Low clouds. Dense fog widespread at upper elevations into the overnight hours, then lifting bases possible by morning. Locally dense fog at middle to lower elevations. Scattered showers with local thunder & small hail possible ( drier to the west & southwest of Pennington Gap ). Light & variable winds. Temperatures dropping into the 40s to lower 50s.
Friday Afternoon
Cloud bases lifting. Becoming mostly to partly cloudy. Seasonally cool. W-SW winds 5-10 mph, with higher gusts, especially on mid-upper elevation ridges-plateaus. Temps varying from the mid-upper 50s in the upper elevations to the mid-upper 60s.
Friday Night Into Saturday Morning
Partly-mostly clear. Chilly. SSW-SW winds 5-10 mph, with higher gusts, along mid-upper elevation mountain ridges. Temperatures varying from the upper 30s to lower 40s in colder valleys of the upper elevations to the mid 40s to around 50 degrees ( milder ridges ). Areas of valley fog.
High Knob Hellbender 10K Race Forecast
A seasonally cool but dry race is forecast this year, with some low clouds and fog possible in a layer that could stream along the base-lower portions of the massif from Powell Valley during the morning, on light SW flow, prior to dissipating into partly cloudy skies as temps warm.
Some variations in temperature along the race course this year will include a start in the 50s ( following early AM lows in the 40s ) within downtown Norton, a rise to around 60 degrees above Legion Park and below the Flag Rock Recreation Area junction with State Route 619, then a fall back into the 50s with increasing elevation above Flag Rock ( these temps for the 10:00 AM to Noon period ).
Please note that breezy SSW-SW winds at upper elevations will make conditions feel more like the upper 40s to lower 50s.
10:00 AM Start In Downtown Norton
55 degrees – A Layer of fog and clouds will be possible just above downtown, along lower slopes of the massif, otherwise partly cloudy conditions are expected.
12:00 Noon At Summit of High Knob
54 degrees ( a crisp feels-like temperature of 48-52 degrees ) beneath partly cloudy skies. SSW to SW winds of 5-10 mph, with some higher gusts.
*This forecast is a go. Good Luck to all runners & walkers!
Saturday Afternoon
Partly-mostly sunny. Winds S-SW 5-10 mph, with some higher gusts ( especially on mid-upper elevation ridges ). Temperatures varying from upper 50s to lower 60s in the upper elevations to the upper 60s to lower 70s ( warmer southward into the Great Valley ).
Saturday Night Into Sunday Morning
Partly to mostly clear. Winds SSW-WSW winds 5-15 mph, with higher gusts, on middle to upper elevation mountain ridges. Temperatures varying from 40-45 degrees in cooler mountain valleys to the lower-middle 50s.
Weather Discussion ( Autumn Changes )
A significant weather change in conditions was observed during the Tuesday PM to Thursday PM period, as noted by these dramatically contrasting views from the High Knob Massif Webcam at UVA-Wise.
High Knob Massif Webcam – University Of Virginia’s College At Wise
From pristine autumn skies to a complete obscuring of upper elevations within low clouds and dense fog ( below ).
High Knob Massif Webcam – University Of Virginia’s College At Wise
Conditions in upper elevations of the High Knob Massif were chilly prior to this radical conditions change on September 29, as noted by these readings recorded on the High Knob Massif MesoNET.
High Knob Massif MesoNET – September 27, 2016
Although green still dominates the forest, and autumn color is running well behind its typical schedule in upper elevations of the High Knob Massif, some changes are occurring and many trees are now on the brink of changing-brightening with colorations.
Early Color Changes – Northern Slopes of High Knob Massif – September 28
Note along the crest of this high ridge that some trees are flagged, a rather atypical observation for deciduous northern hardwoods versus spruce-fir crestlines ( where coniferous growth is more conducive to flagging of limbs at high elevations ).
High Knob Massif MesoNET – September 28, 2016
AM MINS dipped into the upper 30s to lower 40s within colder mountain valleys during September 28 ( 42 degrees in Clintwood ). Coldest conditions occurring in places not impacted by dense fog. Wetland valleys upstream of Big Cherry Lake having dense fog on every night so far during September in places near Beaver dams.
Black Mountain MesoNET – September 29, 2016
Note wind chills into the lower 40s have been recorded at 4031 feet elevation by the Black Mountain MesoNET, with likely somewhat lower chills at places like High Knob Meadow ( Lookout ).
Conditions in upper elevations during September 29 were simply nasty, with dense fog all day across the High Knob Massif where numerous showers ( some with thunder-hail ) held temperatures in the 40s to lower 50s during the PM.
European Model 500 MB Analysis At 8 AM Thursday – September 29, 2016
A upper-level low has cut itself off from the main jet stream flow across North America. It will be key to conditions that are observed on Saturday for the High Knob Hellbender.
NAM 12 KM Model 925 MB RH Forecast At 10 AM Saturday
Looking ahead, my forecast for this year’s grueling climb from downtown Norton to the summit level of High Knob, the infamous High Knob Hellbender 10K Race, is dependent upon the current upper-level low moving enough to allow for drier air to stream into the area.
NAM 12 KM Model Forecast Sounding At 10 AM Saturday
Should this low be slower to move than models currently indicate, which is always possible with upper-lows, then a more cloudy race could result.
