021616 Forecast

My Forecast For Today ( February 16 )

ALERT For Accumulating Snow Tonight – Beginning As Mix Below 2700 feet ( All Snow Above 2700 feet ) With A Fast Moving Clipper System

Steep creeks draining the High Knob Massif have had strong rises during today, so caution is advised when around these creeks. The run-off has begun to slow as air temperatures dropped back below freezing at higher elevations into the predawn-morning.

Overnight Into This Morning

Rain.  Heavy at times.  Rain changing to snow by the predawn ( especially along and west-northwest of the Cumberland Mountains ).  S-SSE winds 10-20 mph, with higher gusts, below 2700 ft.  SSE-SSW winds increasing to 15-25 mph, with higher gusts, on upper elevation mountain ridges.  Predawn winds shifting WNW-NW at 10-20 mph, with higher gusts.  Temperatures dropping during the predawn-morning back into the 20s to lower 30s.  Wind chills in the 10s and 20s along mid-upper elevation mountain ridges ( coldest at highest elevations ).

A period of moderate-heavy snow remains possible, especially in upper elevations where moderate snow has recently been falling on High Knob ( since 3:00 AM ), but trends have been for the most signficant snow band to remain just west and northwest of the Virginia-Kentucky stateline ( northwest of Pine Mountain ).

This Morning Through This Afternoon

Any early snow giving way to flurries, then mostly cloudy skies.  Winds becoming variable & light ( generally less than 10 mph ).  Temperatures varying from the upper 20s to the upper 30s ( coldest at highest elevations ).  Milder in lower elevations toward the Tri-Cities.

Tonight Into Wednesday Morning

Cloudy with snow developing.  A possible mix in lower elevations ( below 2700 feet ) at the beginning.  A period of moderate to heavy snow possible.  Winds NW-N 5-10 mph, with higher gusts, along mid-upper elevation mountain ridges.  Temperatures dropping into the 20s to lower 30s.  Wind chills in the 10s & 20s on exposed mountain ridges.

Snowfall Forecast – Tonight Into Wednesday AM

General 1″ or less north of a Cumberland to Wise Line

1″ to 2″ below 3000 feet in Norton-Wise area

2″ to 3″+ above 3000 feet in High Knob Massif

Target Snowfall of 1.2″ in Norton-Wise ( +/- ) 0.5″ .  This implies potential for 0.7″ to 1.7″ of snowfall.  In general, lesser amounts of 1″ or less will be toward Pound-Clintwood with heavier amounts to the south toward the High Knob Massif.  The centroid of the clipper is tracking to the south, with heaviest amounts likely along the TN and NC border area from the Smokies northeast.  Any south shift in the current forecast track could bring the 1″ or less line farther south into Wise County.  Although this is expected to be a light event, a period of moderate-heavy snow remains possible and sticking on roadways ( especially with freezing of any initial mixture or drizzle ) will become most likely later tonight.


Weather Discussion ( February 16 )

I have cleaned up the forecast page this afternoon for the next clipper system that races through tonight.  Snow has been falling atop the High Knob Massif since about 3 PM.

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

Orographic clouds have obscured the High Knob Massif during late afternoon, with light snow falling.  What falls will be all snow at elevations above 2500 to 3000 feet, with a center point of 2700 feet for the initial rain-snow line.  A mix will be possible below this elevation until evaporative cooling allows for mostly snow at all elevations along and north of the High Knob Massif.

*Lower elevations south of the High Knob Massif in the Clinch, Powell, and Holston river valleys may be a little slower to see transition to all snow.
High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Roads remain covered and snow depths more than 6″ in the crest zone of the High Knob Massif this afternoon, but a big snow depth decrease of up to 8″ or so occurred with 2.00″+ of total precipitation during the past 24+ hours.

Eagle Knob of High Knob Massif
Eagle Knob of High Knob Massif at 4:25 PM – Tuesday ( February 16, 2016 )
Steep creeks draining the high country began to respond by this morning, with strong rises, but also with a delay as the snowpack did act to absorb and release water more slowly.
Big Stony Creek Stream Levels
Big Stony Creek Stream Levels – Up To 8:15 AM Tuesday ( Feb 16 )