Alert archive / Virginia / Wind Advisories in 2020

Wind Advisory 22, NWS Blacksburg, VA

December 21, 202027 counties in Virginia; 4 counties in West Virginia; 5 counties in North Carolina

NWS Blacksburg, VA issued this wind advisory at Dec 21, 2020, 5:05 AM EST for 27 counties in Virginia; 4 counties in West Virginia; 5 counties in North Carolina. It took effect at Dec 21, 2020, 6:00 PM EST. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued
Dec 21, 2020, 5:05 AM EST (10:05 UTC)
In effect from
Dec 21, 2020, 6:00 PM EST
Expired
Dec 22, 2020, 12:00 PM EST
In force
18 hr
Issued by
NWS Blacksburg, VA
All 36 counties

Alleghany County, NC, Ashe County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Alleghany County, VA, Amherst County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Carroll County, VA, City of Buena Vista, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 24 km from the middle of the area, began a volume at 10:03 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 10.1 hours before the alert went out and 86 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Roanoke, VA at 00:00Z on 2020-12-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 00:00Z on 2020-12-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1016 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

782 
WWUS71 KRNK 211005
NPWRNK

URGENT - WEATHER MESSAGE
National Weather Service Blacksburg VA
505 AM EST Mon Dec 21 2020

NCZ001-002-018-VAZ015-212000-
/O.NEW.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
Ashe-Alleghany NC-Watauga-Grayson-
Including the cities of West Jefferson, Sparta, Boone, 
Independence, Whitetop, Troutdale, and Volney
505 AM EST Mon Dec 21 2020

...WIND ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO NOON EST
TUESDAY...

* WHAT...West winds 20 to 30 mph with gusts up to 55 mph 
  expected.

* WHERE...In Virginia, Grayson County. In North Carolina, Ashe,
  Alleghany and Watauga Counties.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Gusty winds could blow around unsecured objects. Tree
  limbs could be blown down and scattered power outages could
  occur.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are
  expected overnight into Tuesday morning. Snow accumulations from
  1 inch at the lower elevations to 3 inches at the higher
  elevations can be expected. Blowing and drifting snow will be
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects. Travel should be avoid if
possible, especially where strong winds and snow accumulations are
combined.

&&

$$

VAZ007-009>014-016>018-022-WVZ042>044-212000-
/O.NEW.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-Carroll-Floyd-
Craig-Roanoke-Mercer-Summers-Monroe-
Including the cities of Tazewell, Marion, Bland, Pearisburg, 
Wytheville, Radford, Pulaski, Blacksburg, Galax, Floyd, 
New Castle, Roanoke, Salem, Bluefield, Flat Top, Hinton, Hix, 
and Union
505 AM EST Mon Dec 21 2020

...WIND ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO NOON EST
TUESDAY...

* WHAT...West winds 10 to 20 mph with gusts up to 40 mph 
  expected.

* WHERE...Portions of southwest and west central Virginia and 
  southeast West Virginia.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are
  expected overnight into Tuesday morning. Snow accumulations from
  1 inch at the lower elevations to 3 inches at the higher
  elevations can be expected. Blowing and drifting snow will be
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

RAB
4 follow-up statements
908 
WWUS71 KRNK 211915
NPWRNK

URGENT - WEATHER MESSAGE
National Weather Service Blacksburg VA
215 PM EST Mon Dec 21 2020

NCZ001-002-018-VAZ015-220315-
/O.UPG.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
/O.NEW.KRNK.HW.W.0004.201221T2300Z-201222T1700Z/
Ashe-Alleghany NC-Watauga-Grayson-
Including the cities of West Jefferson, Sparta, Boone, 
Independence, Whitetop, Troutdale, and Volney
215 PM EST Mon Dec 21 2020

...HIGH WIND WARNING IN EFFECT FROM 6 PM THIS EVENING TO NOON EST
TUESDAY...

* WHAT...West winds 20 to 30 mph with gusts up to 50 mph 
  expected.

