The year of 2016 was notable in that it marked the beginning of a University Of Virginia’s College At Wise study focused on defining microclimates in complex terrain. While a general climate study of the High Knob Massif area has been ongoing for nearly three decades, this project will zero in on local-scale climates across a large vertical elevation range amid complex topography. A long-term project goal being to develop a better understanding of the relationships between microclimate and terrestrial-subterranean biodiversity in heterogeneous terrain.
*The High Knob Massif and its extended landform are ideal for such a study since this is a designated center for the rarity & richness of limited range species in the continental USA ( Precious Heritage ), and is the wettest area in Virginia containing very significant terrestrial & subterranean features.
The winter of 2015-16 got off to a slow snow start, with January marking the beginning. However, falls of snow were light in the high country up until the January 22-24 period when a major storm dropped 19.0″ to 28.0″ .
This was part of a very wet period with rain and snow melt followed by another big dump of snow during February 8-11 when 10″ to 18″ fell from the City of Norton across the high country of the massif.
General 10″ to 20″ snow depths on February 15 increased a little more before milder temperatures and rain triggered yet another big run-off ( above ) from the high country.
Total precipitation during the December-February period of Meteorlogical Winter topped 25.00″ in the upper elevations ( Jan + Feb combining to produce a general 50″ to 80″ of snowfall above 3000 feet elevation in the massif ).
Although January-February snowfall was significant, the 2015-16 season was below average with a general 60-90″ above 3000 feet. By contrast, the previous Winter of 2014-15 produced nearly this much snow just during the month of February ( 56″ to 73″ ).
Meteorological Winter 2015-16 precipitation totals at the base of the massif reached 17.85″ in the City of Norton and 19.28″ within South Fork Gorge at the Big Stone Gap Water Plant. Totals lee of the mountains reached 12.67″ in the Tri-Cities.
November-April defines the Orographic Forcing Season in the High Knob Massif, with May-October denoting the Convective Season ( May & October often being transitional months with overlap between the two dominant modes ). This break-down forms the MEAN, as I teach it, with variations between years.
March turned atypically quiet with much below average precipitation and only 1-3″ of snow in the high country. April was also drier than average, especially at lower to middle elevations surrounding the massif.
*A general 4.50″ to 5.00″+ of rain fell in the upper elevations during April, with 4.64″ being measured at Big Cherry Dam.
The convective season really got going in May with wetness ruling the May-August period ( at least until mid-August ). Drier and wetter locations existed, with Appalachia Lake on the northwestern flank of the massif having significantly less rainfall than locations within and around the core of the main high country mass.
A general 25.00-30.00″ of rain fell during these 4 months within the High Knob Massif area, to contrast with much drier conditions to the south where only 12.23″ were measured in the Tri-Cities of the Great Valley.
May-August Rainfall Totals
Appalachia Lake Water Plant 18.92″
UVA-Wise NWS Station 19.80″
The Pines Near Dungannon 22.90″
City of Norton Water Plant 25.17″
*Big Cherry Lake Dam 25.80″
Big Stone Gap Water Plant 25.96″
*Rainfall was greater than measured due to evaporation between hand-measurements which average 1 per week ( however only 2 hand-measurement were made during July for more significant evaporation losses from the rain gauge at Big Cherry Dam ).
A big shift into dryness occurred as August gave way to September and the beginning of meteorological autumn, with color changes being slowed by above average temps.
The above being relative, of course, to local conditions with high valleys in the massif experiencing the first low-mid 30s during October 9-10, followed by rapid advancement of color changes.
September-November Rainfall Totals
UVA-Wise NWS Station 6.00″
The Pines Near Dungannon 6.30″
City of Norton Water Plant 7.62″
Big Stone Gap Water Plant 7.75″
Appalachia Lake Water Plant 8.47″
*Big Cherry Lake Dam 9.87″
*Approximate total with a general 10.00″ to 12.00″ of rainfall across the upper basins of Big Cherry Lake, High Knob Lake and the Norton Reservoirs ( a large percent coming in late November to keep Autumn 2016 from becoming the driest on record ).
A radical pattern change, which began in mid-November really reached its potential late in the month with wetness ruling the mountain landscape throughout December.
December Precipitation Totals
UVA-Wise NWS Station 7.07″
City of Norton Water Plant 7.95″
Appalachia Lake Water Plant 8.02″
Big Stone Gap Water Plant 8.82″
*Big Cherry Lake Dam 10.52″
*Eagle Knob 12.17″
*Approximate totals. The rain gauge at Big Cherry Dam was found busted late in the month due to low temperatures, with this final monthly total being based upon an automated rain gauge and the OBSERVED differences between it and the hand-measured NWS rain gauge in the previous five Decembers at Big Cherry Dam.
