Saturday, July 12, 2014

Majesty In Big Cherry Basin & South Fork Gorge


July 11, 2014
Powell River Watershed of High Knob Massif
Majestic High Country of Big Cherry Lake Basin
Photograph by Wayne Browning - © All Rights Reserved.


Solitude and beauty of cascading whitewater filled the cliff laden chasm of South Fork Gorge during July 11 as pleasant breezes warmed the sprawling high country surrounding Big Cherry Lake.

Continuous sounds of gushing whitewater accentuated settings
of photos 1, 3, and 5 in the picture viewer, adding greatly to the
majesty of this special watershed whose wildness offers forth
a bounty of precious water to all creatures great and small ( # ).

#South Fork of Powell River contains a 40 square mile watershed which is a high conservation area for the Town of Big Stone Gap, and surrounding region, upstream of Big Stone Gap Water Plant into the head of Big Cherry Lake basin and the High Knob peak.

This is part of a very rich Mixed-Mesophytic Forest possessing many diverse natural communities, both above and beneath the surface!

Reference South Fork of Powell River in
this section to view the diversity of species
indicated by awesome autumn colorations:

Early Autumn Color Changes In High Knob Massif

July 11, 2014
High Knob Massif
Upper Tennessee River Basin
Rugged Majesty of South Fork Gorge
Photograph by John Mullins - © All Rights Reserved.

( Updated July 21, 2014 )
Monthly Precipitation Totals
Big Cherry Dam of High Knob Massif
Observer: Gary Hampton & Staff of Big Stone Gap WP
Elevation 3120 feet

January: 4.68"

February: 6.16"

March: 5.35"

April: 3.54"

May: 3.59"

June: 5.07"
 ( -1.03" below 6-year June average )

**July 1-21: 6.07"

2014 Total: 34.46" ( M )*
   ( January 1 to July 21, 2014 )

  -7.60" below the January-June average
  observed during the 2008-2013 period

 *The NWS rain gauge busted due to extreme coldness in January
with the late January-February total being partially based upon
an automated IFLOWS rain gauge at the Dam ( with missing data ).

    Actual 2014 total is estimated to be around 36.07" due to missing moisture in snow too deep for the rain gauge to physically contain and between hand-measurements at the Dam throughout the year
( averaging 1 measurement per week ).

**Reported July 1-21 rainfall totals reached 5.71" at Upper Norton Reservoir, amid Benges Basin of the High Knob Massif, and 7.04"
on Robinson Knob above Bark Camp Lake where up to 16.00"+
of rain have fallen since June 1.

This is part of the wettest area in Virginia.  Reference the Climatology Section of 
The High Knob Landform for details. 

July 11, 2014
Downstream of Big Cherry Dam
Wild Upper Reach of South Fork Gorge
Photograph by Wayne Browning - © All Rights Reserved.

Downstream of Big Cherry Dam the wild upper reaches of South Fork Gorge spread outward between Long Hollow and Little Mountain in southwest Wise County, Va., above a cliff lined transition from mixed Bluestone Formation rocks of Upper Mississippian aged sandstone-limestone stratigraphy to resistant quartz-arenite dominated Lower Lee Formation rocks of Pennsylvanian age.

Calcareous clays & carbonate nodules are embedded within
dominant sandstone & shale sequences of the Mississippian
aged Bluestone Formation.

July 11, 2014
High Knob Massif
Rugged Cliffs of South Fork Gorge
Near Mississippian-Pennsylvanian Transition
Photograph by Wayne Browning - © All Rights Reserved.

Many Canadian Hemlock ( Tsuga canadensis ) trees continue to be infested and killed by the Hemlock Woolly Adelgid (  Adelges tsugae ).

Some trees continue to look healthy.  It is hoped that enough will survive this infestation to rebuild the population again ( up to 80% or more have died in areas infected since the 1980s to the east ).

Small Hemlocks are more healthy appearing verses large trees in most cases.  This is not the first time Hemlocks have been driven to near extirpation.  Around 5000 years ago a major decline occurred in the species across its range as indicated by paleoecological studies.