* WHERE...In Virginia, Grayson County. In North Carolina, Ashe, 
  Alleghany NC and Watauga Counties.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Damaging winds will blow down trees and power lines.
  Widespread power outages are expected. Use extra caution when
  driving, especially if operating a high profile vehicle.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are 
  expected overnight into Tuesday morning. Snow accumulations 
  from 1 inch at the lower elevations to 3 inches at the higher 
  elevations can be expected. Blowing and drifting snow will be 
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

&&

$$

NCZ003-019-VAZ019-020-023-024-032>035-WVZ507-220315-
/O.EXA.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
Surry-Wilkes-Alleghany VA-Bath-Botetourt-Rockbridge-Patrick-
Franklin-Bedford-Amherst-Eastern Greenbrier-
Including the cities of Dobson, Wilkesboro, Clifton Forge, 
Covington, Hot Springs, Fincastle, Lexington, Buena Vista, 
Stuart, Rocky Mount, Bedford, Amherst, Lewisburg, 
White Sulphur Springs, and Alderson
215 PM EST Mon Dec 21 2020

...WIND ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO NOON EST
TUESDAY...

* WHAT...West winds 10 to 20 mph with gusts up to 40 mph 
  expected.

* WHERE...Portions of central, south central, southwest and west 
  central Virginia, north central and northwest North Carolina 
  and southeast West Virginia.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are 
  expected overnight into Tuesday morning. Snow accumulations 
  from 1 inch at the lower elevations to 3 inches at the higher 
  elevations can be expected. Blowing and drifting snow will be 
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

VAZ007-009>014-016>018-022-WVZ042>044-220315-
/O.CON.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-Carroll-Floyd-
Craig-Roanoke-Mercer-Summers-Monroe-
Including the cities of Tazewell, Marion, Bland, Pearisburg, 
Wytheville, Radford, Pulaski, Blacksburg, Galax, Floyd, 
New Castle, Roanoke, Salem, Bluefield, Flat Top, Hinton, Hix, 
and Union
215 PM EST Mon Dec 21 2020

...WIND ADVISORY REMAINS IN EFFECT FROM 6 PM THIS EVENING TO NOON
EST TUESDAY...

* WHAT...West winds 10 to 20 mph with gusts up to 40 mph 
  expected.

* WHERE...Portions of southwest and west central Virginia and 
  southeast West Virginia.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are 
  expected overnight into Tuesday morning. Snow accumulations 
  from 1 inch at the lower elevations to 3 inches at the higher 
  elevations can be expected. Blowing and drifting snow will be 
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$
872 
WWUS71 KRNK 212127
NPWRNK

URGENT - WEATHER MESSAGE
National Weather Service Blacksburg VA
427 PM EST Mon Dec 21 2020

NCZ001-002-018-VAZ015-220600-
/O.CON.KRNK.HW.W.0004.201221T2300Z-201222T1700Z/
Ashe-Alleghany NC-Watauga-Grayson-
Including the cities of West Jefferson, Sparta, Boone, 
Independence, Whitetop, Troutdale, and Volney
427 PM EST Mon Dec 21 2020

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON EST TUESDAY...

* WHAT...West winds 30 to 40 mph with gusts up to 60 mph 
  expected.

* WHERE...In Virginia, Grayson County. In North Carolina, Ashe, 
  Alleghany NC and Watauga Counties.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Use extra caution when 
  driving, especially if operating a high profile vehicle.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are
  expected overnight into Tuesday morning. Snow accumulations from
  a coating at the lower elevations to 2 inches at the higher 
  elevations can be expected. Blowing and drifting snow will be 
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

&&

$$

NCZ003-019-VAZ007-009>014-016>020-022>024-032>035-WVZ042>044-507-
220600-
/O.CON.KRNK.WI.Y.0022.201221T2300Z-201222T1700Z/
Surry-Wilkes-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-
Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-Botetourt-
Rockbridge-Patrick-Franklin-Bedford-Amherst-Mercer-Summers-Monroe-
Eastern Greenbrier-
Including the cities of Dobson, Wilkesboro, Tazewell, Marion, 
Bland, Pearisburg, Wytheville, Radford, Pulaski, Blacksburg, 
Galax, Floyd, New Castle, Clifton Forge, Covington, Hot Springs, 
Roanoke, Salem, Fincastle, Lexington, Buena Vista, Stuart, 
Rocky Mount, Bedford, Amherst, Bluefield, Flat Top, Hinton, Hix, 
Union, Lewisburg, White Sulphur Springs, and Alderson
427 PM EST Mon Dec 21 2020

...WIND ADVISORY REMAINS IN EFFECT UNTIL NOON EST TUESDAY...

