Tuesday, March 24, 2015

Wet March 2015 & Virginia Precip Differences


March 9, 2015 at 6:08 PM
Head of High Knob Lake Basin
Northern Slopes of High Knob Massif
General 10-15" of Snow Depth Following Flooding
Photograph by Wayne Browning - © All Rights Reserved.

Water from heavy rain running down trees had melted rings around tree bases throughout the northern woods, which had been wind blasted with many tiny fragments visible in the snowpack from strong wind speeds of recent days.




A general 10" to 15" of snow depth, with 18" to 30" in places, remained across northern exposed slopes of the High Knob Massif in wake of extensive flooding during the first week of March 2015.

High Knob Massif
March 9, 2015 at 7:18 PM
Head of Big Cherry Lake Basin
Walking On Top Of 30" Of Snow Depth
Photograph by Wayne Browning - © All Rights Reserved.

This was a true snowpack with bottom snow from January 2015 lingering amid the high country of this great massif.  Snow was packed so hard that I could walk on top of up to 30" of depth without breaking through, at least in places.

*A most impressive feat given 4.00" to 5.00" of precipitation 
( largely rain ) during March 1-6 and loss of up to 30" or more of total snow depth.

The snow depth loss by afternoon of March 9, from near MAX depths reached late on February 21 into February 22, can be illustrated by these images from Eagle Knob.

February 21, 2015 at 9:05 PM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

These images from my friend Cody Blankenbecler illustrate how much snow had already disappeared on Eagle Knob by the time I measured snow depths during March 9 ( around 30" of depth had melted at snow markers on Eagle Knob ).  Note how depths change along the chain-link fence by clicking back and forth in the picture viewer.

March 9, 2015 at 4:12 PM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

A snow core taken on 11" of depth produced 5.20" of water content on March 9, with general 4.73" to 7.09" of water contained in the general snowpack 
( locally much more in deep areas ).

March 9, 2015 at 6:48 PM
State Route 619 Visible In Distance
Deep Snow Across High Knob Lake Basin
Photograph by Wayne Browning - © All Rights Reserved.

This was a tenacious snowpack and one of the most difficult to fully melt away that I had seen in years, likely due to its layered development over time and high water content.


A generalized snowpack profile from the end of February, that I made of the snowpack in Clintwood, was applicable to the deeper, wetter snow in the High Knob Massif.

High Knob Lake Basin
March 9, 2015 at 6:01 PM
Looking North Toward The High Knob Lookout
Photograph by Wayne Browning - © All Rights Reserved.

The widespread nature of the snowpack left on March 9 was clearly visible from the new High Knob Lookout Tower.

March 9, 2015 at 6:47 PM
Looking Southeast From High Knob Lookout
Photograph by Wayne Browning - © All Rights Reserved.

The ice covered surface of High Knob Lake is partially visible near center of the above photograph, with a small section of ice covered Big Cherry Lake shown in a picture below.

March 9, 2015 at 6:45 PM
Looking Southwest From High Knob Lookout
Photograph by Wayne Browning - © All Rights Reserved.

March 9 was amid the great melt down period with high water volume on steep creeks draining the massif for days following this time as snow melted slowly ( thankfully ) and more rain fell to push creeks to near or locally above flood stage again.

The NWS Forecast Office In Morristown, Tn., made the wrong call by not issuing a flood watch for all this snow melt, with water around homes in the Tacoma area and in other places along creeks draining the massif during March 10-11.  A flood watch was properly issued in advance for the significant flooding observed during early March, which was an excellent call by the MRX NWSFO.

*If creeks do not need watching then a Flood Watch or Flash Flood Watch is not needed.  If creeks need to be watched by residents, then clearly a watch is needed.  In this case, there was no question that creeks needed to be closely watched in Wise, northern Scott & Lee counties.

March 9, 2015 at 6:47 PM
Lookout SW Across High Country
Small Portion of Ice Covered Big Cherry Lake
Photograph by Wayne Browning - © All Rights Reserved.

Main-stem rivers remained well below flood stage during this secondary run-off period when it was headwater creeks that rose to within a foot or less of flood stage.