Hemlock's Future In Context Of Its Past History

July 11, 2014
Upper Reaches of South Fork Gorge
Canadian Hemlock Tree Mortality 
Photograph by Wayne Browning - © All Rights Reserved.

Hemlock Woolly Adelgids were first discovered in this area during 2007-08, having been confined to locations along and east of the
Blue Ridge for more than 50 years.  Their west spread across the Appalachians being coincident with a lack of harshly cold weather
( MINS of -20 below zero or lower ) since the middle 1990s and
the flip of the Atlantic Multidecadal Oscillation ( AMO )
into a positive phase.

South Fork of the Powell River twists southwest through this wild, boulder filled valley with a lateral stream erosion & undercut tendency being forced by southeastward dipping rock stratas during the first 2 miles below Big Cherry Dam. 

Drop Gradient Below
Big Cherry Dam:

Mile 1:    42 feet
Mile 2:  322 feet
Mile 3:  567 feet
Mile 4:  502 feet

1433 feet of drop in 4 miles

South Fork Gorge - American Whitewater Class V+

This setting changes dramatically on 
Miles 3 & 4 downstream of Big Cherry Dam as 
a northwesterly stream flow begins to intersect southeastward dipping bedrock layers.  Lateral stream erosion and undercutting, indicative of Miles 1 & 2, gives way to downcutting from one layer to the next to form ledges with significant variations in both spacing and vertical depth.

A classic steep creek results that is merely a single product of this fascinating and unique geological and climatic setting.

July 11, 2014
Water Elevation 3120 feet
Big Cherry Lake of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved.

Dead trees standing on edges of Big Cherry Lake are mostly
post-dam related dying due to a rise in water levels following construction of the new Dam during 2005.  In some cases it is
likely related to the Hemlock infestation.

July 11, 2014
Big Cherry Lake of High Knob Massif
Standing Dead Trees Along Lakeshore
Photograph by Wayne Browning - © All Rights Reserved.

Great Rhododendrons ( Rhododendron maximum ) were in
heavy bloom around the Lake and portions of South Fork Gorge.

Lake water has overflowed Big Cherry Dam throughout 2014 with exception of some days in June and July when levels were just beneath the spillway top ( ** ).

**A total of 41.687 Million gallons of water were
discharged from the Lake during June 2014
( does not include natural spillway overflow ).

Recorded Precipitation

Past 18 Months: 102.77" ( M )
( January 2013 - June 2014 )

Average per Month: 5.71" ( M )

( M ) - Indicates missing moisture in snow too deep for the rain gauge to physically contain and between hand-measurements at the Dam throughout the year.  Approximate actual total, if it had been possible to measure daily, was around 108.00" or 6.00" per month during the past 18-months.

Much more rain fell east to northeast of Big Cherry Dam during the May 1 to July 11 period of 2014, with greatest amounts impacting watersheds containing Bark Camp Lake and adjacent 
communities ( # ).

#Wet-dry feedbacks have impacted the rainfall pattern during
the warm season of 2014, as typically occurs, with 2014 featuring tendencies toward wet feedbacks on the High Chaparral, Robinson Knob, and Coeburn side of the massif verses drier feedbacks on the Norton to Big Cherry Dam side.  All areas within the massif have received 10.00" to 17.00" of rainfall during May 1 to July 11, such that wet-dry feedbacks are relative to wetter verses drier places and not indicative of important drought stress.

July 11, 2014
View From Big Cherry Lake Road
Little Stone Mountain of High Knob Massif
Photograph by Wayne Browning - © All Rights Reserved.

The Maple Gap road, State Route 722, 
offers gorgeous views of South Fork Gorge.

July 11, 2014
Looking Toward Long Hollow & Huff Rock
Maple Gap Karst Fields of High Knob Massif
Photograph by John Mullins - © All Rights Reserved.

The basin of Big Cherry Lake spreads outward for miles
beyond the highest crestline visible in this photograph,
forming part of the crest zone of the High Knob Massif.

My friend & photographer Roddy Addington 
has beautifully illustrated these scenes during 
different seasons in past years.

July 11, 2014
Looking Up South Fork Gorge
Mountain Farm Along Maple Gap Road
Photograph by Wayne Browning - © All Rights Reserved.