* WHAT...West winds 20 to 30 mph with gusts up to 50 mph expected,
  especially on the hilltops.

* WHERE...Portions of southwest and west central Virginia and 
  southeast West Virginia.

* WHEN...From 6 PM this evening to noon EST Tuesday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

* ADDITIONAL DETAILS...In addition to the wind, snow showers are
  expected overnight into Tuesday morning. Snow accumulations from
  a coating at the lower elevations to 2 inches at the higher 
  elevations can be expected. Blowing and drifting snow will be 
  possible as well.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

MBS
457 
WWUS71 KRNK 220928
NPWRNK

URGENT - WEATHER MESSAGE
National Weather Service Blacksburg VA
428 AM EST Tue Dec 22 2020

NCZ001-002-018-VAZ015-221700-
/O.CON.KRNK.HW.W.0004.000000T0000Z-201222T1700Z/
Ashe-Alleghany NC-Watauga-Grayson-
Including the cities of West Jefferson, Sparta, Boone, 
Independence, Whitetop, Troutdale, and Volney
428 AM EST Tue Dec 22 2020

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON EST TODAY...

* WHAT...West winds 30 to 40 mph with gusts up to 60 mph 
  expected.

* WHERE...In Virginia, Grayson County. In North Carolina, Ashe, 
  Alleghany NC and Watauga Counties.

* WHEN...Until noon EST today.

* IMPACTS...Damaging winds will blow down trees and power lines. 
  Widespread power outages are expected. Use extra caution when 
  driving, especially if operating a high profile vehicle.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around
trees and branches. If possible, remain in the lower levels of
your home during the windstorm, and avoid windows. Use caution if
you must drive.

&&

$$

NCZ003-019-VAZ007-009>014-016>020-022>024-032>035-WVZ042>044-507-
221700-
/O.CON.KRNK.WI.Y.0022.000000T0000Z-201222T1700Z/
Surry-Wilkes-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-
Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-Botetourt-
Rockbridge-Patrick-Franklin-Bedford-Amherst-Mercer-Summers-Monroe-
Eastern Greenbrier-
Including the cities of Dobson, Wilkesboro, Tazewell, Marion, 
Bland, Pearisburg, Wytheville, Radford, Pulaski, Blacksburg, 
Galax, Floyd, New Castle, Clifton Forge, Covington, Hot Springs, 
Roanoke, Salem, Fincastle, Lexington, Buena Vista, Stuart, 
Rocky Mount, Bedford, Amherst, Bluefield, Flat Top, Hinton, Hix, 
Union, Lewisburg, White Sulphur Springs, and Alderson
428 AM EST Tue Dec 22 2020

...WIND ADVISORY REMAINS IN EFFECT UNTIL NOON EST TODAY...

* WHAT...West winds 20 to 30 mph with gusts up to 50 mph 
  expected, especially on the hilltops.

* WHERE...Portions of southwest and west central Virginia,
  southeast West Virginia, and the foothill in northwest North
  Carolina.

* WHEN...Until noon EST today.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$
832 
WWUS71 KRNK 221656
NPWRNK

URGENT - WEATHER MESSAGE
National Weather Service Blacksburg VA
1156 AM EST Tue Dec 22 2020

NCZ001-002-018-VAZ015-221800-
/O.EXP.KRNK.HW.W.0004.000000T0000Z-201222T1700Z/
Ashe-Alleghany NC-Watauga-Grayson-
Including the cities of West Jefferson, Sparta, Boone, 
Independence, Whitetop, Troutdale, and Volney
1156 AM EST Tue Dec 22 2020

...HIGH WIND WARNING WILL EXPIRE AT NOON EST TODAY...