March 10-12, 2015
Big Stony Creek Stream Levels
Big Stony Creek was 11" below flood stage
at the stream gauge point recorded above

When levels on steep creeks draining the massif reach those shown above they ROAR and are so loud that you can not hear somebody talking standing right beside you.

It is a very powerful experience to witness and I encourage anyone who has not observed these creeks, at or above the "Red Alert" level, to do so.

A few of the creeks I'm talking about include:

Big Stony Creek
Burns Creek
Chimney Rock Fork
Clear Creek
Cove Creek
Devils Fork
Laurel Fork
Little Stony Creek
Machine Creek
Roaring Branch
Straight Fork
Stock Creek
South Fork of the Powell
Guest River Gorge

There are many more creeks.  While most do not have a stream gauge like Big Stony Creek, it can be used as a general guide for the other steep creeks, especially during the cold season.

During summer the possibility of localized downpours in thunderstorms can cause large flow volume differences between adjacent creek basins.

The High Knob Massif is unique in that most major creeks are lake and/or wetland controlled to some extent, with locally significant subterranean conduits retaining much more water.

High Knob Lake holds back water into 
Big Stony Creek of the Clinch River

Big Cherry Lake holds back water 
into South Fork of the Powell River

Bark Camp Lake holds back water into 
Little Stony Creek of the Clinch River

Dual Norton Reservoirs hold back water into 
Benges Branch & City of Norton that feed into 
the Middle Fork of the Powell River

The Glades wetlands slow water going 
into Big Stony Creek and the Clinch River

Appalachia Lake and Keokee Lake along the
Little Stone Mountain-Stone Mountain flank hold back
water entering Middle & North forks of the Powell River

The longest cave system in Virginia, and deepest east of
the Rockies & north of Mexico in North America helps to
hold back and slow run-off until the conduit system fills

*The above being examples, with more ponds-wetlands and
many cave systems that are part of a complex hydrology.

Any area will flood, and certainly that was the case during early March when heavy rain combined with significant loss of snow to generate extensive flooding, rock-mud slides in the area.


March 5, 2015
Clinch River Near Speers Ferry In Scott County
Photograph by Roddy Addington - © All Rights Reserved.

It was a great blessing that deep snow remained and did not all melt away during the early March flooding or it would have been much worse across Wise, Scott, Lee counties.


More than 65 roads were closed in Wise, Scott, Lee, and Dickenson counties during early March.


Flooding of low-lying areas in the East Stone Gap-Big Stone Gap area typically begins when the river stage reaches 5.0 to 6.0 feet, with water around many homes during this early March episode.

March 4, 2015 at 8:27 AM
Run-off From High Knob Massif
Photograph by Cody Blankenbecler - © All Rights Reserved.

The photograph above was taken by Cody near the Flag Rock level, with the scene below at the base of the massif near the City of Norton Water Plant.

March 4, 2015 at 8:32 AM
Run-off From High Knob Massif
Photograph by Cody Blankenbecler - © All Rights Reserved.

The City of Norton rests upon a divide with water shown above flowing into the Powell River while water flowing off the massif east of Benges Branch, and the Norton Reservoir system, goes into the Guest River of the Clinch River.


With exception of January 2015, its been a wet orographic forcing season in the High Knob Massif area with abundant precipitation.

Big Cherry Lake Dam
Orographic Forcing Season
Monthly Precipitation Totals
Observers: Gary Hampton & Staff
Elevation 3120 feet

2014

October: 9.40"

November: 4.02"

December: 5.54"

2015

January: 2.87"

*February: 8.07"

March 1-16: 6.85"

January 1-March 16 Total: 17.79"

October 1-March 16 Total: 36.75"

Average Per Month: 6.66"

*The February 2015 total was mostly based upon 
snow core data and reported snow depths, with bulk 
of precipitation falling as snow above 3000 feet.

March 2015
Looking SW Across Big Cherry Lake Basin
Photograph by Wayne Browning - © All Rights Reserved.

