Wednesday, January 27, 2010

Whitewater GUSHES - January THAW 2010

Misty vapors rise above the rock filled chasm of
Class V+ ( super-extreme ) South Fork Gorge.

January 25, 2010
South Fork Gorge of High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

Turbulent, churning whitewater gushed downward through awesome depths of South Fork Gorge as pristine water drained lofty Big Cherry Basin of the High Knob Massif during a break from winter's frozen grip upon its highcountry domain!

Captured by photographer Roddy Addington during January 25, only twelve days removed from 1-2+ FEET of snow depth ( an atypically LONG thaw during what promises to be a HARSH winter amid the southern Appalachians ).

High Knob Massif
South Fork of Powell River
Whitewater & Rocks - January 25, 2010
Photograph by Roddy Addington - © All Rights Reserved.

Dropping 1433 vertical feet in 4 miles
1069 feet during its final 2 miles, and containing two sections having max gradients up to 800+ feet per mile, great South Fork Gorge possesses one SUPER-TIGHT and SUPER-EXTREME steep creek!

[ Its only EYE CANDY for whitewater kayakers at the moment, as even before a MAJOR December 2009 snowstorm downed more trees it was FULL of wood!

But its there, and the POTENTIAL is real, VERY REAL, despite the hold back of large volumes of water by Big Cherry Dam ].

Between 80" and 90" of total precipitation fell across Big Cherry Basin during 2009 to keep water overflowing the Dam nearly all year.

Based upon City of Norton records, the wettest 12-month period since the early 1980s would have produced 90-100" across Big Cherry Basin, so 2009 was NOT a record wet year.

[ The above being gage caught precipitation, as the TRUE moisture budget of this highcountry basin is MUCH greater via FOG DRIP from trees, RIME deposition on trees, and the obvious loss of gage measurable precipitation due to wind driven precip ( reducing what is recorded digitally and by hand ) ].

Gushing thaws from deep winter snowpacks are not uncommon.

Reference the following section of this website for another example:

January 25, 2010
Most Tranquil Stretch In South Fork Gorge?
Photograph by Roddy Addington - © All Rights Reserved.

**For more incredible Roddy Addington WHITEWATER shots please reference:

This most recent rainfall event of Jan 24th, generated 7 to 8 vertical feet of total rise on both the Powell & Clinch rivers ( world-class biodiversity hotspots), downstream of whitewater creeks draining the High Knob Massif in Lee and Scott counties of southwestern Virginia.

Little Stony Basin of Clinch River
Big Falls - Little Stony Gorge of High Knob Massif
Photograph by Johnny Stanley - © All Rights Reserved.

Little Stony Gorge contains one of the most complete whitewater runs in the eastern United States, with Class IV-V+ rapids draining a 16.4 square mile watershed with more than 2100 vertical feet of total relief ( Little Stony Basin ).

[ Little Stony Gorge lies approximately 15 air miles E to ENE of South Fork Gorge, adjacent to majestic Guest River Gorge and the eastern end of the High Knob Massif ].

The Big Stony Basin multi-gorge wonder complex is situated in between South Fork Basin and Little Stony Basin, with 42 square miles of terrain so remote and rugged that few photographs ( of high quality ) even exist to illustrate its nearly 3000 vertical feet of total relief ( it is drained by extremely steep whitewater creeks amid Straight Fork Gorge, Chimney Rock Gorge, and Mountain Fork of Big Stony Gorge ). 

Up to 3.00"+ of rain accumulated along the Cumberland Mountain arm of the High Knob Landform ( HKL ), across Cumberland Gap National Historical Park, during January 24 to help boost the Cumberland River into minor flooding.

Calcareous Core of High Knob Landform
South Fork Gorge from Powell Valley Floor
Photograph by Roddy Addington - © All Rights Reserved.

