Ashburn, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

995
FXUS61 KLWX 230026
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
726 PM EST Mon Dec 22 2025

.SYNOPSIS...
Low pressure tracking over the Great Lakes may bring light wintry
precipitation chances to portions of the area late tonight into
Tuesday morning. Conditions look to dry out east of the mountains
Tuesday afternoon with high pressure briefly building overhead
Wednesday. A warm front will slowly approach from the southwest
Thursday bring a few passing showers. An area of low pressure will
traverse the boundary as it stalls nearby or just to the south
Friday bringing the potential of a wintry mix. A stronger cold front
arrives toward the end of the weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
Special Weather Statements have been issued for eastern Garrett,
western Allegany, western Grant, western Mineral, western
Highland, and western Pendleton counties for light freezing
rain/sleet. Any accumulations will be minor given the ample dry
air leftover at the surface and main forcing with the system
remaining north of the area into PA. Even with that said, a
light glaze of ice is possible on elevated/untreated surfaces
across the colder pockets of the Allegheny Mountains, crest of
the Blue Ridge, and Catoctins. Any freezing/rain/sleet in these
locations will quickly change to rain after sunrise Tuesday
morning as temps warm into the mid to upper 30s.

Surface high pressure will continue offshore tonight leading to
increasing clouds and mid-level moisture. Some echoes have been
noted west of the Blue Ridge and into the Alleghenies this evening
with some light snow flurries/virga back across
Somerset/Bedford counties in PA. These echoes are in association
with high pressure shifting offshore and the resultant warm
front/low pressure system pushing into the region from the Great
Lakes/Ohio River Valley. As the front approaches from the south
and west, moisture advection will increase, especially during
the second half of the night into daybreak Tuesday. This will
lead to increasing precipitation chances over the mountains and
in locations along and north of I- 66/US-50. Further south the
precipitation chances drop off given the residual dry air
leftover at the surface from departing high pressure just
offshore.

With increasing cloud cover expect lows to hold in the low to mid
30s. The colder pockets of the Alleghenies and northeast MD(where
clear skies hang on the longest) could see lows in the upper 20s.
These locations stand the greatest probability of seeing a wintry
mix (snow/sleet/freezing rain to rain) compared to locations further
south where a brief wintry mix (snow/sleet) is possible before a
transition over to rain. Temperatures remain marginal throughout the
event with ground temperatures in the 30s and 40s limiting impacts
to elevated and untreated surfaces. Locations south of I-66/US-50
may not see anything at all given the dry air in the low and mid
levels.

Any snow accumulations will be light and attributed to wet
bubbling especially along the PA/MD line where a dusting of snow
is possible. Ice accumulations will also remain light with a
glaze of elevated and untreated surfaces (i.e cold air drainage
areas of the Alleghenies, Catoctins, and crest of the Blue
Ridge).

Rain moves out of the area by Tuesday afternoon with lingering rain
showers in the Alleghenies through the evening.
Temperatures will be 5 to 15 degrees warmer with highs in the mid
40s to low 60s across the area. The main weather story will be gusty
winds as the cold front pushes across the area. Higher elevations
along the Allegheny Front may approach wind advisory criteria, but
lower elevation winds will not be as strong.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Rain moves out of the area by Tuesday afternoon with lingering
rain showers in the Alleghenies through the evening.
Temperatures will be 5 to 15 degrees warmer with highs in the
mid 40s to low 60s across the area. The main weather story will
be gusty winds as the cold front pushes across the area. Higher
elevations along the Allegheny Front may approach wind advisory
criteria, but lower elevation winds will not be as strong.
Behind the front, overnight lows will be in the 30s across the
area.