Chilly July Spells
Punctuated By Heavy Rain Events

July 2014 has been characterized by heavy rain events separating spells of unseasonably cool air.

For a review of the first cool spell of July 2014, and subsequent heavy rain event, please reference:

Gorgeous Independence Day In Appalachians

A few days after July 8-10 rains another surge of showers and downpours in booming storms dominated the July 13-15 period.

High Knob Massif Area
Reported Rainfall Totals
July 13-15, 2014

Downtown Coeburn: 1.52"

Robinson Knob: 1.76"

Little Stone Mountain VDOT: 1.77"

Big Cherry Dam: 1.85"

Lower Norton Reservoir: 1.92"

Upper Norton Reservoir: 2.07"

Downtown Appalachia: 2.42"

July 16, 2014 at 2:49 PM
CAM Elevation 2600 feet
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

An air mass analogous to Independence Day followed with MIN temperatures dropping into 
the 40s during morning hours of July 16-17.

Chilly air aloft generated abundant cumulus during both days.

July 17, 2014 at 3:34 PM
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

Morning hours of July 17 were coolest with 
40 to 45 degrees in mountain valleys of 
mid-upper elevations ( above 2000 feet ).

These were not record lows, at least for high mountain valleys, according to the long database in Burkes Garden where record minimums occurred during 1926 with 31 degrees on July 16
and 37 degrees on July 17.

July 18, 2014 at 2:23 PM
Engulfed Within The Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

Clouds and all day soaking rain held afternoon MAX temperatures to only 50s atop the High Knob Massif and to 62 degrees in the City of Norton on July 18.

The next big rain event developed July 18-19 with more long-lived pilatus capping the High Knob Massif on breezy-gusty S-SE winds.

July 19, 2014 at 2:53 PM
Orographic Cap Clouds ( Pilatus )
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

Preliminary rainfall totals of 2.50" to 3.00" occurred on S-SE upslope across Big Cherry Lake basin and the windward side of Black Mountain along the Virginia-Kentucky border (***).

***This was confirmed by Gary Hampton, Superintendent of the Big Stone Gap WP, who measured 2.95" at Big Cherry Dam where around 1/2 feet of water was overflowing the spillway July 21.


Summer Wetness 2014
High Knob Massif Area

July 2014
Wise County, Virginia
Summer Majesty In Cumberland Mountains
Photograph by Roddy Addington - © All Rights Reserved.

Rod Addington Photography

An abundance of summer rainfall has soaked the High Knob Massif since the start of Meteorological Summer on June 1, with significant variations in amounts over short distances.

June 2014: Wet & Mild In High Knob Massif Area

The pattern producing this wetness actually
started around the middle of May 2014.

High Knob Massif Area
Reported Rainfall Totals
June 1 to July 21, 2014

City of Norton WP: 8.50"

Nora 4 SSE: 8.54"

Fort Blackmore 4 SE: 10.95"

Big Cherry Lake Dam: 11.14"

Clintwood 1 W: 11.29"

Little Stone Mountain Gap: 11.43"

*Lower Norton Reservoir: 12.29"

Town of Coeburn: 12.44"

*Upper Norton Reservoir: 13.33"

*Part of a wet corridor from upper Big Cherry Lake basin
east into headwaters of Bark Camp Lake basin with general
12.00" to 16.00"+ rainfall amounts during June 1-July 21.

Parts of this corridor represent the only places in Virginia
to have reached 40.00" or more of precipitation up to this
point in 2014 ( January 1-July 21 ).

July 18, 2014
View From Powell Valley Overlook
Clouds Hang Low Across High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

High Knob Massif Area
Reported Rainfall Totals
May 1 to July 21, 2014

Nora 4 SSE: 12.50"

City of Norton WP: 13.55"

Fort Blackmore 4 SE: 14.23"

Big Cherry Lake Dam: 14.73"

Little Stone Mountain Gap: 15.59"

Town of Coeburn: 15.75"

Clintwood 1 W: 16.07"

Lower Norton Reservoir: 17.40"

*Upper Norton Reservoir: 19.21"

*Up to 21.00"+ of rainfall during May 1-July 21
in headwaters of the Bark Camp Lake basin.

