Office: LWX
FXUS61 KLWX 280145
AFDLWX
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
845 PM EST Thu Nov 27 2025
.SYNOPSIS...
Low pressure lingers over southeastern Canada while high pressure
builds across the Midwest and Tennessee Valley through Friday. High
pressure moves overhead Saturday, then pushes offshore Sunday into
early next week. Several weather systems could bring wintry
precipitation to parts of the region Sunday into early next
week.
&&
.NEAR TERM /THROUGH FRIDAY/...
Stratocumulus clouds remain more widespread east of the
mountains than most guidance has suggested. The area encompassed
does seem to be fluid, but would expect some cloud cover to
continue to spill across the divide through the night given
Froude numbers over 1. Some flurries can't be ruled out,
especially west of I-81, although substantial surface dew point
depressions and downslope subsidence will likely limit what
reaches the ground.
It is going to be even colder tonight as temps fall to the 20s, with
teens in parts of the Alleghenies. Winds remain elevated through the
night so wind chills in the teens will be widespread, and in the
single digits for the mountains. Upslope mountain snow showers
increase in coverage and intensity tonight as the main upper trough
digs into the central Appalachains. Around 2 to 4 inches of snow is
expected in western Grant and western Pendleton counties, where a
Winter Weather Advisory has been issued. Elsewhere, 1 to 2 inches
are possible along and west of the Allegheny Front. Would not be
surprised by some isolated 3 inch totals in Garrett County given
proximity to deeper moisture to the north, although this is not
reflected in most models QPF.
Cold temperatures, sufficient lift through the DGZ, and high SLRs
(currently forecast at 20:1 but given the fluffy nature of this
snow, could end up being higher) make conditions favorable for snow
to accumulate. Some limiting factors will be limited moisture due to
not directly feeding from the Great Lakes. Also, strong winds
(gusting 30-40 mph) will also limit snow totals in some areas.
Still, the 12Z HREF and most of the high res guidance point toward
several inches of snow for those favored upslope areas along and
west of the Allegheny Front tonight. The gusty winds and cold
surface temperatures may also result in difficult travel despite
the relatively light amounts.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
The main upper trough moves through the region Friday morning into
the afternoon as cold air continues to advect into our area. Highs
Friday struggle to reach the low 40s east of the Blue Ridge, and
will be in the mid to upper 30s for the I-81 corridor. The mountains
remain below freezing.
Mountain snow showers continue through Friday afternoon, then come
to an end by Friday evening. Most of the snow accumulation is
expected to finish by Friday morning, so additional snowfall will be
mostly light. However, there is going to be a period of time during
the afternoon when upper dynamics are favorable for snow squalls.
While overall coverage and location are still uncertain, any areas
that do see heavier bursts of snow will have to deal with slick
travel conditions and low visibility. This is going to be an issue
for corridors along/west of the continental divide, so thinking of
I-68, US-219, US-50, US-48, and US-33 that from Garrett, Grant, and
Pendleton counties westward. Those who intend on traveling Friday
afternoon in these areas should be mindful for rapidly changing
conditions if snow squalls move through.
High pressure builds in quickly behind the departing trough Friday
night, then the high slides overhead on Saturday. Mountain snow
showers come to an end Friday night, with dry conditions for
Saturday. The coldest temps during this stretch are most likely
Friday night with mid teens to low 20s across the area.
A cold and mostly sunny Saturday as highs reach the mid 30s to low
40s. High level clouds filter through the day as the next, potent
shortwave trough approaches from the OH Valley. Precipitation could
begin as snow or a wintry mix in the mountains late Saturday night.
However, there remains a lot of uncertainty regarding when
precipitation begins, and how quickly the wet bulb effect can eat
away at the dry air at the surface. Additionally some wintry precip
is possible in parts of the Shenandoah Valley and maybe east of the
Blue Ridge (though will have to overcome that dry air before temps
rise after sunrise). Those traveling Sunday are advised to keep an
eye on the forecast as confidence increases toward a particular
solution.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A more active weather pattern is likely to build over region late
this weekend and continue to the early parts of next week bringing
multiple chances for wintry precipitation. The first chance in the
long term period for wintry precipitation will occur Sunday into
early Monday morning as a strong sfc low passes to the north with
it's attending front moving through our region on Sunday. As
precipitation associated with the front moves into the region, cold
air in place ahead of the boundary may allow for some front end
wintry precipitation. Additional wintry precipitation will be
possible on the back end side of the front as cold air rushes into
the region. Model guidance continues to have considerable spread on
precipitation types with freezing rain and snow possible. Based
recent trends,the best chance for impactful wintry precipitation at
this time will likely be in areas along and west of the I-81
corridor.
A brief lull in precipitation is likely on Monday, but a strong
coastal low passing to the south of the region will bring another
round of precipitation to the region Tuesday into Wednesday. Weather
models have a range of solutions for the Tuesday event with some
solutions having a combination heavy rain and some wintry
precipitation and other solutions indicating the chance for a
decent accumulating snow event. National Blend of Model plume
graphics really shows the uncertainty with snow solutions ranging
from 0 inches to near 15 inches of snow. At this time, we continue
to have low confidence in the wintry threat early next week, but
it's a period of note worth keeping an eye on for planning purposes.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
VFR conditions are forecast to persist through Saturday. The main
aviation impact is going to be from strong wind gusts through
Friday. While winds may be relatively lighter tonight, some
gusts of 20-25 kt could occur at times. Winds pick up more
dramatically after sunrise, with peak gusts around 30-35 knots
expected Friday late morning to afternoon. Winds decrease
Friday evening into Friday night. Light winds expected for
Saturday.
Aviation restrictions are possible Sunday into early Monday due to a
frontal passage with another chance for restrictions towards the
middle parts of next week.
&&
.MARINE...
Hazardous marine conditions are expected to persist over the waters
through the end of this week as cold west to northwest winds
continue. Small Craft Advisories are now in effect through Friday
night for all the waters. A period of near gale force gusts will be
possible Friday morning to mid afternoon for the Chesapeake Bay
north of the Bay Bridge, and the upper tidal Potomac River. These
ares will see gusts in the lower 30 kt range. The rest of the waters
will see gusts between 25-30 knots.
Winds slowly diminish Friday night, and should fall below SCA levels
by sunrise Saturday.
Small Craft Advisories will likely be needed Sunday through early
next week with gale conditions possible.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Small Craft Advisory until 4 AM EST Saturday for MDZ008.
VA...None.
WV...Winter Weather Advisory until 9 AM EST Friday for WVZ501-505.
MARINE...Small Craft Advisory until 4 AM EST Saturday for ANZ530>543.
&&
$$
SYNOPSIS...KRR
NEAR TERM...ADS/KRR
SHORT TERM...KRR
LONG TERM...JMG
AVIATION...ADS/JMG/KRR
MARINE...ADS/JMG/KRR
