ALERT For Continuation of Dangerously Cold Conditions Through This Morning
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.
Accumulating Snow Is Likely For Wednesday With Hazardous Travel Conditions Expected. Prepare Now.
Potential Of A Major Winter Storm Is Increasing For The January 22-23 Period. Stay Tuned For Details.
Overnight Into Mid-Morning
Increasing clouds overnight into morning ( especially in upslope locations ) with a chance of flurries and light snow showers. A dusting or light accumulation in places. Bitter cold. WNW-NW winds 5-15 mph, with higher gusts along mid-upper elevation mountain ridges. Temps in the single digits above and below zero ( coldest at 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 feet.
Mid-Morning Through This Afternoon
Any flurries ending. Becoming partly to mostly sunny. WNW-N winds decreasing to generally less than 10 mph. Temperatures varying from around 10 degrees at highest elevations to upper 10s-lower 20s ( milder in snow-free valleys of the Clinch, Powell, and Holston river basins toward the Tri-Cities ). Wind chills single digits and 10s.
*Tonight Into Wednesday Morning
Increasing clouds overnight into morning. Light & variable winds becoming S-SSW by morning at less than 10 mph on mountain ridges & plateaus below 2700 ft. Winds becoming SSW-WSW at 5-15 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures varying from upper single digits to lower 10s in mountain valleys with calm winds into early overnight, rising toward dawn. Temps generally rising into 10s & 20s across exposed middle to upper elevation mountain ridges and plateaus.
*Accumulating snow is likely to develop during the day.
Weather Discussion ( January 18-19 )
Bitterly cold conditions dominated January 18 from start to finish, with MAX temperatures varying by elevation & snow cover from 17 degrees at the 1560 feet elevation of the NWS Cooperative Station in Clintwood to only 6 degrees at the summit level of the rime coated High Knob Massif.
Temperatures rising a little higher within snow-free valleys amid the Clinch, Powell, and Holston river basins where many places were able to reach into the 20s.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Wind chills were a significant factor across middle to upper elevation mountain ridges and plateaus, with 0 to -25 below values throughout the day ( coldest at highest elevations ).
Nora 4 SSE – Along The Tennessee Valley DivideEuropean Model 850 MB Temps & Surface Pattern At 7 AM Monday
Temperatures tonight have again dropped below zero along crest lines of the High Knob Massif and Black Mountain, and in a few of the high valleys amid the snow covered massif. Widespread single digit to near zero degree temps ( e.g., Norton valley ) are common in lower-middle elevations of the area at 2:00 to 3:00 AM Tuesday.
European Model 850 MB Temps & Surface Pattern At 7 PM Monday
The temperature drop is being checked a bit by low clouds which have formed on WNW upslope flow tonight into the windward slopes of the High Knob Massif and Tennessee Valley Divide. Some snowflakes are being observed on Eagle Knob of the High Knob Massif.
*Cloud bases have actually formed below the summit level of the massif where some more riming may occur amid this bitter air.
NAM Model 925 MB RH and Wind Streamline Forecast at 10:00 AM Tuesday
These developments were expected with a little bit of Great Lake moisture flowing into windward slopes through mid-morning today. This is now generating some light snow and flurries ( and narrow snowstreaks ) along the upslope side of the mountains ( with respect to WNW-NW flow ) from Clintwood & Pound into the High Knob Massif. A dusting or light accumulation will be possible in places through about mid-morning or so when low clouds will begin to dissipate.
JKL Doppler Showing Light Snow & Snowstreaks
Higher altitude clouds will begin to increase later today into tonight in advance of the next snow maker.
I will post a snowfall projection for this event in my next forecast. Preliminary indications suggest that several inches of snow may accumulate within the SW Upslope Flow corridor of the High Knob Landform ( a warm air advection type as documented many times in the past ).