Reference this link for details:
The Harsh Winter Month Of February 2015


Extraordinary Differences
In Southwestern Virginia Precipitation

Although I knew the High Knob Massif area had gotten the most snow in Virginia, as is common, even I was somewhat surprised upon recently catching up with climate data that anomalous dryness had been ruling locations to the east in southwestern and central Virginia.


Highlighting some of these extraordinary precipitation differences across southwestern Virginia ( and the state in general ) is one of the reasons I started this website back in Summer 2009, since most folks ( public & professional ) were not aware of these differences which are climatologically common.

Virginia Drought Monitor For March 3, 2015

There was some flooding in Wise County during February 21-22 with stopped up storm drains and so much snow that water could not run off roads.

Virginia Drought Monitor For February 24, 2015


Specific Site Comparisons

Danville
January 1-March 18: 5.33"
October 1-March 18: 14.85"
( 9.8" of total snowfall for season )

Roanoke
January 1-March 18: 6.41"
October 1-March 18: 16.03"
( 21.7" of total snowfall for season )

Blacksburg
January 1-March 18: 6.55"
October 1-March 18: 16.28"
( 27.8" of total snowfall for season )

Covington Filter Plant
January 1-March 18: 7.35"
October 1-March 18: 16.75"

Wytheville 1 S
January 1-March 18: 6.01"
October 1-March 18: 17.79"
( 20.2" of total snowfall for season )

Bluefield, West Virginia
January 1-March 18: 7.73"
October 1-March 18: 17.95"
( 39.5" of total snowfall for season )

Tri-Cities, Tennessee
January 1-March 18: 8.55"
October 1-March 18: 20.22"
( 15.5" of total snowfall for season )

Saltville 1 N
January 1-March 18: 8.27"
October 1-March 18: 22.16"

Grundy
January 1-March 18: 11.13"
October 1-March 18: 22.36"

Clintwood 1 W
January 1-March 18: 11.64"
October 1-March 18: 22.42"
( 41.6" of total snowfall during season )

Burkes Garden
January 1-March 18: 8.84"
October 1-March 18: 23.46"
( 41.0" of total snowfall during season )

Lebanon
January 1-March 18: 10.72"
October 1-March 18: 25.82"

Big Stone Gap WP
January 1-March 18: 13.62"
October 1-March 18: 31.69"

Appalachia Lake WP
January 1-March 18: 14.75"
October 1-March 18: 31.70"

City of Norton WP
January 1-March 18: 15.33"
October 1-March 18: 32.56"
( Around 60.0" of total snowfall for season )

Big Cherry Dam
January 1-March 18: 17.79"
October 1-March 18: 36.75"
( 120.0" of total snowfall in head of basin )

*Big Cherry Dam has missing data due to evaporation between hand-measurements which average 1 per week, and losses due to winter snowfall ( the February total being based upon snow core data ).

This section is under construction.  Please check back.

Monday, February 23, 2015

The Harsh Winter Month Of February 2015


( 8" More Fell After This Photograph )
Snow Depth At 1:35 PM on February 21, 2015
Mean Depth In High Chaparral of High Knob Massif
Photograph by Darlene Fields - © All Rights Reserved.

The mean snow depth reached 36" in High Chaparral during evening hours of February 21, with up to 40"+ on northern slopes in the main crest zone of the High Knob Massif.

The High Knob Landform

The High Knob Landform WebCite Permalink

The Appalachian Climate Center

Following a snowy opening to Winter 2014-15, during the month of November, a snow drought developed across the southern Appalachians with much below average snowfall observed during the typically snowy months of December & January.

First Significant Winter Storm of 2014-15 Season

That all began to change during February.

February 16, 2015 At 5:06 PM
 Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

February 17, 2015 At 6:06 PM
 Looking Toward High Knob Massif
University Of Virginia's College At Wise
Courtesy Of Computer Science-Mathematics Department

February 18, 2015
Deep Roof-top Snow Depths
Snow Accumulation In The Lower Elevations
Photograph by Wayne Browning - © All Rights Reserved.

