Monday, February 4, 2013

Cold & Snowy Opening To February 2013


February 3, 2013
Powell River Valley of Upper Tennessee River Basin
Snow Falling Upon Silver Leaf of Western Lee County
Photograph by Harold L. Jerrell - © All Rights Reserved.

A series of upper air disturbances rotating around a Polar Vortex over southeastern Canada, generally known as "Clippers," generated a cold and snowy opening to February 2013 along the Appalachians.

January 18, 2013 At 1200 UTC
ECMWF 500 MB Analysis - Northern Hemisphere

Observe the Polar Vortex over southeastern Canada has been essentially in the same position for several weeks; although, sensible weather conditions have varied radically during that time across the southern Appalachians it has been COLD in the mean.

February 4, 2013 At 1200 UTC
ECMWF 500 MB Analysis - Northern Hemisphere

Mean Temperatures ( 18-Day ) 
January 18-February 4, 2013

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 35.6 degrees
Average Daily MIN: 16.0 degrees
18-Day MEAN: 25.8 degrees
MAX Temperature: 63 degrees
MIN Temperature: 6 degrees

Local cooling was in part enhanced by deep snow deposited during The Fast & Furious Storm of January 17, with 1" or more of snow depth on the ground for much of this 18 day period ( * ).


*The entire 18-day period featured 1" or more of snow depth
on upper north slopes in the High Knob Massif
( e.g., in High Knob Lake Basin ).

February 3, 2013
Wilderness Road State Park - East Cabin
Photograph by Harold L. Jerrell - © All Rights Reserved.

The coldest 4 days of the 2012-13 
winter season opened February

Mean Temperatures 
February 1-4, 2013

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 30.2 degrees
Average Daily MIN: 11.5 degrees
4-Day MEAN: 20.8 degrees

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 25.9 degrees
Average Daily MIN: 7.8 degrees
4-Day MEAN: 16.8 degrees

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 25.7 degrees
Average Daily MIN: 10.8 degrees
4-Day MEAN: 18.2 degrees

February 3, 2013
Blacksmith Shop - Wilderness Road State Park
Photograph by Harold L. Jerrell - © All Rights Reserved.



Arctic Blast & Clippers
Waves of Snow During 4-Days
( January 31-February 3, 2013 )

High Knob Massif
Elevation 3300 feet
AM Snow Depth In High Chaparral - January 31
Photograph by Darlene Fields - © All Rights Reserved.

A transition to snow at the end of a major rain and high water event ended January 2013 with 2" to 3" of snow depth above 3000 feet in the High Knob Massif into morning hours of January 31.

January 31, 2013 at 1:31 PM
University of Virginia's College In Wise

Accumulations were much less at lower elevations into January 31, with generally 0.5" or less below 3000 feet in locations north of the High Knob Massif ( from Norton-Wise to Clintwood ).

Arctic Cold Front
February 1, 2013 at 2:17 AM
University of Virginia's College In Wise

Conditions turned BAD between midnight and sunrise on February 1 as heavy snow, blowing snow in strong winds, and plunging temperatures with stinging wind chills combined to generate a high impact upon roadways and anything outside!

Bitter Cold Day
February 1, 2013 at 12:59 PM
University of Virginia's College In Wise

Despite the return of sunshine, afternoon maxs reached only the 10s from Norton-Wise and Long Ridge upward in elevation over a general 2" to 4" 
of new snow that coated the mountain landscape from the High Knob Massif north to Clintwood and Pine Mountain on the Virginia-Kentucky border.

February 2, 2013
Long Ridge of the Tennessee Valley Divide
Awesome Sun Pillar Greets Dawn On February 2
Photograph by Wayne Riner - © All Rights Reserved.

Following sub-zero to single digit MINS, above 2000 feet, temperatures were already rising before sunrise on February 2 as gusty winds across higher mountain ridges foreshadowed the arrival of an Alberta Clipper fall of snow.

Gusty S-SW winds offsetting the temperature rise
to generate sub-zero to single digit wind chill factors.

Morning of February 2, 2013
Sun Pillar Before A New Snowfall
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Photograph Thoughts...
"The vertical shaft of light is caused by ice crystals in the atmosphere. Not long after this sunrise, snow started to fall."

February 2, 2013
Majesty of Sun Pillar Above The Highlands
Photograph by Wayne Riner - © All Rights Reserved.

Snow fell briskly February 2, with SW-WSW air flow trajectories allowing best accumulations to occur from the High Knob Landform south 
into the Great Valley of northeast Tennessee.