The hand-measured NWS rain gauge total reached 10.45″ in December 2015 at Big Cherry Dam. Due largely to orographic forcing, the past decade has found December to be the wettest month of the year with between 8.00″ and 9.00″ of total precipitation on average.
Going into autumn dryness the lake level was lower than it would have been normally due to a mandated, summer-long water release to help augment flow on the Powell River running downstream toward the Virginia-Tennessee border ( where longer-lived drought existed ).
A tremendous water level rise of 12 vertical feet occurred on Big Cherry Lake during 5 significant rain events between late November and the end of December.
This occurred in wake of a near flat-line representing persistent autumn dryness ( up until late November ).
Although a dozen or so rime formation days occurred in December, the month produced below average snowfall with only around 6″ at most occurring during the month. Much of that fell into December 30 amid wicked winds!
During the past 28 years an average of 19.0″ of snow fell during December in the High Knob-Eagle Knob area of the massif ( * ).
*The absurd 0.5″ during December 2015 being the least observed to contrast with 67.0″ ( if not more ) which buried the high country through December 2010 ( up from the 50.0″ or more that fell during December 2009 ).
December 2016 Climate Statistics High Knob Massif Mesonet
Eagle Knob ( NW Slope ) Elevation 4188 feet
Average Daily MAX: 39.6 degrees Average Daily MIN: 24.8 degrees MEAN Temperature: 32.2 degrees MAX Temperature: 54 degrees MIN Temperature: 4 degrees Total Precipitation: 12.17″ Total Snowfall: 6.0″
High Knob Peak
( Southern Exposure )
Elevation 4101 feet
Average Daily MAX: 40.8 degrees Average Daily MIN: 25.2 degrees MEAN Temperature: 33.0 degrees MAX Temperature: 55 degrees MIN Temperature: 4 degrees
High Knob Lake Basin
Elevation 3527 feet
Average Daily MAX: 40.6 degrees Average Daily MIN: 25.2 degrees MEAN Temperature: 32.9 degrees MAX Temperature: 57 degrees MIN Temperature: 7 degrees
Big Cherry Lake Wetland Valley 1
Elevation 3218 feet
Average Daily MAX: 41.8 degrees Average Daily MIN: 23.6 degrees MEAN Temperature: 32.7 degrees MAX Temperature: 59 degrees MIN Temperature: 6 degrees
Big Cherry Lake Wetland Valley 3
Elevation 3174 feet
Average Daily MAX: 42.3 degrees Average Daily MIN: 23.0 degrees MEAN Temperature: 32.6 degrees MAX Temperature: 59 degrees MIN Temperature: 5 degrees
2016 Precipitation Totals
Orographic forcing played its typical role in the
distribution of precipitation during 2016, as did
convection, with notable enhancements observed
amid the lifting zone of the High Knob Massif.
Totals topped 70.00″ within the upper elevations
across heads of basins containing High Knob Lake,
Big Cherry Lake and the Norton Reservoirs.
Big Cherry Lake Dam ( Elevation 3120 feet )
Total: 68.85″ ( M )
Although the NWS hand-measured rain gauge was supplemented with snow core data during the winter, and with IFLOWS data in periods of lost data, the total for the year is still below what fell due to evaporation between hand measurements & wind induced rain gauge undercatches.
Big Stone Gap Water Plant ( Elevation 2018 feet )
City of Norton Water Plant ( Elevation 2342 feet )
The 2016 total at Norton Water Plant was -1.52″ below the average observed during 1983-2013. During that 31 year period the plant had missing data in the cold seasons from 1983-1998 when a 4″-diameter NWS rain gauge being used was too small to contain the larger falls of snow ( a 8″-diameter NWS rain gauge was put in place at Norton WP during Summer 1998 ). The below average departure for 2016 ( with respect to the past 30+ years ) is somewhat greater than indicated by the -1.52″ value.
A couple of NWS Cooperative stations located along the Tennessee Valley Divide, and outside the main lifting zone of the High Knob Massif with respect to prevailing SW air flow trajectories, had much less precipitation in 2016.
University Of Virginia’s College At Wise – NWS Staion ( Elevation 2550 feet )
( -3.39″ below 1981-2010 average )
*A station move from Wise 3 E back to the campus of UVA-Wise occurred with retirement of veteran observer Roy L. Wells, Jr., following more than 50 years of diligent observations, during Spring 2016 ( the NWS station was on the campus of UVA-Wise, formerly called Clinch Valley College, for nearly 40 years ).