A total of 19.3" of snowfall was officially measured in Clintwood during the February 12-19 period, with mean snow depths of 12" to 14" being common amid the lower elevations by February 16-19.

A series of snow systems during February 12-19 resulted in the first major storm that dropped deep snow upon the entire area along and northwest of the Clinch River in southwestern Virginia, with widespread 10-18" snow depths by February 17.

February 18, 2015 at 2:56 PM
High Knob Massif At 3300 feet Elevation
Snow Depth In High Chaparral Community
Photograph by Darlene Fields - © All Rights Reserved.

A general 24-30" of total snow fell upon upper elevations of the High Knob Massif during the February 12-19 period, with general 1-2 feet snow depths by February 18 above 3000 feet ( least on southern slopes and most on northern slopes ).

February 18, 2015
Snow Burst Along Alternate 58
Bad Travel Conditions Between Norton & Coeburn
Photograph by Darlene Fields - © All Rights Reserved.

A deep snowpack and fresh mass of arctic air set the stage for the coldest still air temperatures since February 1996, with the bottom literally dropping out of the thermometer into morning hours of February 20 amid mountain valleys.

A Few MINS On February 20

-23 degrees in Clintwood
( Official NWS Temperature )

-22 degrees in Clinch River Valley
( Mark & Ana Hess Farm )

-21 degrees in City of Norton
( AWS Weatherbug Station )

-20 degrees in Tazewell
( AWS Weatherbug Station )

-19 degrees in Birchleaf
( AWS Weatherbug Station )

*Local minimums amid lofty 2400 to 3500 foot high valleys in the
High Knob Massif likely reached -25 to -30 degrees below zero,
or even colder, with 1-2 feet of surrounding snowpack.


High Impact Winter Storm of February 21
SW Upslope Driven Storm Event
Excessive Snowfall In High Knob Landform

Although there was some S-SSE flow in lowest levels, ROARING SSW-SW winds dominated from around 900 MB upward to drive this event and generate upslope cooling as air was orographically forced to rise from the Tennessee Valley upward through the High Knob Landform into the great, sprawling High Knob Massif and Tennessee Valley Divide ( which includes the Black mountains ).

February 21, 2015 At 7:00 AM
European 16 KM Model 850 MB Wind Field

February 21, 2015 At 7:00 PM
European 16 KM Model 850 MB Wind Field

While I have documented SW Upslope Flow snow events many times in past decades, my analog storm for this event occurred on November 27, 1977 when an early season blast of arctic air was flooded by Gulf of Mexico moisture on strong SW flow in a manner analogous to this event.  Snow depths reached 18" in Big Stone Gap and 11" in Wise during 1977.

21" of Mean Snow Depth
7" of New Snow ( 15" To Come )
February 21, 2015 At 8:54 AM
Heavy Snow In High Chaparral
Photograph by Darlene Fields - © All Rights Reserved.

Roaring SW winds of 30 to 50+ mph created blizzard conditions in the High Knob Massif 
where this storm became a beast.

A general 1 to 2 feet of snow was already on the ground before February 21, with deepest snow across northern slopes in the upper elevations.  High Chaparral has a southern exposure.

Mean Snow Depth Change
High Chaparral of High Knob Massif
Elevation 3300 feet

14" at 7:00 PM 
( February 20 )

21" at 8:54 AM
( February 21 )

31" at 4:00 PM
( February 21 )

36" at 10:30 PM
( February 21 )

Mean snow depths topped 40" on northern slopes in the upper elevations of the massif, with simply huge drifts in places.

The snow depth change was documented on Eagle Knob 
by Cody Blankenbecler, with much snow being blown horizontally across the summit prior to this event 
during the February 12-19 period.

Elevation 4196 feet
February 21, 2015 At 1:23 AM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

Elevation 4196 feet
February 21, 2015 At 3:01 AM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

Elevation 4196 feet
February 21, 2015 At 11:10 AM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

Elevation 4196 feet
February 21, 2015 At 9:05 PM
Eagle Knob of High Knob Massif
Image by Cody Blankenbecler - © All Rights Reserved.