Winds will remain breezy with gusts up to 35 MPH this afternoon.
Winds will continue to weaken going into this evening.

$$

NCZ003-019-VAZ007-009>014-016>020-022>024-032>035-WVZ042>044-507-
221800-
/O.EXP.KRNK.WI.Y.0022.000000T0000Z-201222T1700Z/
Surry-Wilkes-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-
Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-Botetourt-
Rockbridge-Patrick-Franklin-Bedford-Amherst-Mercer-Summers-Monroe-
Eastern Greenbrier-
Including the cities of Dobson, Wilkesboro, Tazewell, Marion, 
Bland, Pearisburg, Wytheville, Radford, Pulaski, Blacksburg, 
Galax, Floyd, New Castle, Clifton Forge, Covington, Hot Springs, 
Roanoke, Salem, Fincastle, Lexington, Buena Vista, Stuart, 
Rocky Mount, Bedford, Amherst, Bluefield, Flat Top, Hinton, Hix, 
Union, Lewisburg, White Sulphur Springs, and Alderson
1156 AM EST Tue Dec 22 2020

...WIND ADVISORY WILL EXPIRE AT NOON EST TODAY...

Winds will remain breezy with gusts up to 25 MPH this afternoon.
Winds will continue to weaken going into this evening.

$$
RCS

What forecasters said that day

The local office's own words before this wind advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this wind advisory went out at Dec 21, 4:43 AM EST, 22 minutes earlier.

Area forecast discussion, Dec 21, 4:43 AM EST, 22 minutes before
Area Forecast Discussion
National Weather Service Blacksburg VA
443 AM EST Mon Dec 21 2020

.SYNOPSIS...
A strong upper-level disturbance will move toward the region
from the northwest today and tonight bringing mountain snow and
strong gusty winds to much of the region. High pressure will
drift across the region Wednesday. By Thursday/Christmas Eve, a
very strong cold front will move into the area from the west and
then sweep across the area into Christmas Day. This front will
bring widespread rain followed by strong gusty winds, sharply
colder temperatures, and accumulating snow potentially to much
of the area, but especially the mountains.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 430 AM EST Monday...

...Strong Upper Disturbance Sweeps Through Region Tonight
Bringing Strong Winds and Mountain Snow...

A strong upper disturbance resembling an Alberta Clipper will
move rapidly southeast from the Midwest/Ohio Valley overnight
into the central Appalachians and the Mid-Atlantic by Tuesday.
This system appears much stronger than it did in the models just
a few days ago and is also tracking further south than
previously indicated. Consequently, it will bring some hazards
to the region in the form of strong and gusty winds, potentially
high wind warning criteria in the higher elevations of northwest
NC and southwest VA, with accumulating mountain snow to the
western upslope areas.

With respect to the wind hazards, a strong 850mb northwest jet
will traverse the region overnight and early Tuesday. It appears
the strongest of these winds will track across southwest VA and
northwest in particular primarily in the 06Z-12Z time frame.
During this time frame, wind speeds and gusts are likely to
reach High Wind Warning criteria at elevations above 4000 ft
such as Beech Mountain, Elk Knob, Mt. Rogers, Whitetop and
similar locations in southwest VA and northwest NC. For now,
have issued a segmented Wind Advisory for late this afternoon
through noon Tuesday for areas along and west of the Blue Ridge
primarily and south of I-64. The southwest VA/northwest NC areas
mentioned above have been segmented to account for the potential
upgrade to a High Wind Warning later today if needed.

