ALERT For Periods Of Snow Friday Into Saturday Morning With Widespread Hazardous Travel
ALERT For Bitterly Cold Conditions Friday Into Sunday
Overnight Into Friday Morning
Light snow & flurries. Winds WNW-NNW at 5-15 mph, with higher gusts. Temperatures dropping into 10s to around 20 degrees ( as cold as 10 degrees at highest elevations ). Wind chills in the single digits and 10s, except below zero in gusts along upper elevation mountain ridges. Rime formation in upper elevations.
Friday Afternoon
Periods of snow and flurries. Bitterly cold. Winds NW to N at 5-10 mph. Temps varying from lower-mid 10s in upper elevations to lower-middle 20s. Wind chill factors in single digits & 10s ( coldest at highest elevations ).
Updated Snowfall Forecast: Friday Into Saturday
A general 1″ to 4″ of new snowfall is expected, with locally heavier totals in upper elevations of the High Knob Massif. My target has been changed to the expected snow depth in the Norton-Wise area by Saturday, and has only been adjusted to account for new snowfall.
Target Snow Depth 5″ In Norton-Wise ( +/- ) 1″ Error Potential. This suggests a possible range from 4″ to 6″ in Norton-Wise by Saturday ( this includes snow that fell through Thursday ). Deeper depths will be possible in the High Knob Massif ( above 2700 feet ).
New snowfall Friday into Saturday will tend to be less toward the north, in places that received the most snow through Thursday, and greater toward the south from Norton-Wise into the High Knob Massif and adjacent Great Valley region.
Friday Night Into Saturday Morning
Periods of snow & snow showers. Heavy at times. Bitterly cold. NNW-N winds 5-15 mph, with higher gusts on middle to upper elevation mountain ridges. Temperatures varying from 0 to 12 degrees. Wind chills from 5 above to -10 below, except -10 to -20 degrees below zero upper elevation ridges.
Saturday Afternoon
Snow showers and flurries ending. Partial clearing possible by late PM. Bitterly cold. NW winds 5-15 mph, with higher gusts. Temperatures varying from single digits within the upper elevations to 10s across lower-middle elevations. Wind chills in the single digits above and below zero.
Saturday Night Into Sunday Morning
Mostly clear. Bitter. NW winds 5-15 mph along upper elevation mountain ridges. Diminishing winds in valleys. Temperatures varying from 5 above to -5 degrees below zero, except locally colder in mountain valleys.
Weather Discussion ( Harsh Weather )
Friday Afternoon Update
My only change is to ease the expected snow depth up a little from Norton-Wise southeast across the High Knob Massif as snowfall tonight becomes moderate to heavy before tapering to upslope snow showers & flurries.
I already had the coldest forecast of any sources, and if anything it may be even colder than I have predicted.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Around 2″ of snow is now on the ground across the Norton-Wise area, with 2-3″ in upper elevations of the High Knob Massif where significant rime has transformed the landscape into a winter wonderland amid bitter air.
A total of 2.1″ of snow was reported by Caleb Ramsey at the City of Norton Water Plant ( 2″ on the ground ) around 5:00 PM.
A total of 2.0″ has been measured in Clintwood, with locally more across northern Dickenson County ( mainly from Thursday ).
Upper Elevations At 4031 Feet
This air mass along the western side of the mountain chain is bitterly cold, with 4:30 to 5:00 PM temperatures varying from 10 degrees on Eagle Knob of the High Knob Massif and 11 degrees ( 10.6 ) on Black Mountain to 16 degrees on Sandy Ridge and 17 to 19 degrees in Norton-Wise.
Middle Elevations At 2650 Feet
Air will turned even colder into Saturday as temperatures plung toward 0 degrees at the top of the high country and to single digits to around 10 degrees at elevations of Norton-Wise and Sandy Ridge ( low-mid 10s at lower elevations ).
Temperatures during the day Saturday will remain in single digits at upper elevations and the 10s in Norton-Wise and in most of the Cumberland Mountains ( wind chills will make conditions feel even colder ).
HRRR Model Total Snowfall Forecast Next 15-Hours
The focus now turns to a final round of snow that is likely to become heaviest from the High Knob Massif area south and southeast. This should push ground depths into my forecast range for Norton-Wise, and could exceed them if upslope on northerly flow becomes more of a factor with low density snowfall than models are currently indicating.
New snow accumulations tonight are likely up to along the VA-KY stateline, as past climatology of these events dictate, with a rapid diminishing of snowfall northwest of Pine Mountain and a notable gradient across the High Knob Massif area as upsloping N winds increase into the overnight and Saturday morning ( increasing amounts across the high country toward Norton-Wise ).
Travel tonight into Saturday is discouraged as bitterly cold air & snow will combine to generate widespread hazardous travel conditions.
Air is turning bitter with more periods of snow upcoming into Saturday. Places that received the most snow during Thursday, with 1-2″ in Clintwood and as much as 2″ to 5″ from John Flannagan Lake & Breaks Interstate Park into portions of Pike County, Ky., will tend to get the least.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Locations toward the south will get the most snow through Friday Night into Saturday, from Norton-Wise and the high country of the High Knob Massif southeast toward the TN-NC border and Great Valley ( where very little to no snow accumulated through Thursday Night ).
NAM 4 KM Model Total Snowfall Forecast To 7:00 AM Saturday – January 7, 2017
The track and moisture supply will be critical, with any shift northwest producing more snowfall across the entire area while a shift toward the southeast will restrict new snow to mainly locations toward the TN-NC border and Great Valley. The Mountain Empire is on the fence.
*A composite of all models, including Ensembles, plus past climatology of systems embedded within this type of upper air setting suggests that accumulating snow with the main system will reach up to the Virginia-Kentucky border, then taper rapidly toward the northwest and north. Amounts will increase toward the southeast of the VA-KY stateline, with the High Knob Massif being a local focus via upsloping northerly flow and very cold air to produce low density snowfall.
Black Mountain Mesonet
Bitter cold is the other main story, with temperatures at just before 5:00 AM Friday varying from 12 degrees atop Eagle Knob of the High Knob Massif to 22 degrees in Clintwood ( a little milder SE toward the Great Valley ).
*Freezing drizzle has been reported into the Great Valley.
