ALERT For Slick-Icy Conditions Saturday Evening Into The Overnight In Locations Along And North Of The High Knob Massif-Tennessee Valley Divide In Wise, Dickenson & Buchanan Counties
A sleety mix of drizzle, frozen water droplets, and snow is coating secondary roads, cars, sidewalks etc..in Dickenson County, with showers of mostly snow appearing to be more common at highest elevations where temps are in the 10s.
*As of 6:30 PM it is now difficult to even stand up on sidewalks or exposed decks in Clintwood. CAUTION IS Advised to prevent falls!
Snow Showers & Freezing Fog – Eagle Knob of High Knob Massif – PM of December 30
As temps continue to drop more dendrites will likely develop at lower elevations, with a burst or two of heavier snow being possible as the Arctic Front crosses the western front range of the mountains Saturday night ( Dec 30 ).
*The orographic clouds producing this precipitation is being overshot by Doppler radar beams, so little is showing up.
The Coldest Air Mass Of The Season Is Expected To Arrive During New Year’s Weekend
A large mass of bitterly cold air is expected to pour south into the mountains during New Year’s Weekend. While some snow will be likely with northerly upslope flow, amounts continue to look light with a dusting up to 1″ generally being possible ( up to 2″ at upper elevations in the High Knob Massif ).
This will be the beginning of a prolonged period of bitterly cold conditions that may eventually allow for a more important winter storm to impact the Appalachians in the first week of January.
Friday Night Into Saturday Morning
Mostly cloudy. A chance of snow flurries. Winds SSW-W at 5-15 mph, with higher gusts ( especially overnight into early morning when gusts over 30 mph will become possible at highest elevations ). Temps varying from the upper 10s to upper 20s. Wind chills in the 10s to lower 20s, with single digits at highest elevations toward morning.
Saturday Morning Through The Afternoon
Mostly cloudy. A chance of snow showers & flurries. Cold. Winds W-WNW at 5-15 mph with higher gusts. Temps near steady or slowly falling in the 20s middle-lower elevations and the 10s at highest elevations. Wind chills in the 10s to lower 20s, with single digits to near 0 degrees at highest elevations ( especially in frequent gusts ). Milder south of the High Knob Massif-Tennessee Valley Divide into river valleys of the Clinch, Powell, Holston.
Saturday Night Into Sunday Morning
Turning colder. Chance of snow showers and flurries. A burst of evening snow possible, especially along and north of the High Knob Massif & Tennessee Valley Divide. Winds shifting NNW-NNE at 5-15 mph, with higher gusts. Temps dropping into the single digits to low-mid 10s. Wind chills dropping into single digits above and below zero, except to around -10 below zero in gusts at highest elevations.
Sunday Morning Through Sunday Afternoon
Mostly cloudy. Chance of flurries. Bitterly cold. N-NNE winds 5-10 mph with some higher gusts. Temperatures near steady in the single digits at upper elevations to the mid-upper 10s at lower-middle elevations along-north of the Tennessee Valley Divide and High Knob Massif. Wind chills in the single digits above and below zero.
New Year Eve Into New Year Morning
Partly to mostly clear. Bitter. N-NE winds 5-10 mph with some higher gusts along mid-upper elevation mountain ridges-exposed plateaus. Temperatures 0 to 10 degrees. Wind chills 5 above to -5 below zero below 2700 feet, with chill factors of -5 to -15 below zero at elevations above 2700 feet ( as cold as -20 degrees below zero on highest peaks ).
Due to shallow low-level moisture that is being lifted along the upslope side of the mountains, conditions have become quite icy with a nasty mix of drizzle-sleet-snow freezing on contact in the Clintwood area ( to note only one place ).
NASA Visible Image At 4:30 PM on December 30, 2017
Some vertical cloud development was showing up along the 850 MB arctic front late Saturday, with this nasty mix over the mountains falling south of this boundary.
NAM 12 KM Model 850 MB Analysis At 1 PM Saturday
The 850 MB arctic front and thermal min are important features, especially in the mountains when interacting with complex terrain. It is hoped that more snow and less drizzle will develop as the vertical temp profile turns bitter upon passage of this boundary ( which will be denoted by a shift to more northerly winds and onset of a temp plunge ).
Previous Discussion
A little snow remains on the ground around Norton-Wise, with extensive snow cover; albeit light versus normal, in the high country of the High Knob Massif.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Friday temperatures peaked at 33.8 degrees in Clintwood and around freezing or below at the elevations of Norton-Wise and Sandy Ridge ( LNP possessing a 1 degree Celsius warm bias ).
Nora 4 SSE – National Weather Service Cooperative Station – Elevation 2650 feet
It is hoped that you enjoyed this Friday’s “warmth” as temperatures are going to turn much colder during the weekend as bitter arctic air tightens its grip.
European Model 850 MB Temp Anomalies At 7 AM Friday – December 29, 2017
The source region for the incoming bitter blast could be seen this morning on the European Model analysis of 850 MB temperature anomalies across North America ( above ).
NAM 12 KM Model 850 MB Temp-Wind Forecast At 7 PM Saturday – Dec 30
While COLD will be the main story, there should be just enough moisture and lift to generate some snow showers and flurries along the upslope side of the mountains with Great Lake moisture trying to make it south following a wind shift to the north behind a passing clipper system.
NAM 3 KM Model Total Snowfall Forecast
With such bitter air it takes very little moisture to generate snowflakes, as observed most recently on December 27, when combined with low-level rising air. Snow densities will not be even close to 10:1, as models use.
Bitter cold is the main aspect of concern, with MAX temps likely to remain under 20 degrees for much of the mountain area during Sunday-Monday. Please be careful and take care of yourself, elderly and pets.
Residents who live in the high country, or those who may be planning to hunt, hike, or do other outdoor activities, should realize that temperatures during December 31-January 1 will generally remain in the single digits by day at elevations above 3000 to 3500 feet, with well below zero wind chills.
Depending upon sky cover, winds, etc…some downward adjustment of low temperatures may be necessary during the weekend-early week period.