With respect to winter precipitation, the concern for this in
western areas has ramped up considerably as well from what was
previously expected. Strong cold advection and strong orographic
orthogonal flow overnight/early Tuesday will crank up the snow
machine along the western slopes of the Alleghanys in particular
across eastern WV, but to some extent further south into
southwest VA and northwest NC. The highest elevations of western
Greenbrier could see on average from 6-8 inches with 3-6 inches
in the lower elevations of western Greenbrier county. This has
necessitated a Winter Storm Warning for these areas. Elsewhere
through the general upslope western areas, amounts will be
considerably less and mostly 1 inch or less with 2-3 inches
possible at higher upslope elevations such as Beech Mountain
and Mt. Rogers, but not enough area covered to warrant an
advisory at this point. However, the threat for snow
accumulation and blowing snow will be mentioned in the HWO.

Temperatures today will rebound nicely with southwest flow in
advance of the Alberta Clipper and have leaned toward the warmer
side of guidance, especially across the Piedmont. Yesterday was
evidence of how with southwest flow and sunshine temperatures
can rebound nicely, especially with no snow/ice left across most
of the CWA. High today should range from the 40s in the west to
the 50s in the east. Lows tonight will be mainly in the 20s west
and 30s east.

/Confidence Levels in Forecast Parameters/
Temperatures - Moderate,
Precipitation Probabilities - Moderate,
Winds - Moderate to High,
Snow Accumulations - Moderate.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
As of 145 AM EST Monday...

Look for windy conditions on Tuesday, a dry but cloud day on
Wednesday, and a potent cold front for Thursday.

Tuesday morning, we expect that the winds that ramped up Monday
night will continue into Tuesday morning. However, they are expected
to quickly decrease in speed once we reach the early afternoon. At
this point in time, model 850mb winds are forecast to start to back
and decrease to 20 to 30 kts, as compared to the forecast 40 to
50kts as late as 1000 AM EST. While the winds are very gusty from
the northwest, look for a continuation of upslope snow showers
across parts of western Greenbrier County, WV. However, these too,
will be on fast decrease from the late morning into the early
afternoon.

Tuesday night, a quick moving upper ridge is forecast to head east
across the area, and then be positioned by daybreak Wednesday.
Nearly stacked with the upper ridge, will be surface high which will
take a similar path and timing. This will allow for winds to trend
towards calm or near calm through the night, and perhaps pick up a
bit of southerly trajectory by daybreak in the west.

On Wendesday, an upper low is expected to head eastward from the
Dakotas into the western Great Lakes region. Its associated upper
trough and surface cold front will extend south coincident to the
Mississippi River Valley by sunset. In advance of this feature,
south to southwest winds will be increasing across our region, and
start advecting Gulf of Mexico moisture poleward. While we are not
expecting precipitation yet on Wednesday, cloud cover will be on the
increase such that all locations will be mostly cloudy to cloudy by
sunset.

Precipitation will start to arrive Wednesday evening in the west in
the form of patchy light rain, and spread east and increase in
coverage as the night progresses within a region of isentropic lift
in advance of the cold front. Winds could be gusty again, but
perhaps not as gusty as winds expected Monday night into Tuesday. We
may need to watch the far southeastern sections of the region for
potential downsloping gusts as the southerly 850mb jet increases.
For now, we will offer gusts of 25 to 30 mph in this region
Wednesday night.

On Thursday, the deterministic models are showing variation in
timing on the passage of the cold front Thursday. This in turn
impacts parameters such as surface temperature/dew point, wind
direction/shift timing, and p-type as colder does, or does not,
advect into the region by the afternoon. Our forecast will reflect
the output offered by the national blend of models, which is in
similar alignment of features as the 00Z Canadian solution. This
solution places a generous coverage of rain across the area Thursday
morning with a cold frontal passage early to mid-afternoon. By the
late afternoon, precipitation will trend showery, with enough cold
air racing in behind the front to allow for change to or mix with
snow for mainly the highest elevation of the mountains.

Thursday night, we are expecting northwest flow to prevail across
the area with upslope snow showers for the typical spots of
southeast West Virginia, south into the Northern Mountains of North
Carolina. However, before the northwest flow strengthens in the
east, precipitation along the backside of the front and arriving
colder air may allow for isolated to scattered rain/snow showers to
reach even far eastern sections of the area.