High pressure builds over the area on Wednesday with dry
conditions expected. Similar to Tuesday, there will be a large
spread in high temperatures with the Alleghenies and NE
Maryland staying in the 40s and central VA nearing 60 degrees.
Overnight and into Thursday, a warm front approaches from the
west with precipitation chances increasing from west to east
overnight. Overnight low temperatures will be in the 30s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The long term period will start off on Thursday with deep troughing
along the West Coast, broad longwave ridging centered over the
middle of the CONUS, and then troughing again just to the east of the
Atlantic coastline. This will place us in northwesterly flow aloft.
A weak disturbance will descend down in northwesterly flow from the
Great Lakes during the day Thursday. There`s still some disagreement
in guidance with respect to the track of this system, with some
guidance tracking the system overhead, while others keep it
suppressed off to our south and west. Depending on which solution
verifies, we could either have some showers throughout the day, or
mostly cloudy and dry conditions. Temperatures are forecast to range
from the mid 40s across northeast Maryland to near 60 in Central
Virginia.

Meanwhile, another disturbance will emerge out of the West Coast
trough and rapidly track up over the central US ridge Thursday into
Thursday night, before diving east-southeastward toward the Mid-
Atlantic on Friday. Guidance has shifted significantly southward
with the track of this system with each of the last few model runs.
As a result, many solutions now show wintry precipitation across the
northern half of the forecast area (roughly I-66/US-50 northward).
Of the solutions that do have wintry precipitation, most favor
freezing rain and sleet, but some snow can`t be completely ruled out
depending on the ultimate track of the system. The upstream flow
pattern across the North Pacific (from which this system will
originate) is highly complex at the moment, with critical pieces
that will come together still to the west of the California coast,
in the Gulf of Alaska, and in the Bering Strait. Another closed
upper low to the west of Hawaii will likely also have a major impact
on how the West Coast trough evolves. As a result, there could still
be significant shifts with respect to the track of this system over
the next few model runs, and confidence in the forecast is much
lower than normal for five days out.

The aforementioned system will progress off to our east by Saturday,
leading to drier conditions locally. A much deeper closed upper
level low is expected to approach from the northwest on Sunday,
potentially leading to the next chance for rain. A very strong
Arctic front will likely move through later Sunday into Sunday night
as the system departs. Windy and much colder conditions are expected
by Sunday night, with precipitation potentially ending as a little
upslope snow in the mountains.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A warm front will approach from the south and west late tonight
into Tuesday morning bringing light precipitation chances to
the terminals. A light wintry mix is possible at all terminals
outside of KCHO Tuesday morning (between 6-11z/1-6am) as the
leading edge of precipitation moves through. The wintry mix will
be short lived with a transition to rain after sunrise Tuesday
morning. Currently have PROB30s for -RASN, although
restrictions are not expected until after the precipitation has
moved out Tuesday morning where MVFR ceilings are possible.

Drier conditions return east of the mountains late Tuesday morning
into Tuesday afternoon as the front lifts north and a weak cold
front pushes through the area. The cold front will lead to a wind
shift from the south back to the northwest with gusts of 15 to 25
kts. VFR conditions are expected Wednesday as brief high pressure
builds back over the region.  Winds remain out of the northwest,
gusting 15-20 knots in the morning before diminishing in the
afternoon. Light winds are expected at KCHO all day.

Sub-VFR conditions may be possible at times on both Thursday and
Friday as disturbances track toward the area from the Great Lakes.
Some showers may be possible on Thursday, and a wintry mix of
precipitation appears possible during the day Friday. Winds look
relatively light, and direction is a bit uncertain at the moment,
and will depend on the ultimate track that the systems take.

&&

.MARINE...
A Small Craft Advisory remains in effect for the the open waters of
the lower tidal Potomac and middle/lower Chesapeake Bay through
Tuesday morning. South winds of 10 to 15 kts are expected with gusts
up to 20 kts at times. Winds diminish below SCA levels Tuesday night
before turning to the west and northwest Tuesday night into
Wednesday. Additional SCA advisories may be needed Wednesday as
winds briefly gusts 15 to 20 kts in the morning due to southerly
channeling. Sub-SCA level winds appear likely on both Thursday and
Friday.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 1 AM to noon EST Tuesday for ANZ531-
     532-539-540.
     Small Craft Advisory from 1 AM to 3 PM EST Tuesday for ANZ533-
     534-537-541-543.

&&

$$

SYNOPSIS...EST
NEAR TERM...AVS/EST
SHORT TERM...AVS
LONG TERM...KJP
AVIATION...AVS/KJP/EST
MARINE...AVS/KJP/EST