*Snow depth in the above view is around waist deep.

Total snow depth was ( as it typically is ) much deeper on northern slopes in adjacent basins holding High Knob Lake, Big Cherry Lake, and the Norton Reservoirs where not only is more deposited but less snow tends to melt-sublimate due to less insolation ( i.e., shady & colder with less sunlight ).

Cal Adams reported waist deep snow at his home just across the Scott County, Va., line adjacent to Big Cherry Lake. Cal was stranded, deep in the high-country, like he had been many times in the 12-years since moving to Little Mountain.

While having plenty of food, Cal was running short on milk & bread.  He said it would be nice to have some "sweet milk and a loaf of bread" air dropped in, or flown by military drone if anyone had the means to do the job!

What he really needed, however, was a Dozer to push through HUGE drifts that blocked Route 238.

*The Scott County Police Department called to check on him, which was very nice, but he asked that folks "please don't forget about me."

Updated: Cal was rescued by two Virginia Department of Forestry Dozers which worked to open State Route 619 and Route 237.  Cal said, "I want to thank them for saving my life," as he was running out of his medications.  He truly was thankful to the VA Department of Forestry!

*Following 6" of new snow into the morning of February 26 Cal said, "I've got 4 FEET of snow on my porch!"

Many private and secondary roads have remained bad to impassible since the February 21 storm, with Joe & Darlene Fields being unable to get out of Lark Road due to 3 feet & more of snow depth.

February 24, 2015 At 12:19 PM
Mountains of Snow Piled High In High Chaparral
Not Boston But High Chaparral of High Knob
Photograph by Darlene Fields - © All Rights Reserved.

Huge piles of snow have High Chaparral looking like Boston, and little wonder after nearly 5 feet of snow has fallen just during the month of February 
( around 6 feet at the summit level as of Feb 26 ).

It has become the snowiest February on record in upper elevations of the High Knob Massif, where more than 70" 
have fallen around the summit level during the month.

Once State Route 619 and Route 237 were opened by Virginia Department of Forestry Dozers, snow depth along these roads, amid upper elevations, was reported to be near level with the door handle to lower section of windows, on the driver and passenger sides, of standard 4X4 vehicles.

This was reported by numerous individuals and verified the already documented 40" to 50" snow depths across northern exposed slopes ( 30" to 40" on southern exposed slopes ).  Cal Adams said it was certainly true at his home, with "snow depth up to the door handle on my truck."

February 21, 2015 At 1:35 PM
Before 8" Of Additional Snow Depth
View Of 28" From The Doorway
Photograph by Darlene Fields - © All Rights Reserved.

Cold air that followed all this snow froze it into a SOLID Block hard enough for many to walk on top of, which helped in getting from A to B but made it even harder if you needed to move it out OF the way.  Yes, it is true, rock bars & chisels have been used to help move this snow! 

February 24, 2015
High Chaparral of High Knob Massif
Mounds Of Snow Frozen Solid Like A Block
Photograph by Darlene Fields - © All Rights Reserved.

While it might look like Joe is just out in his yard measuring a little snow, he is actually doing that while standing on top of more than 2 feet of snow!

February 24, 2015
Joe Fields Measures New Snow
High Chaparral of High Knob Massif
Standing On Top Of More Than 2 Feet
Photograph by Darlene Fields - © All Rights Reserved.

Even in lower elevations, upstream of the High Knob Massif, this period was difficult with many added complications due to frozen water lines, blocked roads, and VDOT generated "avalanches" like observed along my road that runs parallel to the state road for several hundred feet.

*The driveway was buried by 2-3 feet or more of snow as
all the snow from the state road was plowed over the bank!

February 2015
VDOT Generated Avalanche
Several Hundred Feet of Driveway Buried
Photograph by Wayne Browning - © All Rights Reserved.

Don't get me wrong, we are all appreciative of the long, hard hours that VDOT puts in during such extended periods of severe weather.

February 2015
VDOT Plowing Snow In Wise County, Virginia
Photograph by Roddy Addington - © All Rights Reserved.

