY MESSAGE 1...A Nor`easter brings below normal temperatures,
breezy conditions, and some rain at times through this weekend.

The strong Nor`easter is located east of the Delmarva peninsula
this morning, nearly collocated with the upper level low. Dry
air/subsidence is evident on water vapor west of the low,
encompassing much of the forecast area. The northerly winds are
supplying mid 40s dew points into the area. A shortwave trough
in central Canada will cause a blocking ridge to build north of
the low tonight into Sunday, resulting in slight retrogression
to the west. The low will occlude, and shortwaves in the
northern stream will weaken the blocking ridge, allowing the
remnant low to eventually drift off to the northeast Monday.

Moisture will advect westward today, but it will likely take
some time to saturate the column, and eventually the low level
dry air will win out with westward extent. Some light rain will
move into areas along and east of I-95 this morning, likely
holding off anywhere to the west until afternoon. There`s still
some spread in the westward extent, but measurable rain becomes
much more unlikely west of the Blue Ridge.

There may be a break in the rain this evening as the low reaches
its (temporary) northern most position. After that, there is
still notable spread in where the low will track. The ECMWF and
its ensembles are clustered slightly southward, closer to Cape
May, while the GFS and Canadian ensembles allow a more northward
position, although it is worth noting some models take the low
as far north as Long Island before looping it southwestward
across New Jersey. As the pivot occurs, more rain will spread
into the area late tonight into Sunday. Chances will be highest
across the northern half of the area, and this period has the
highest chance for rain to reach as far west as the Alleghenies.
But the ultimate latitude of the low will have an impact on rain
amounts. While north central/northeast Maryland will likely see
the most rain regardless of the track, probabilities for 0.5
inch are much higher in the EC ensemble compared to the other
two ensembles.

Wind gusts will be 20-35 mph today, and up to 40 mph near the
Chesapeake Bay. Winds any higher than that are becoming less
likely. Similar or slightly lower winds are likely on Sunday,
with the highest values resulting from a farther southwest
and/or stronger low.

The warmest temperatures today (mid 70s) will be across the
Potomac Highlands and central Virginia as thicker clouds move in
from the east. On Sunday, clouds will envelop most of the area,
limiting highs to the 60s with 70s confined to central Virginia.

Coastal flooding, mostly minor in nature, will also be an
issue...see separate section below.

While rain chances and wind gusts will likely start declining by
Monday, cloud cover will likely remain stubbornly in place. The
current forecast calls for upper 60s and lower 70s, but would
not be surprised if they are a bit lower if clouds are thick.
As winds shift more northwesterly, some upslope showers or
drizzle will be possible in the Alleghenies.


KEY MESSAGE 2...Warm and calm conditions next week before
rainfall chances return by late next week.

Generally benign weather conditions for the middle to late part of
next week for our area. Upper troughing over the Northeast moves
offshore Tuesday night into Wednesday, then a fast moving Clipper
system passes by to our north Wednesday night into Thursday. Given
all of the forcing remains to the north and moisture return ahead of
the system is weak, not expecting any precip. Deep ridging develops
over the southwest Atlantic at the end of next week, which brings in
some warmer temperatures, but still not much in the way of moisture.
The next chance for rain looks to be Friday into next weekend as a
cold front approaches. Highs in the 70s for most of next week,
though low 80s are possible in the middle to late part of the
week.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
A strong Nor`easter off the coast will bring gusty north to
northwest winds today and Sunday, with perhaps a modest decrease
in gusts tonight. Gusts of 25-30 kt will be common each day,
perhaps slightly lower at MRB and CHO.

Low levels have been trending drier through tonight, so while
some light rain will likely move from east to west today, it may
not reduce visibility very much, and will likely fail to reach
MRB and CHO. MVFR ceilings may be brief at best for BWI, DCA,
and MTN. Additional rain will likely move into the area late
tonight or Sunday as the low pivots near New Jersey. There`s
still some uncertainty with the extent of this rain, with CHO
least likely to see any rain. MVFR ceilings will slowly spread
into the area as well, but this may not occur until Sunday
afternoon and evening.

Wind gusts and rain chances will decrease Sunday night into
Monday, although MVFR ceilings will likely continue through
Monday night.

VFR conditions are forecast to prevail Tuesday and Wednesday,
with no precipitation chances.

&&

.MARINE...
As the Nor`easter churns offshore of the Delmarva coast, winds
are expected to strengthen today. The Gale Warning has been
expanded to include the entire Chesapeake. While the western
waters will be farther removed from the wind fields, drier air
will promote deeper mixing, and some gale force gusts can`t be
ruled out this afternoon. This situation will be monitored.
Winds should decrease slightly tonight, with Gale Warnings
ending at 10 PM this evening.

Exactly where the Nor`easter pivots near New Jersey could impact
winds on Sunday. While Small Craft Advisories are a sure bet, a
stronger/southwestward solution could result in another period
of gale conditions.

The Nor`easter will slowly pull away Monday, although Small
Craft Advisories may be needed before winds fully subside Monday
night.

Favorable marine conditions expected through the middle of next
week. Southerly channeling is possible over the open waters of the
Chesapeake Bay on Wednesday, though still uncertain if those winds
will be near SCA strength.

&&

.TIDES/COASTAL FLOODING...

A Coastal Flood Advisory was issued for Calvert County.

Northerly winds are slowly leading to declining anomalies. It`s
possible the high tide cycle today will see no flooding, but
left the advisories for Dahlgren and Straits Point since it will
be close. As the Nor`easter lifts northward tonight and Sunday,
some guidance has water sloshing back northward. This will
extended the flood threat for the lower Potomac at a minimum,
but additional locations could also see some minor flooding.
Uncertainty continues into early next week, as some guidance has
water levels dropping as the system departs, while others keep
the levels elevated.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Gale Warning until 10 PM EDT this evening for MDZ008.
     Coastal Flood Advisory until 8 AM EDT Monday for MDZ016.
     Coastal Flood Advisory until 5 PM EDT Sunday for MDZ017.
     Coastal Flood Advisory until 5 AM EDT Monday for MDZ018.
VA...Coastal Flood Advisory until 8 AM EDT Monday for VAZ057.
WV...None.
MARINE...Gale Warning until 10 PM EDT this evening for ANZ530>534-537-
     539>543.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ535-536-538.

&&

$$

DISCUSSION...ADS/LFR/KRR
AVIATION...ADS/LFR/KRR
MARINE...ADS/LFR/KRR