Temperatures during this portion of the forecast will average five
to ten degrees above normal for Tuesday and Thursday, but near
normal on Wednesday.

Confidence in the above portion of the forecast is moderate. With a
lot of elements to potentially have impact on the area, especially
wind on Tuesday, and some snow and wind Thursday into Thursday
night, attention will need to be given to forecast trends of these
elements with today's forecast a snapshot of what could be.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 PM EST SUNDAY...

Santa delivers the coldest air so far this season on Christmas
Day.

A big change to the weather pattern as we head into the holiday
thanks to a strong cold front and trough entering the region. Models
continue to show uncertainty here in regards to timing,
precipitation type, and intensity of the cold airmass that looks to
pull in. The GFS continues to remain too fast with the front/incoming
cold airmass speeding east Christmas Eve morning and afternoon. The
Euro and Canadian along with ensemble guidance continues to trend
slower with a front that enters the region Thursday morning and
slowly passes through late Christmas Eve night. These two models are
also slower and a bit warmer when it comes to the incoming arctic
airmass. Unfortunately the odds of a White Christmas especially east
of the Blue Ridge still remain low with the predominant p-type
leaning toward rain instead of snow.

Even though uncertainty remains with the timing/intensity of the
front, we do know that colder conditions are on the horizon. Once
the front passes gusty northwesterly flow will take over driving
temperatures well below average on both Friday and Saturday. Most of
the area Christmas Day may struggle to reach freezing. A few
leftover snow showers over the mountains Saturday morning will give
way to high pressure and a warming trend heading into the weekend
ahead. Our next storm system looks to arrive early next week.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
As of 100 AM EST Monday...

...Poor Aviation Conditions in Fog and Low Clouds This
Morning...improving mostly to MVFR Conditions by Afternoon...

Widespread low clouds and fog developing across much of the CWA
early this morning as a result of the wet ground from
yesterday's light precipitation, calm winds, and clearing of the
mid/high clouds above. There is really no good push of westerly
flow until after daybreak. Thus, the concern is increasing for
the need of a Dense Fog Advisory. As a result have led toward
rather pessimistic TAFs through 12Z/13Z with visibilities
dropping into the IFR-LIFR range and ceilings as well through
this time frame. After daybreak, westerly flow will increase as
the upstream northwest flow trough approaches. This should allow
the ceilings to improve into the MVFR range in the west and VFR
range in the east. Nonetheless, moisture is reluctant to leave
the area and the upstream approaching trough will result in
upslope cloud cover increasing west of the Blue Ridge by
evening. Net result is a continued cloudy day but with some
improvement in aviation categories.

Winds overnight will generally be light and variable. However,
expecting to see winds increase by Monday afternoon as another
system approaches from the west. Will begin to see gusty winds
out of the west, especially along and west of the Blue Ridge.
Will once again see deteriorating conditions for BLF/LWB as
rain/snow showers begin to enter the area around 6-8PM Monday
along with lowering ceilings.

/Confidence Levels in Forecast Parameters/
Moderate Confidence in Ceilings and Visibilities,
Moderate to High Confidence in Wind Direction and Speed

Extended Aviation Discussion...

Sub-VFR conditions are likely at times across the entire area,
but especially the western mountains into Tuesday and Wednesday
with a rather unsettled pattern in place.

A strong cold front will arrive Christmas Eve accompanied by
sharply colder temperatures and very strong gusty winds into
Christmas Day. Snow showers with accumulating snow of at least a
few inches likely in the western mountains, including KBLF and
KLWB. MVFR or better conditions should return to areas east of
the Blue Ridge.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Wind Advisory from 6 PM this evening to noon EST Tuesday for
     VAZ007-009>018-022.
NC...Wind Advisory from 6 PM this evening to noon EST Tuesday for
     NCZ001-002-018.
WV...Wind Advisory from 6 PM this evening to noon EST Tuesday for
     WVZ042>044.
     Winter Storm Warning from 5 PM this afternoon to noon EST
     Tuesday for WVZ508.