One of the most dangerous and damaging aspects of this harsh February of record snowfall was build up of snow loads, which reached critical values in many places with dozens of collapsed structures in counties along the mountainous Virginia-Kentucky stateline ( Wise County being among the hardest hit ).

February 2015 in Wise County, Virginia
Morgan-McClure In The Town of Coeburn
Classic Cars Destroyed By Building Collapse 
Photograph by Roddy Addington - © All Rights Reserved.

My friend & photographer Roddy Addington captured one of the most expensive losses as a building containing classic cars in the Town of Coeburn collapsed under the heavy snow load 
( water weight ).

February 2015 in Wise County, Virginia
Morgan-McClure In The Town of Coeburn
Classic Cars Destroyed By Building Collapse 
Photograph by Roddy Addington - © All Rights Reserved.

While a building collapse on classic cars made TV news, the dozens and dozens of other structures which collapsed were just as important to those impacted by the damage.

February 2015 in Wise County, Virginia
Morgan-McClure In The Town of Coeburn
Classic Cars Destroyed By Building Collapse 
Photograph by Roddy Addington - © All Rights Reserved.

These collapses occurred across the area.

February 2015
Collapse From Snow Load Weight
Private Home Damage In Wise County, Virginia
Photograph by Roddy Addington - © All Rights Reserved.

Many private and commercial structures 
were impacted.

February 2015
Town of Wise, Virginia
Damage From Snow Load In Downtown Wise
Photograph by Roddy Addington - © All Rights Reserved.

The best photograph Rod took during this event was of a kid shoveling snow, with the expression on this child's face saying it all about record snowfall in February 2015!

February 2015
Wise County, Virginia
Kid's Face Says It All About Record Snow
Photograph by Roddy Addington - © All Rights Reserved.

There can always be too much of anything!

February 2015
Car Buried By Snow In Wise County, Virginia
Photograph by Roddy Addington - © All Rights Reserved.

The final snowfall numbers were significant.

February 2015 Snowfall Totals

Dungannon In Clinch River Valley: 26.4"

Clintwood 1 W: 30.4"

Big Stone Gap WWTP: 32.0"

Norton Water Plant: 40.0"

Wise 3 E: 41.7"

High Chaparral of High Knob Massif: 56.0"

Crest Zone of High Knob Massif: 73.0"

Water equivalent precipitation totals were significant amid the lifting zone of the High Knob Massif with 6.33" at the City of Norton Water Plant and 6.23" at Appalachia Lake Water Plant, along northern bases of the massif, and approximately 8.07" at Big Cherry Dam in the high country.

*Great orographic enhancement occurred with SW upslope flow when nearly all snow fell above 3000 feet in the High Knob Massif area during February 20-21 ( 20" to 30" of new snowfall ).

Reference My Appalachian Climate Center 
for more specific climate details.

High Knob Massif - March 9, 2015
Looking SW Across Big Cherry Lake Basin
Photograph by Wayne Browning - © All Rights Reserved.

*The 8.07" being based upon snow core data and reported snow depths, as well as partial rain gauge catches which could not begin to hold all the deep snow ( 5-6 feet ).

The general 40-50" on northern exposed slopes 
( NW-N-NE ), 30-40" on southern exposed slopes, were the greatest snow depths reported across the southern Appalachians during February 2015.

February 22, 2015
Powell River of Upper Tennessee Basin
Cumberland Mountain of High Knob Landform
Winter Panorama In Wilderness Road State Park
Photograph by Harold L. Jerrell - © All Rights Reserved.

Despite the harsh nature of February 2015, there was simply no denying the great beauty that also came with record snowfall in the Cumberlands.

Lee County, Virginia
February 24, 2015 at 5:27 PM
White Rocks of Cumberland Mountain
Deep Snow In Valley Beneath The White Rocks
Photograph by Harold L. Jerrell - © All Rights Reserved.

Certainly a February that 
will not be soon forgotten.

Lee County, Virginia
February 21, 2015 at 12:41 PM
New Snow On Car In Silver Leaf Community
Photograph by Harold L. Jerrell - © All Rights Reserved.