Nora 4 SSE NWS Station Long Ridge of Sandy Ridge ( Elevation 2650 feet )
Nora 4 SSE is located east-northeast of the Wise Plateau along the Tennessee Valley Divide and the adjoining Sandy Ridge Plateau in extreme southern Dickenson County and is operated by observers Wayne & Genevie Riner.
Sunday was a LONG day for me. After doing my nightly forecast it was up early to meet my buddy Roddy Addington at the City of Norton Water Plant for a run at the summit.
I measured 4″ to 6″ of snow depth at the Norton Water Plant, with widespread snow across all of the northern slopes. Some patches of packed ice did not bode well for me and Rod. I brought chains.
As it turned out, even with winds that sounded like a JET, the trip upward was pretty good with only a few patches of ice and packed snow. No chains needed for this stretch.
Snow depths of 6″ to 10″ were widespread, with 8″ being the mean I obtained by doing many measurements. Snow drifts of 1-2+ feet remained in many places along the high ridges, with local depths upwards of 3 feet.
Depths by today had diminished greatly, of course, and were only 1/3 to 1/2 what they were back on January 23.
The high country had a solid snow cover, even though air temperatures had been well above the freezing point for more than 30 consecutive hours.
*Taking photographs was made more difficult by ROARING SW winds that would blow your tripod and camera over without holding to them ( at least mine ). Temperatures in the lower 40s, combined with 30-50 mph gusts, to push wind chills into the 20s at times. Enough to make multiple layers of cloths, gloves, and anything else one could wear feel pretty good.
Observe the frozen, ice covered surface of High Knob Lake in the high valley near lower left center of photograph. All lakes amid the massif are frozen ( but ice was bobbing up and down in the ROARING SW winds at the Upper Norton Reservoir ).
The cloud line visible in my photograph above showed up well on NASA visible imagery, as did nice orographic wave clouds which were visible on satellite images and from the Lookout Tower.
The High Knob Massif covers approximately 182 square miles and nearly all of it ( except for portions of the Powell Valley ) were still covered by snow on this last afternoon of January 2016.
My hands & face were very cold from ROARING SW winds, and from digging out an area in order to take a good, clean sample.
I took several snow cores, both to see how much water was still present and to help better determine how much precip and snow actually fell atop the massif during the snowy period from January 17-27 ( with one rain event ).
Snow Core Data – January 31, 2016
8″ Depth = 5″ Core With Compression Into Tube Water Equivalent was 2.15″
22″ Depth = 15″ Core with Compression Into Tube Water Equivalent was 7.20″
I used an official National Weather Service 8″-diameter inner measuring tube to take the cores. Snow was hard enough to at least partially walk on top of in many places, such that the snow depth compressed in the tube upon working it down through the relatively hard snow. I used a large, flat spade to dig out around where I would take the cores, then worked the flat blade of the spade beneath the snow. This tends to generate a nice core upon working the tube down through the snow to the spade. One can generally obtain nearly all the snow by using this method. I like nice, clean cores and will reject them if they are not ( the lower portion of the snowpack was harder than the top layer ).
The cores ended up being relatively consistent in nature, varying from 0.27″ to 0.33″ of water content per 1″ of uncompressed snow.
Snow depths on January 23 reached a mean of 2 feet or more in the main crest zone of the massif. One rain event during January 26 added to the water content of the snowpack.
*Rime deposition and drop from trees occurred during the January 17-25 period, but was not excessive in nature as observed during past events.
Snowfall amid the main crest zone was enhanced by a TIM Circulation which I first discovered many years ago. In this case, the final result yielded a snow gradient that varied from 2+ feet of total snowfall within the main crest zone to only 3″ of depth ( 4″ or so of snowfall ) around 10 air miles away in portions of Big Stone Gap ( most of the accumulated snow in Big Stone Gap coming via NW-NE flow, with approximately half the snow that fell atop the massif via this northerly upslope flow ).
A drive along Route 238 past High Knob Lake junction got snowpacked and icy, with only an ATV appearing to have broken the snow. Rod and I decided to turn around and head back down State Route 619. This ended up being the right call, as some beautiful photographs were taken upon reaching the Upper Norton Reservoir as sunshine finally returned to aid reflections upon ice!
Beautiful scenes abounded at the Upper Norton Reservoir.
Snow depths in Benges Basin of the Upper Reservoir varied from bare ground on well exposed slopes to a general 3″ to 12″+ on the trail which runs along the northern side of the lake.
A rather amazing day in the High Knob Massif given bare ground and 60+ degree temperatures observed during the weekend amid the Great Valley and the Tri-Cities!