Climatology shows that best snowfall amounts, relative to other locations, occur at TRI ( Tri-Cities ) when air flow trajectories are UP-Valley ( SW-WSW ) to minimize downsloping ( i.e., warming & moisture extraction ).

Elevation 3300 feet
February 2, 2013 at 4:18 PM
Darlene Fields Measuring Snowfall In High Chaparral
Photograph by Darlene Fields - © All Rights Reserved.

Snow depth from the February 1-2 period topped 5" in High Chaparral of the High Knob Massif by late afternoon on February 2, to push the event total to 8.0" ( when including 2.5" of January 31 ).

High Knob Massif
February 3, 2013 at 12:04 PM
Darlene Fields Measuring Snowfall In High Chaparral
Photograph by Darlene Fields - © All Rights Reserved.

Another clipper brought an additional round of moderate to heavy snow into February 3, with 3" of new snow depth accumulating in High Chaparral to make 11.0" of total fall for the event up to this point ( 1.0" of new fell by 5 PM ).


Snowfall Event Totals
( January 31-February 3, 2013 )

Clintwood 1 W: 6.6"

Nora 4 SSE: 6.9"

City of Norton Water Plant: 9.0"

High Chaparral of High Knob Massif: 12.0"

Locally up to around 16.0" of snow fell amid the main crest zone of the massif, west-southwest of High Chaparral, with highly variable depths due to strong winds and blowing-drifting in exposed locations above 3000 feet.

Snow depths of 8" to 12" were common above 3000 feet in the massif, outside of drifts, with settlement over time on the snowpack into February 3.



Climate Statistics
For January 2013

Majestic Cowan Mill of The Powell River Valley
Photograph by Harold L. Jerrell - © All Rights Reserved.

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 44.2 degrees
Average Daily MIN: 25.0 degrees
MEAN: 34.6 degrees
Highest Temperature: 69 degrees
Lowest Temperature: 10 degrees
Total Precipitation: 6.81"
Total Snowfall: 7.2"

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 41.8 degrees
Average Daily MIN: 23.3 degrees
MEAN: 32.6 degrees
Highest Temperature: 66 degrees
Lowest Temperature: 9 degrees
Total Precipitation: 9.37"
Total Snowfall: 11.0"

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 41.2 degrees
Average Daily MIN: 26.5 degrees
MEAN: 33.8 degrees
Highest Temperature: 65 degrees
Lowest Temperature: 8 degrees
Total Precipitation: 7.73"
Total Snowfall: 12.0"

In the High Knob Massif mean January temps varied from 30s to around 40 degrees above 2700 feet by day into the 20-25 degree range by night.  Above average.

January was wet with a general 10.00" to 12.00" 
of total precip across the massif area, to include 
15-20" of snowfall above 2000-3000 feet 
( below average snowfall ).

A total of 24 out of 31 January days had 1" or more of snow depth across northern slopes of High Knob Lake Basin.  Snow cover was patchy to continuous from December 21 to January 12 and from January 17 to present ( February 6 ).

Majesty Of Winter In The High Knob Massif

The Fast & Furious Storm of January 2013

Due to Superstorm Sandy, snow cover had previously been continuous to patchy from October 28 to November 21.

Historic Winter Storm of October 2012

A total of 8 weeks of snow cover have been observed
for the 2012-13 winter season through February 6
( snow cover = 1" or more of depth ).

February 3, 2013
Martin's Station At Wilderness Road State Park
Photograph by Harold L. Jerrell - © All Rights Reserved.



Wetness of January 2013

Cumberland Gap National Historical Park
Whitewater Flowing In Abundance To Begin 2013
Photograph by Harold L. Jerrell - © All Rights Reserved.

The bounty of precipitation during January 2013 had whitewater gushing out of the sprawling High Knob Massif on many days, with Watersheds Films capturing a run during The Fast & Furious Storm of January 17 when reportedly an amazing 15" of snow fell upon the Gorge area in 3 hours 
( reference Youtube footnotes ).

Other reports of around 15" of snow depth came from this section which extended east into the St. Paul - Castlewood area and north into Sandy Ridge ( reference The Fast & Furious link above ).

During The Fast & Furious Snowstorm
One For The Books - Little Stony Gorge Run

January 17, 2013
Little Stony Gorge of High Knob Massif
One For The Books - Little Stony Creek Whitewater
Video By Watersheds Films

Watch In Full Screen Mode 
For Best Viewing.

Little Stony Creek drains 16.43 square miles ( 10, 515 acres ) of the High Knob Massif into the ecologically renowned Clinch River of the Upper Tennessee River Basin.