An often observed precipitation gradient has again developed this year across southwest Virginia, with wetter places in the High Knob Massif receiving more rainfall since May 1 than many places have observed all year ( since January 1 ) northeast, 
east, and south of the Cumberland Mountains.

( Mercer County Airport )
Bluefield ( WV )
July Rainfall: 1.40"
Rain Since June 1: 5.00"
Rain Since May 1: 7.80"
2014 Precipitation Total: 16.66"

( Pulaski County )
Radford 3 N
July Rainfall: 1.30"
Rain Since June 1: 2.91"
Rain Since May 1: 6.01"
2014 Precipitation: 16.94"

( Summers County )
Alderson ( WV )
July Rainfall: 1.30"
Rain Since June 1: 3.21"
Rain Since May 1: 5.86"
2014 Precipitation Total: 17.41"

( Carroll County )
Galax WTP
July Rainfall: 2.15"
Rain Since June 1: 3.60"
Rain Since May 1: 7.99"
2014 Precipitation: 17.44"

( Allegheny County )
Gathright Dam
July Rainfall: 0.67"
Rain Since June 1: 2.41"
Rain Since May 1: 6.46"
2014 Precipitation Total: 17.56"

( Summers County )
Bluestone Lake ( WV )
July Rainfall: 1.04"
Rain Since June 1: 4.90"
Rain Since May 1: 7.64"
2014 Precipitation Total: 18.06"

( Wythe County )
Wytheville 1 S
July Rainfall: 1.26"
Rain Since June 1: 4.78"
Rain Since May 1: 7.71"
2014 Precipitation Total: 18.22"

( Highland County )
Millgap 2 NNW
July Rainfall: 0.77"
Rain Since June 1: 2.54"
Rain Since May 1: 6.30"
2014 Precipitation: 18.47"

( Sullivan County )
Tri-Cities ( TN )
July Rainfall: 3.20"
Rain Since June 1: 6.78"
Rain Since May 1: 8.98"
2014 Precipitation Total: 18.78"

( Tazewell County )
Burkes Garden
July Rainfall: 2.07"
Rain Since June 1: 5.76"
Rain Since May 1: 8.40"
2014 Precipitation: 19.21"

( Montgomery County )
Blacksburg
July Rainfall: 1.56"
Rain Since June 1: 4.63"
Rain Since May 1: 7.31"
2014 Precipitation: 19.46"

( Raleigh County )
Beckley ( WV )
July Rainfall: 1.52"
Rain Since June 1: 5.38"
Rain Since May 1: 9.25"
2014 Precipitation: 19.50"

( Smyth County )
Saltville 1 N
July Rainfall: 2.45"
Rain Since June 1: 6.62"
Rain Since May 1: 10.37"
2014 Precipitation: 20.98"

( Mercer County Coop )
Bluefield ( WV )
July Rainfall: 1.34"
Rain Since June 1: 6.99"
Rain Since May 1: 10.46"
2014 Precipitation: 21.19"

These statistics show an amazing contrast in
precipitation amounts this year, and have been
replicated many times during past years between
the High Knob Massif area and places to the east
and northeast across Virginia & West Virginia.

Even more extreme, consider July 2014 
differences between these cities in Virginia:

Climate Statistics
For July 1-21, 2014

( Fall Line of Piedmont-Tidewater )
City of Richmond - Elevation 167 feet
Average Daily MAX: 91.0 degrees
Average Daily MIN: 69.8 degrees
July 1-21 MEAN: 80.4 degrees
Highest Temperature: 100 degrees
Lowerst Temperature: 60 degrees
Lowest MAX Temperature: 82
Days At/Above 90 degrees: 12
July Rainfall: 0.43"
Rain Since June 1: 3.82"
Rain Since May 1: 6.26"
2014 Precipitation: 19.86"
 ( -3.94" below 1981-2010 )

