011816 Forecast

My Forecast For Today ( January 18 )

ALERT For Dangerously Cold Conditions Monday & Tuesday With Bitter Temperatures and Wind Chills Amid The Coldest Air Mass Since Last February

Once Air Temperatures Drop Below 20 degrees In Norton-Wise tonight, they may not rise above 20 degrees ( for any length of time ) until Wednesday.  They will certainly not rise above 20 degrees for those living on northern slopes.  Snow cover of 1-3″, or more in spots, will make conditions colder within locations having snow on the ground.

***Remember to dress warmly and to plan not to be outdoors longer than necessary.  Check on our elderly residents, take measures to protect pets ( e.g., horses, dogs, cats etc…need shelter from the cold & wind as well as ice free water ).  

Temperatures at the High Knob Lookout will drop below zero tonight, rise only into single digits Monday and go below zero again into Tuesday Morning.  Wind Chills will be EXTREME.  Travel & visitation to there is not recommended.

High country lakes will freeze over during this event, as will many ponds & slow running creeks.  Caution Is Advised as ice may not become thick enough to walk across safely.

Ice Thickness Guidelines From MN DNR 


Overnight Into This Morning

Turning bitterly cold.  Scattered snow showers & flurries diminishing overnight into the predawn.  Temperatures plunging to -4 to 8 above zero into the overnight-morning hours ( somewhat “milder” in valleys leeward of the High Knob Massif and Cumberland range ).  Wind chills varying from 5 above to -10 below zero across mid elevation ridges & plateaus, with -10 to -25 degree below zero wind chills in upper elevations above 3000 feet.

*Note that the air will become so bitter than any passing cloud can still generate flurries today; although, I will call for mostly sunny skies after any morning clouds evaporate amid drying air.

This Afternoon

Mostly sunny & bitter.  WNW winds 5-15 mph, with higher gusts ( especially at higher elevations ).  Temperatures in the single digits and teens ( topping 20 degrees officially only in “milder” snow-free valleys amid river basins of the Clinch, Powell, and Holston ).  Bitter wind chill factors of from 0 to 12 degrees at elevations below 2700 feet, and from 0 to -15 below zero across upper elevations.

Tonight Into Tuesday Morning

Mostly clear in the evening with some increasing clouds overnight into morning ( especially in upslope locales ).  Bitter cold.  WNW-NW winds 5-15 mph, with higher gusts along mid-upper elevation mountain ridges.  Temperatures in the single digits above and below zero ( coldest at the highest elevations ).  Wind chills 0 to -15 below zero along middle elevation ridges and plateaus below 2700 feet, with chill factors of -10 to -25 below zero on ridges above 2700 ft.

Two important systems are being watched for wintry potential this coming week.  The weaker first system is currently timed to arrive Wednesday ( January 20 ).

A second, potentially Major Winter Storm system, is currently timed to impact the region during the period from Thursday into Saturday ( January 21-23 ).

A third system, in a series, of potential concern may develop during the January 25-27 period.

Stay tuned for updates.


Weather Discussion ( January 17-18 )

Afternoon Update – A BITTER ONE

Although sunshine finally returned to rule the afternoon it has been a bitter one.  Let’s check out a few RAW statistics!

High Knob Massif Webcam
High Knob Massif Webcam – University of Virginia’s College At Wise

PM MAXS as of 3:30 PM included:

Clintwood 1 W: 17 degrees
Elevation 1560 feet

City of Norton WP: 14 degrees
Elevation 2342 feet

Nora 4 SSE on Long Ridge: 12 degrees
Elevation 2650 feet

Black Mountain MesoNET: 7 degrees
Elevation 4031 feet

Joe Carter of the City of Norton Water Plant reported the daytime MAX of 14 degrees at 3:30 PM.  At the same time, some 1800+ vertical feet above the city the temperature was 5 degrees on High Knob ( wind chill of -12 below ).

Nora 4 SSE - Site of Official NWS Station
Nora 4 SSE – Site of Official National Weather Service Station


All of a sudden, or so it seems, a very active Janaury weather pattern has developed.  Two different systems impacted the mountain region just during January 17.

European 16 KM Model 850 MB & Surface Pattern
ECMWF Model 850 MB & Surface Pattern At 7 AM on January 17, 2016
The morning initialization by the ECMWF Model was rather impressive looking, with a well developed cyclone that was responsible for killer tornadoes in Florida.
This storm system being just outside of the snowstorm “strike zone” ( as in baseball ) for the southern Appalachians.  Almost in need of instant replay, but not quite ( it was close and a wanna-be snowstorm for certain ).

The first was a far southward tracking southern system that only brushed the southern Appalachians.  A general 0.5″, or a bit more, of snow accumulation was measured from the City of Norton Water Plant into Wise, Pound, and Clintwood during a period of morning snowfall supported by weak northerly upslope flow and some divergence aloft.

Snowfall came in on the low end of my forecast range for the Great Valley of eastern Tennessee and the Blue Ridge province across western North Carolina into southern Virginia, with generally a dusting to 1″ being reported.
High Knob Massif Webcam
High Knob Massif Webcam – University of Virginia’s College At Wise

The High Knob Massif was majestically rime coated but only partially visible at times, especially late in the afternoon, as cloud bases lifted in advance of a approaching Arctic Front.

High Knob Massif Webcam
High Knob Massif Webcam – University of Virginia’s College At Wise

This front was the real deal, as I expected, with whiteout conditions developing from Pound & Clintwood into Wise and the City of Norton to Appalachia during the 9:30 PM to 10:00 PM period.  This was a wind driven and vigorous line of snow squalls featuring graupel snow at times, as well as large dendrites.  Widespread snow accumulations of 1″ or more occurred ( a low density, fluffy snow in general ) to bring the official NWS snowfall total to 2.2″ in Clintwood for this day ( at an elevation of 1560 feet ).

Widespread and hazardous road conditions developed along the entire U.S. 23 corridor from Pound Gap to Little Stone Mountain Gap, as well as along adjoining roads such as Route 83.
Some drifting occurred in the High Knob Massif where sub-zero wind chill factors accompanied the heavy snow to create truly wicked conditions.
Reference my 011716 Forecast page for more details.
ECMWF Model 850 MB
ECMWF Model 850 MB & Surface Pattern At 7 PM on January 17, 2016

Focus now shifts to a huge mass of true, arctic air that will engulf the mountain region in bitter air through today and Tuesday.  The coldest air mass since February 2015.

Although the entire region will be bitter, I expect snow covered locations to be colder during the Monday-Tuesday period as snow helps to chill this low-level air even more with northern slope sites being especially bitter.

 Several systems are lined up to impact the mountain region during the next 7 days, so stay tuned for updates on this active mid-late January pattern.

Stay safe on this MLK Monday.