South Fork Gorge rises upward and twists back behind mountain walls visible in the above scene, themselves being MUCH lower than highcountry crestlines which sprawl outward across the massif, to generate a watershed with nearly 2800 vertical feet of total relief ( South Fork of Powell Basin ).

[ The South Fork of the Powell River drains 41 square miles of the High Knob Massif on the Wise County side of the highcountry.  Collectively, the Big Stony Basin, Little Stony Basin, and South Fork Basin contain 99.3 square miles ( many more basins are present within the domain of the great High Knob Massif ) ].

Rising Into The Heavens - January 22, 2009
Photograph by Roddy Addington - © All Rights Reserved.

The High Knob Massif can handle more total precipitation, without flooding ( rainfall and/or rain + snow melt ), than other locations across western Virginia since most creeks draining its highcountry sink, or partially sink, into the subterranean prior to reaching regional base levels marked by the Clinch and Powell rivers.

Reference "The High Knob Landform" to learn more about these world-class karst systems

Another factor making the High Knob Massif unique to Virginia, and the southern Appalachians, is that many of its higher elevation basins have lakes and wetlands which themselves hold back much water from direct run-off into creeks.

A Few Notable Ones Include:
High Knob Basin Wetland: 3500'+
High Knob Lake: 3490'
Upper Norton Reservoir: 3308'
Lower Norton Reservoir: 3230'
Cliff Mountain Ponds: 3155-3205'
Big Cherry Basin Wetlands: 3125-3200'
Big Cherry Lake: 3120'
Wolf Creek Wetlands of Stock Creek: 3000'
Glady Fork Wetlands of Big Stony Basin: 2900'
Robinson Fork Wetlands: 2740'+
Bark Camp Lake: 2734'

[ There are numerous additional small ponds, wetlands, and seepages within the High Knob Massif on both private and USFS public lands ].

Cloud Vapor Gathering Above Massif - January 25
Photograph by Roddy Addington - © All Rights Reserved.

Once very extensive underground conduit systems become full of water, lakes and wetlands fill and overflow, extremely flashy situations can then develop with excessive rainfall, rapid snow melt, or a combination of rainfall + snow melt.

This makes the High Knob Landform hydrologically complex, with flooding more often than not being associated with rapid water level rises during flashy events ( the obvious exceptions being downstream along the Clinch and Powell rivers, which take longer to reach peak levels, and during historic events like the great floods of February 1862, January 1957, and the benchmark disaster of April 1977 ).

Changing Conditions - January 25, 2010
Photograph by Roddy Addington - © All Rights Reserved.

A distant snow shower obscures part of the lofty highcountry, as a hole opens in the overcast above Powell Valley to reveal PUFFY clouds rising vertically into blue heavens!

[ Some of these clouds generated lightning & thunder, with localized THUNDERSNOW during late afternoon hours of January 25 in parts of Wise and Dickenson counties ].

Rainbow Across The Valley - January 25, 2010
Photograph by Roddy Addington - © All Rights Reserved.

Majestic and unusual looking rainbows were also part of weather conditions observed, as the THAW gave way to returning cold air.

Majestic Double Bows Grace Lee County
Photograph by Harold Jerrell - © All Rights Reserved.

My friend Wayne Riner captured one of the most unusual looking rainbows amid the highlands of southern Dickenson, adjacent to the High Knob Landform.

Burst of Morning Color - January 25, 2010
Photograph by Wayne Riner - © All Rights Reserved.

Wayne described the scene in his own words:

"While in the yard, I noticed a burst of color on a distant ridge. This was the only part of the rainbow that was visible. There were rain showers and sun in the area at the time. I felt it was very odd to see such a bright patch of color and no other sign of the rainbow."

A most glorious ending to January THAW 2010!

This website update is dedicated to the wonderful, beautiful Gladys Stallard, who turns 97 years young today ( January 27 ).

Happy Birthday Gladys!

May you have MANY more.

Rainbow - Cumberland Gap National Historical Park
Photograph by Harold Jerrell - © All Rights Reserved.