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 76.8 degrees
Average Daily MIN: 54.3 degrees
July 1-21 MEAN: 65.6 degrees
Highest Temperature: 85 degrees
Lowest Temperature: 44 degrees
Lowest MAX Temperature: 62
Days At/Above 90 degrees:  0
July Rainfall: 4.42"
Rain Since June 1: 8.50"
Rain Since May 1: 13.55"
2014 Precipitation: 29.12"
( -5.60" below 1983-2013 )


( Updated July 24-25, 2014 )
Autumn-Like Cold Frontal
Passage In Mid-Summer
( July 24, 2014 )

July 24, 2014 at 7:00 AM
View from Powell Valley Overlook
Remnant Massif of High Knob Landform
Morning Fog Amid Powell Valley of Wise County
Photograph by Roddy Addington - © All Rights Reserved.

This day began like many with a gorgeous array of fog lapping up against sides of the calcareous core of the High Knob Landform, but quickly changed as heavy rain producing storms gave way to lowering cloud bases and upsloping NW-NNW winds that engulfed its high country amid a different type of dense cloud vapor!

July 24, 2014 at 1:45 PM
Obscured In Heavy Rain-Thunder
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

It is not unusual for the High Knob Massif to 
be obscured in summer during showers and downpours in thunderstorms like occurred 
amid early afternoon hours of July 24.

July 24, 2014 at 4:23 PM
Obscured In Upslope Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

What followed, however, was atypical for the middle of summer with dropping temperatures, shifting WSW to NNW winds and a widespread lowering of cloud bases over and upstream of the massif on upslope flow like is so common during the COLD season ( this is still July? ).

July 24, 2014 at 4:47 PM
Obscured In Upslope Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

The difference, of course, being that dense fog 
( clouds ) became widespread above 2000-2500 feet and prolonged in nature for hours behind 
the cold frontal passage and not just associated with local upslope driven by thunderstorms.

July 24, 2014 at 5:54 PM
Obscured In Upslope Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

A chilly drizzle accompanied the fog as afternoon temperatures dropped into lower 60s in Norton 
and Wise, with 50s above 3000 feet across the 
High Knob Massif.  Just like an autumn setting!

July 24, 2014 at 6:42 PM
Obscured In Upslope Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

More hefty rain totals drenched northern slopes of the massif with heaviest amounts noted from the head of Big Cherry Lake basin east toward 
Guest River Gorge and West Dante.

July 24, 2014 at 7:14 PM
Obscured In Upslope Clouds
Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

( City of Norton Rain Gauges In Benges Basin )
Reported Rainfall Totals
May 1 to July 25, 2014

( Elevation 2342 feet )
Norton Water Plant
July 24 Rain Total: 1.45"
July Rainfall Total: 5.87"
Rain Since June 1: 9.95"
Rain Since May 1: 15.00"
2014 Precipitation: 30.57"

*( Water Elevation 3239 feet )
Lower Norton Reservoir
July 24 Rain Total: 1.70"
July Rainfall Total: 6.07"
Rain Since June 1: 14.01"
Rain Since May 1: 19.12" ( M )

*( Water Elevation 3318 feet )
Upper Norton Reservoir
July 24 Rain Total: 1.69"
July Rainfall Total: 7.42"
Rain Since June 1: 15.04"
Rain Since May 1: 20.92" ( M )

*Elevation above sea level at full capacity.
( M ) - Indicates one missing event during May
that produced 0.72" at Norton Water Plant.

Elevation 4189 feet
July 24, 2014 at 7:13 PM
High Knob Massif Crest Zone
Head of Benges Basin - Powell River
Eagle Knob Communications Area
Photograph by Steve Blankenbecler - © All Rights Reserved.

This event pushed the July rainfall total to more than 9.00" in the Robinson Knob community of the High Knob Massif ( ** ).

**A total of 7.56" reported by the Robinson Knob IFLOWS = 9.69" if using the mean observed difference between this IFLOWS and daily hand-measured amounts in Robinson Knob during six July's from 2006-2012.  NWS hand-measured rain gauge data courtesy of residents Otis & Nancy Ward.

Midnight To 10:00 PM on July 24, 2014
City of Norton Automated Weather Station
( Norton AWS Rain Gauge Reads Around 20% Low )

For more information reference:

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