Little Stony Gorge of Clinch River

Big Stony Creek drains 41.87 square miles ( 26, 797 acres ) of the High Knob Massif area into the Clinch River along a 13 mile course downstream of High Knob Lake.  The Big Stony Creek Basin is west of the Little Stony ( and should not be confused with it ).

Two major precipitation events pushed the Clinch River, into which Little Stony Creek drains, above flood stage twice during January 2013.

Downstream of High Knob Massif
Clinch River At Speers Ferry In Scott County, VA

The final event during January 30-31 had the greatest impact upon the Powell River sections of the massif, with both the South Fork draining Big Cherry Basin and Powell Valley in Wise County and the mainstem Powell River near Jonesville rising higher than during the mid-January episode.

South Fork of Powell River drains 40 square miles ( 25,600 acres ) of the High Knob Massif area into the Powell River along a 17+ mile course from its headwaters [ flows 6.1 miles through wetland valleys, above Big Cherry Lake, at around 3200 feet above sea level ( around 10 miles above 3000 feet )].

South Fork Gorge of Powell River

Near Confluence of South Fork of The Powell
Powell River At Big Stone Gap In Wise County, VA

Powell River Near Jonesville In Lee County, VA

While January 2013 was the wettest in recent memory, it was not the wettest January on record with the great flood months of January 1957 and January 1937 standing out with amounts that soared into double digits as well.

Reported Precipitation Totals
January 1937

CCC Camp No.5 in Lee County
13.61"

Rose Hill
13.21"

**Eagle Knob of High Knob Massif
12.15"

Dunbar In Wise County
11.85"

Jonesville
11.38"

Olinger
11.13"

**From an automated TVA tipping-bucket rain gauge.  Total likely low due to strong winds and sub-freezing temperatures
( and frozen precipitation ) at 4000+ feet elevation.

February 3, 2013
Gap Creek Flowing From The Gap Cave System
Photograph by Harold L. Jerrell - © All Rights Reserved.

Gap Creek is one of many natural wonders of the High Knob Landform and great Cumberland Gap National Historical Park, with the creek flowing out of the 17.1 mile long Gap Cave System.

Cumberland Gap National Historical Park
Whitewater of Gap Creek In February 2013
Photograph by Harold L. Jerrell - © All Rights Reserved.


Composite Charts Of Pattern Contrasts

500 MB Height Anomaly - January 2013

While January 2013 was warmer than average, the monthly 500 MB height composite anomaly is a bit deceptive in that the month featured two distinct regimes ( mild & wet verses wintry ).

Mild & Wet S-SW Flow Dominated
500 MB Height Anomaly for January 1-17

More Wintry WNW Flow Dominated
500 MB Height Anomaly for January 18-31

As previously noted, the persistent Polar Vortex over southeastern Canada acted to drive the pattern in recent weeks and shows up well on composite anomaly charts for the Northern Hemisphere.

WNW-NW Flow Dominated
500 MB Height Anomaly for January 18-February 3

These two contrasting regimes show up well on composite 850 MB air temperature anomaly charts.

850 MB Air Temperature Anomaly for January 1-17

850 MB Air Temp Anomaly for January 18-February 3

And on 850 MB wind vector anomaly composites.

January 1-17
850 MB Wind Vector Anomaly

A radical change in mean wind directions.

January 18 to February 3
850 MB Wind Vector Anomaly


Winter Birds

Red-bellied Woodpecker ( Melanerpes carolinus )
Photograph by Harold L. Jerrell - © All Rights Reserved.

The Red-bellied is one of my favorite woodpeckers to watch and listen to throughout the year.

Red-breasted Nuthatch ( Sitta canadensis )
Photograph by Harold L. Jerrell - © All Rights Reserved.

Nuthatches are wondrous little rascals.  They are always a treat, with the Red-breasted occasionally being seen and heard in the High Knob Massif during the spring-summer.

White-throated Sparrow ( Zonotrichia albicollis )
Photograph by Harold L. Jerrell - © All Rights Reserved.

Glorious songsters.  White-throated Sparrows brighten up even the darkest, coldest winter days!

FLUFFED For The Cold Season
American Goldfinch ( Carduelis tristis )
Photograph by Harold L. Jerrell - © All Rights Reserved.

Goldfinches brighten in color as 
"true" spring arrives.

A Perspective In Spacing
Altocumulus Majesty At Sunset
Photograph by Harold L. Jerrell - © All Rights Reserved.

Gorgeous sunsets above the Powell River Valley.

Variety In Cloud Types & Bases
Colorful Contrasts At Sunset
Photograph by Harold L. Jerrell - © All Rights Reserved.

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