859
FXUS61 KRNK 291458
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
958 AM EST Sat Nov 29 2025

.SYNOPSIS...
High pressure will pass overhead today on its way to push off
the Atlantic coast tonight. This will be followed closely by
areas of mixed wintry precipitation across the mountains and
possibly the foothills early Sunday as a cold front approaches
from the west. High pressure passes across the region on
Monday. Low pressure moving across the Southeast will bring the
next chance for a wintry mix during Monday night and Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 955 AM EST Saturday...

Key Messages:

1) Warmer this afternoon under mostly sunny skies and light
winds.

2) Chance of wintry precipitation  across the mountains and
foothills late tonight.

Very little change needed to the ongoing forecast. Due to
mostly sunny skies, after a cold start in the teens and lower
20s, temperatures should rebound into the upper 30s to lower 40s
in the mountains, and mid to upper 40s in the Piedmont, before
high clouds increase from the west late this afternoon.

Previous discussion...

Update: A Winter Weather Advisory has been issued from 2 am to
noon on Sunday for the mountains and foothills for the potential
of areas of freezing rain. Details below.


As high pressure overhead moves east today, expect warmer
afternoon temperatures, particularly across the mountains, as
winds shift more from the southeast. Highs today will be 5 to 12
degrees warmer over those occurring Friday along and west of
the Blue Ridge, and will reach into the mid 30s to the mid 40s
areawide. Clouds will increase in coverage beginning shortly
after sunset, but it won`t be enough to keep temperatures from
falling quickly below freezing early in the night given the dry
air situated across the lower Mid-Atlantic.

Moisture will begin to cross the central Appalachians after
midnight Sunday morning as a cold front approaches from the
west. With temperatures below freezing as the moisture arrives,
there is strong consensus in the latest weather data that
precipitation will likely start as a brief period of snow,
before transitioning to a mixture of sleet and freezing rain
along and west of the Blue Ridge before dawn. As the moisture
continues to move in, temperatures will gradually warm from
west to east, and precipitation will change over to rain for
most locations after sunrise. That stated, there will be zones
along the higher ridges that linger in a layer of subfreezing
temperatures into early afternoon, where freezing rain may
persist longer.

As precipitation will remain light during the morning hours of
Sunday, icing accumulations from freezing rain are expected to
remain below 0.10 of an inch. However, given the very chilly
air that`s been present since Wednesday night, there is a
chance that ice will adhere to roadway surfaces, particularly
along bridges, overpasses and elevated roadways along and west
of the Blue Ridge. This will result in an increased probability
of hazardous travel conditions for Sunday morning until
temperatures warm up enough to allow the icing to melt.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
As of 115 AM EST Saturday...

Key Points:

1) Light wintry mix expected northern sections Sunday morning.

2) Dry Monday.

3) Potential for more robust wintry mix Monday night through
Tuesday.

4) Temperatures slightly below normal for this time of year.

A look a the 28 Nov 00Z NCEP Ensemble Mean 500mb Geopotential
Heights for Sunday/Sunday night depict a deep closed low
centered just north of Hudson Bay. Its associated trough axis is
expected to extend south into the Lower Ohio Valley around
evening time. Across western CONUS, a shortwave trough is
expected from WY southwest into Baja California. An amplified
ridge will be positioned just offshore the Pacific Northwest.
For Monday/Monday night, the trough which was over the Ohio
Valley on Sunday progresses northeast and is expected to be
centered over the Canadian Maritimes by Monday evening. Looking
west, the trough which was over western CONUS shifts east into
central CONUS, and merges with yet another shortwave trough in
association with the closed Canadian low. Southwest flow is
expected over our region. For Tuesday/Tuesday night, the central
CONUS trough shifts east, reaching the Great Lakes to Gulf
Coast States region by the early evening.

At the surface for Sunday/Sunday night, low pressure will
progress through the Ohio Valley early Sunday morning, and reach
southern Quebec by the evening hours. Its associated warm
front, followed by its cold front, will cross our region during
the course of the day. High pressure will be building south
through the Upper and Mid Mississippi Valley. For Monday/Monday
night, the Mississippi Valley high will progress east, and
become centered over PA/NY around early Monday evening. An
inverted trough is expected to develop across the Lower
Mississippi Valley into the western Tennessee Valley by this
same time. For Tuesday/Tuesday night, the inverted trough
deepens into low pressure which is expected to head northeast
and be off the mid-Atlantic coast by the early evening hours.
High pressure becomes centered over the mid-Mississippi Valley.

A look at the 28 Nov 12Z NAEFS Ensemble Situational Awareness
data shows 850mb temperatures for Sunday has temperatures
mildest in the morning, ranging from around 0C to +3C, north to
south across the area. By the evening, values range from -5C to
+2C, along a nw-se gradient with a cold front crossing the
region. For Sunday night, temperatures trend cooler by a couple
of degrees before increasing and reaching a range of -2C to +2C,
n-s by the early evening on Monday. For Tuesday, values start
the day around 0C to +5C, nw-se. By the early evening, the nw-se
gradient tightens to roughly -2C to +4C.

The above weather patterns offers the following forecast.
Precipitation ongoing at the start of Sunday is expected to be
primarily rain for the southern two-thirds of the region as
warm air advection continues south of an advancing warm front.
However, northern sections of the region will still have pockets
of sub-freezing surface conditions, or a warm nose not quite
warm enough for full melting to yield areas of freezing rain
and/or sleet. The trend in the potential for light snow looks
less likely, but not zero as timing of the warm air advection
could be still be too quick. By the late afternoon, the cold
front arrives along with northwest flow cold air advection. This
process will remove any lingering warm nose features and allow
for purely a snow versus rain scenario across the area. Best
chances of light snow remain over southeast West Virginia and
neighboring counties of southwest Virginia. The precipitation
will exit the region from west to east late Sunday afternoon
into early Sunday evening.

