Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

157
FXUS61 KLWX 120129
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
929 PM EDT Fri Sep 11 2026

.WHAT HAS CHANGED...
Hourly trends have been touched up, but there are no major
changes to the forecast at this time.

&&

.KEY MESSAGES...
- 1) A few showers possible overnight, then likely widespread
  convection Saturday into Saturday night.

- 2) Dry conditions expected early next week ahead of a midweek
  cold front.

&&

.DISCUSSION...
KEY MESSAGE 1...A few showers possible overnight, then likely
widespread convection Saturday into Saturday night.

The slow moving frontal boundary has now pushed into North
Carolina. A few showers are drifting eastward across central
Virginia, generally in a weakening state. The bulk of the
overnight hours, and possibly through midday Saturday, may be
dry in most locations. However, by the second half of tonight,
850 mb winds become southerly, and overrunning moisture could
produce a few light showers or some drizzle. Guidance also
indicates potential for fog overnight. While some radiation fog
could form over northwestern parts of the area where it is still
mostly clear, it appears the main driver of reduced visibility
will be lowering stratus, particularly close to the ridges. Most
locations will have overnight lows in the 60s.

Surface high pressure over southern New England slides offshore
Saturday causing southeasterly flow to develop/strengthen over the
Mid-Atlantic. The synoptic pattern gets messy into the weekend as an
elongated trough stretches from the Deep South to Mid-Atlantic. The
stalled boundary over southern VA lifts north as a warm front
Saturday morning, bringing a possibly first round of showers to the
area. As the boundary lifts north of the MD/PA border, warm sector
showers are possible at time Saturday afternoon, though the bulk of
convection is set to arrive toward the evening hours.

Numerous embedded shortwaves lift across the Tennessee Valley toward
the southern Mid-Atlantic, helping produce ample lift and shear
across the region. A surge of tropical moisture brings PWATs to
around 2" Saturday afternoon into Saturday night. A wave of surface
low pressure may try to develop somewhere in lee of the Alleghenies
Saturday evening as the strongest shortwave traverses the region. A
subtle jet streak develops ahead of the upper trough, and while not
overly impressive it will be enough to aid in widespread showers and
thunderstorm development. Locally heavy rain is likely in some
areas, though the 12Z high res guidance does not point to any one
specific location. Later analysis on areas of low-level convergence
that set up will be key to determine where a flash flood threat
could develop. But for now, have not issued any Flood Watches due to
uncertainty in location of heaviest rain. WPC has expanded the
Slight Risk area for excessive rainfall to include the Alleghenies
where soils are more saturated from rain over the past month. Will
continue to monitor the situation as new mesoscale guidance arrives.

A cold front associated with the upper trough finally swings through
the area Sunday morning to afternoon, bringing an end to any
lingering showers. This front won`t bring much of an airmass change
as temps still reach the 80s and humidity lingers.

KEY MESSAGE 2...Dry conditions expected early next week ahead
of a midweek cold front.

Upper-level ridging begins to build over the Southeast beginning
Monday and into Tuesday as the cold front transitions offshore.
Humidity & temperatures decrease in the wake of the cold front on
Monday, with dewpoints ranging in the 50s and low 60s as mid-level
dry air transitions overhead. Monday night might be the first
fall night of widespread lows in the 50s.

Overall, anticipate seasonal, dry conditions to persist over the
following days as this ridging continues to build into the midweek
period. Beginning Wednesday, this ridging begins to transition into
more of a zonal flow overhead as a trough further north forms over
Quebec and Nova Scotia. An associated cold front could begin to
track across the East Coast sometime during this period, although
current guidance shows some spread in the timing of this frontal
passage. This front could bring some showers and thunderstorms to
the region, but probability of severe weather remains low at this
time.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
A front that is moving south of the area this evening is going
to stall tonight, then lift north as a warm front Saturday.
Expect sub-VFR conditions to overspread the area from south to
north Saturday morning. There is uncertainty as to how far north
the sub-VFR CIGs are. Currently DCA is near the cutoff, with
lower probabilities at BWI/MTN. CHO has the highest chance of
IFR. These ceilings may lift by Saturday afternoon, but timing
is very uncertain. For the second half of tonight through
Saturday morning, only a few showers or some drizzle are
possible. More widespread showers and scattered thunderstorms
are expected areawide Saturday afternoon into late Saturday
evening. The latest guidance suggests afternoon coverage may
mostly remain south/east of the terminals, with a more
widespread area of rain lifting north Saturday evening while
combining with decaying convection moving eastward from the Ohio
Valley. Rain may be heavy at times, although confidence was not
quite high enough yet to mention thunderstorms in the metro
areas, where instability may be a bit weaker. Coincident with
rain arriving, ceilings will also drop back to MVFR and likely
to IFR. Rain should taper off the second half of Saturday night,
but the ceilings may not lift until midday Sunday.

A couple of reinforcing cold fronts move through the region Sunday
into Sunday night, with VFR conditions returning in WNW/NW winds.

Prevailing VFR conditions are anticipated across terminals Monday
through Wednesday. A few lingering showers could temporarily bring
reduced conditions near KCHO on Monday, but otherwise conditions
remain mostly clear throughout Tuesday & Wednesday. Northerly winds
shift southeasterly by Tuesday night.

&&

.MARINE...
A front is stalling south of the waters tonight, then will lift
north as a warm front Saturday night. An increase in southeast
winds over the waters Saturday could be near SCA levels. Late
afternoon to late evening thunderstorms could lead to hazardous
marine conditions, with Special Marine Warnings possibly needed.
A secondary front moves through Sunday, then a stronger cold
front on Monday. Wind gusts could increase to near marginal SCA
thresholds on Monday before diminishing throughout the day
Tuesday. Winds stay below SCA criteria through Wednesday.
Northeasterly winds shift southeasterly in the wake of a cold
front by Tuesday night.

&&

.TIDES/COASTAL FLOODING...
Strengthening onshore flow Saturday will bring tide levels up across
the area. Some locations could reach Action Stage by Saturday night
to early Sunday high tides. A cold front moves through Sunday, and
again Monday, which should bring an end to any coastal flooding
potential.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...ADS/KRR/SRT
AVIATION...ADS/KRR/SRT
MARINE...ADS/KRR/SRT