Arlington, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

545
FXUS61 KLWX 121929
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
229 PM EST Thu Nov 12 2026

.WHAT HAS CHANGED...
Mountain snow forecast continues to trend downward over the
Alleghenies for tonight through Saturday. Most thunderstorm
activity has now transitioned north of the region, with
intermittent showers continuing into tonight.

&&

.KEY MESSAGES...
- 1) First snowfall for parts of the Alleghenies with spotty showers
& brisk conditions elsewhere through Saturday.


- 2) Cooler temperatures and dry conditions expected through mid
  week.

&&

.DISCUSSION...
KEY MESSAGE 1... First snowfall for parts of the Alleghenies with
spotty showers & brisk conditions elsewhere through Saturday.

Overall not too much of a change from the morning forecast package
outside of decreasing PoPs and filtered breaks of sunshine east of
the mountains. Still monitoring the progression of low pressure
ejecting east out of the southwest PA this afternoon. The low is
currently located in the vicinity of of Altoona/Latrobe, PA over the
Laurel Highlands and will continue to trek east toward the southern
NJ/Delmarva coast late tonight into Friday. At the surface, is a
lead shortwave trough which produced a brief round of severe weather
in Cecil Co. MD earlier this afternoon and the potential for
tornadoes over Delaware Valley/NJ heading into the early evening
period given increased convergence. Northeast MD is now out of the
severe weather risk this afternoon although a few more showers
cannot be ruled out along the MD/PA/DE border through this evening
as the low and it`s associated front work east. Most areas east of
the mountains continue to see downsloping flow which in turn has
shredded PoPS and led to filtered breaks in cloud cover. Mountain
locations are also mostly dry with pockets of showers and drizzle
mainly from Bayard, WV points south given the fetch behind the low
pressure system off of Lake Erie and Lake Michigan. As the low
pushes east and northwesterly flow increase expect the coverage of
showers eventually changing to snow showers over the Alleghenies to
increase heading into Friday and Friday night.

00, 06, and 12z guidance has backed off quite a bit in regards to
snow amounts with the bulk of the accumulations stretched over a 24
to 30 hour period. Marginal temperatures at onset will also impact
accumulations with most of the snow falling Friday morning into
Friday afternoon. Guidance has come into better agreement in lagging
snow shower chances over the mountains through at least Saturday
before things begin to shutdown as high pressure builds back into
the region. Friday night into Saturday looks to be the most
impactful snow at least when it comes to untreated surfaces given
temperatures below freezing and snow ratios on the order of 12:1
increasing to 14-16:1 at times. These will of course be maximized at
elevations above 2000 feet and in particularly the upslope favored
zones of western Garrett, western Pendleton, and western Grant
counties. If travel disruptions were to materializes, expect impacts
to US-219 from the MD/PA line to WV line, US-48 from Mount Storm, WV
west to Davis, WV, and US-33 west of Franklin, WV. Snow
accumulations will remain on the order of a coating to 2" with
the greater probabilities of 1-2" with localized 3" amounts
above 3000 feet pending any squalls/streamers (mainly late
Friday night through Saturday midday).

Temperatures will begin to drop tonight as this frontal passage
moves through, continuing to get chillier into the weekend as winds
gust up to 25 knots Friday-Sunday. Additional rain showers are
likely primarily north & east of the I-70 corridor throughout the
day Friday. Most rain east of the Blue Ridge likely diminishes by
Friday evening, with temperatures becoming noticeably colder between
Friday and Sunday. Overnight lows range in the upper 20s to mid 30s
areawide through the weekend, with daytime temperatures generally in
the 40s to low 50s & remaining near freezing across the
mountains.

KEY MESSAGE 2...Cooler temperatures and dry condtions expected into
the middle of next week.

Upper level troughing remains over the east coast through early next
week with upper level ridging pivoting overhead by midweek. At the
surface, high pressure builds in from the west yielding dry
conditions. Conditions dry out areawide on Sunday as winds weaken in
the afternoon and upslope snow becomes less likely. As high pressure
builds overhead, light winds can be expected through next week along
with dry conditions areawide. As far as temperatures, below normal
temperatures continue early in the week with high temperatures
ranging from the 30s in the Alleghenies to the mid 50s in the metros
on Sunday. As high pressure settles overhead, temperatures moderate
with highs in the 50s and 60s by Wednesday. Overnight low
temperatures drop into the 20s to low 30s for most with only those
in the metros staying in the mid 30s. The growing season ends this
weekend so frost/freeze headlines will not be issued.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Predominantly VFR conditions are expected across the area through
the 00z TAF period outside of terminals west of KCBE and KSHD.
Overall aviation conditions will improve with scattered to broken
ceilings this afternoon and evening ahead of the low pressure system
ejecting out of southwest PA. An isolated to scattered shower
remains possible at terminals north of a line from KOKV to KDCA. Any
shower activity will be light between now-23z/2-6pm as the front
pushes through.

Upslope showers will continue over the mountains tonight before
changing to snow showers Friday into Saturday. Expect a brief period
low cigs and vsbys prior to daybreak for all terminals outside of
CHO with improvements Friday afternoon and evening as drier air
pushes into the region. Sub-VFR conditions will remain over the
mountains through Saturday as upslope snow showers continue.

Expect west to southwest winds this afternoon to shift to the
north and northwest this evening. Gusts will increase to around
20 kts overnight with 20-30 kt gusts out the northwest for
Friday and Saturday as cold air advection funnels in. BKN- OVC
stratocumulus deck is expected Fri-Sun during the day, with
additional showers possible primarily at KBWI & KMTN during the
day Friday as the cold front/low pressure push further offshore.

Northwest winds on Sunday blow around 10 knots with gusts between 15
and 20 knots expected. Winds diminish overnight with light northwest
winds expected on Monday. Surface high pressure building overhead
yields VFR conditions both days.

&&

.MARINE...
Small Craft Advisories go into effect for all waters at 6pm
tonight and continue through Friday. Winds strengthen this
evening in the wake of a strong cold front, with frequent gusts
up to 20 knots expected. Winds strengthen further Friday into
Saturday with gusts up to 30 kts possible. Winds may diminish
some on Sunday, but gusts up to 20 knots remain possible.

Small Craft Advisories are likely to continue into Sunday as gusty
northwest winds continue. Winds diminish overnight into Monday and
are expected to drop below SCA criteria.

&&

.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory has been issued for Annapolis (Anne
Arundel County) between 2100-0300 UTC this evening, as strong
northwesterly flow likely brings water levels to minor flood
stage. Several other coastal sites are likely to see Action
stage this evening correlating with high tide as winds shift
northwest behind a strong cold front. A prolonged period of
blowout tides is possible starting Friday through early next
week as winds stay elevated behind the front.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory from 6 PM this evening to 6 PM EST Friday
     for MDZ008.
     Coastal Flood Advisory until 10 PM EST this evening for MDZ014.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EST Friday
     for ANZ530>543.

&&

$$

DISCUSSION...AVS/EST/SRT
AVIATION...AVS/SRT
MARINE...AVS/SRT