&&

SYNOPSIS...RAB
NEAR TERM...RAB
SHORT TERM...DS
LONG TERM...DS/ET
AVIATION...RAB
Hazardous weather outlook, Dec 20, 10:17 PM EST, 6 hours 48 minutes before
Hazardous Weather Outlook
National Weather Service Blacksburg VA
1017 PM EST Sun Dec 20 2020

WVZ508-211000-
Western Greenbrier-
1017 PM EST Sun Dec 20 2020

This Hazardous Weather Outlook is for southeast West Virginia.

.DAY ONE...Tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Light to moderate snow accumulations are likely Monday night and
Tuesday along with strong gusty winds.

Very gusty winds and low wind chills are possible Friday night and
Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ001-002-018-VAZ007-009>020-022>024-WVZ042>044-507-211000-
Ashe-Alleghany NC-Watauga-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-
Montgomery-Grayson-Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-
Botetourt-Rockbridge-Mercer-Summers-Monroe-Eastern Greenbrier-
1017 PM EST Sun Dec 20 2020

This Hazardous Weather Outlook is for northwest North Carolina,
southwest Virginia, west central Virginia and southeast West
Virginia.

.DAY ONE...Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Strong, gusty winds are likely Monday night and Tuesday.

Very gusty winds and low wind chills are possible Friday night and
Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ004>006-020-VAZ043>047-058-059-211000-
Stokes-Rockingham-Caswell-Yadkin-Henry-Pittsylvania-Campbell-
Appomattox-Buckingham-Halifax-Charlotte-
1017 PM EST Sun Dec 20 2020

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia and south central
Virginia.

.DAY ONE...Tonight.

Patchy dense fog may reduce visibility below one mile at times.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Very gusty winds and low wind chills are possible Friday night and
Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ003-019-VAZ032>035-211000-
Surry-Wilkes-Patrick-Franklin-Bedford-Amherst-
1017 PM EST Sun Dec 20 2020

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia, south central Virginia,
southwest Virginia and west central Virginia.

.DAY ONE...Tonight.

Patchy dense fog may reduce visibility below one mile at times.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Strong, gusty winds are likely Monday night and Tuesday.

Very gusty winds and low wind chills are possible Friday night and
Saturday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Special weather statement, Dec 21, 12:02 AM EST, 5 hours 3 minutes before
Special Weather Statement
National Weather Service Blacksburg VA
1202 AM EST Mon Dec 21 2020

NCZ003>006-019-020-VAZ016-032-043-210900-
Surry-Stokes-Rockingham-Caswell-Wilkes-Yadkin-Carroll-Patrick-
Henry-
Including the cities of Dobson, Danbury, Eden, Yanceyville,
Wilkesboro, Yadkinville, Galax, Stuart, and Martinsville
1202 AM EST Mon Dec 21 2020

...Areas of Dense Fog Overnight...

The combination of light winds and moist ground from Sunday
morning's light rain has resulted in the development of areas of
fog late Sunday night which will continue overnight and into the
early morning hours Monday. Visibilities have dropped to less than
one mile at Wilkesboro, Mt. Airy, and around Reidsville. Areas of
dense fog were also forming along Interstate 77 between the NC/VA
state line and Exit 8, near Fancy Gap VA.

If you are planning travel through the North Carolina Foothills,
Piedmont, Southside Virginia, and especially the Interstate 77
corridor south of Hillsville toward North Carolina, use extreme
caution in travel this morning. Reduce speed, allow extra distance
between you and the vehicle in front of you, use low beam
headlights, and be prepared for rapid variations in visibility
from one location to another. On Interstate 77, heed all warning
signs posted by the Virginia Department of Highways and State
Police regarding speed limits.

If the fog becomes worse and more widespread, a Dense Fog Advisory
may be needed later tonight.

RAB

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 21, 2:15 PM ESTHigh Wind WarningRNKGrayson22 hr
Dec 21, 4:56 AM ESTWinter Storm WarningRNKGreenbrier31 hr

Nearby

Wind Advisories in Virginia, 2020Wind Advisories in North Carolina, 2020Wind Advisories in West Virginia, 2020Every wind advisory in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.