High pressure visits the region briefly on Monday for a dry and
slightly cooler than normal day.

Our next, and potentially more potent wintry weather maker is
currently on track for a late Monday night into Tuesday
timeframe. An upper trough moving east through the central
CONUS is expected to help usher a surface trough/low northeast
from the Gulf Coast towards and across our region -- all while
receiving support from the larger synoptic scale trough.
Moisture and warm air advection will enter the region starting
Monday night. This moisture will encounter a boundary layer
airmass with a mix of readings both above and below freezing. As
the night progresses, these boundary layer values will trend
slowly higher, some exceeding 32 degrees, others not. This
paints the picture of a potential wide mix of precipitation
types for the region Monday night, with the best chance of a
cold rain across southeastern portions of the area, and the best
chances for snow in the far northwest and north. In between
these two extremes, a mixture of snow, freezing rain, and/or
sleet are probable.

For Tuesday, the scenario may be similar to that which is
expected on Sunday, just with higher qpf values. The warm air
advection will continue such that a greater expanse of the
southern half of the region changes to a pure cold rain with the
north maintaining a wintry mix, but with less of a chance for
snow. By the afternoon, after the passage of the main upper
trough axis, we switch to cold air advection northwest flow.
This would place us within a pattern conducive to a rain vs snow
forecast, with the best snow potential over western and
northern parts of the region. Precipitation is expected to
conclude Tuesday evening.

Temperatures during this portion of the forecast are expected
to average few degrees below normal.

Confidence in the above weather scenario moderate on the the
timing of synoptic features and the precipitation types on
Sunday. Confidence is low regarding precipitation types, timing
and amounts Monday night into Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
As of 130 AM EST Saturday...

Key Points:

1) Dry Wednesday and possibly Thursday for most of the region.

2) Low confidence in light rain/snow for the area on Friday.

3) Temperatures trending milder through the period.

A look at the 28 Nov 00Z NCEP Ensemble Mean 500mb Geopotential
Heights shows for Wednesday/Wednesday night, the trough centered
to our west on Tuesday progresses quickly to over southeast
Canada by Wednesday evening. A broad longwave trough oriented
ne-sw is expected over western CONUS. Another shortwave trough
heads southeast on the western side of the stalled deep cut-off
low near Hudson Bay. For Thursday/Thursday night, a shortwave
trough heads through the Great Lakes region. A broad longwave
trough over western CONUS become elongated eastward. A ridge
axis moves onshore the Pacific Northwest. For Friday, the
ensemble solution offers a solution of a very broad longwave
trough covering much of central and western CONUS oriented ne-sw
associated with stalled low pressure near Hudson Bay.

At the surface for Wednesday/Wednesday night, the center of
high pressure moves over the Tennessee Valley. A weak cold
front will be over the western Great Lakes region. For
Thursday/Thursday night, a ridge of high pressure remains over
our area, but the center of the high shifts to over the mid-
Mississippi Valley. For Friday, a ridge axis remains over the
region, but its center is lost to ensemble averaging.

A look at the 28 Nov 12Z NAEFS Ensemble Situational Awareness
data shows 850mb temperatures for Wednesday of 0C to +2C, north
to south across the area. For Thursday, values trend
significantly colder to -5C to 0C, nw-se. On Friday, values
inch higher slightly to -2C to +1C.

The above weather patterns offers the following forecast. While
the ensemble mean solution places a west-east oriented ridge of
high pressure over our region Wednesday through Friday, it is
not a clear cut period of dry weather for the area. Within the
ensemble, the day with the highest probability of being dry is
Wednesday. For Thursday, some solutions have a northern stream
system getting close enough to the region for some light
precipitation for northwest parts of the area. For Friday, both
a northern and a southern stream system potentially flirt with
offering our region with some precipitation. Temperatures are
expected to trend milder through the period.

Confidence in the above weather scenario is low to moderate.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
As of 630 AM EST Saturday...

VFR conditions will persist through the 30/12Z TAF period. Just
some high clouds today, but with increasing and lowering clouds
thereafter. Ceilings may approach MVFR at BLF/LWB by 12z Sunday
with light rain/snow. Winds stay light and turn more southeast
later today. A few gusts to 20kts possible tonight at BLF.


.EXTENDED AVIATION OUTLOOK...

A wintry mix with sub-VFR is expected Sunday morning mainly
along/west of a ROA-BCB line. Icing will be an issue for those
terminals. Should see it change to rain between 14z-17z.

Expect MVFR, possibly IFR from ROA west Monday, with VFR east.
Most sites except possibly BLF return to VFR Monday evening,
with VFR for all Monday morning. Another system arrives with
more wintry weather Monday night so expect sub-VFR cigs/vsbys
late Monday night into Tuesday. Return to VFR for most by
Wednesday, slower at BLF.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Winter Weather Advisory from 2 AM to noon EST Sunday for
     VAZ007-009>020-022>024-032>035.
NC...Winter Weather Advisory from 2 AM to noon EST Sunday for
     NCZ001-002-018.
WV...Winter Weather Advisory from 2 AM to noon EST Sunday for
     WVZ042>044-507-508.

&&

$$

SYNOPSIS...NF/WP
NEAR TERM...NF/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...NF/WP