Tuesday, October 5, 2010

September 2010: Fall Opens Drier & Warmer


High Knob Massif
Jefferson National Forest
Bark Camp Lake - Elevation 2734 feet - September 26
Photograph by Roddy Addington - © All Rights Reserved.

The High Knob Landform

Late September brought beautiful color changes to the High Knob Massif, with photographer Roddy Addington capturing the majestic setting of Bark Camp Lake in Little Stony Basin of the Clinch River on September 26 ( northern Scott County, Virginia ).

Brightening colorations of early autumn were also observed in upper reaches of South Fork of the Powell River Basin, just over
9 air miles across the highcountry from Bark Camp Lake in Wise County, Va., on September 23.  Vivid colors decorated jagged cliffs above the 3000 foot level in South Fork Gorge, and were emerging amid the cold air drainages of Big Cherry Basin.

Misty Fog In Brighter Light
Majestic Bark Camp Lake of Little Stony Basin
Photograph by Roddy Addington - © All Rights Reserved.

Nice September color emerging despite the warmer than average conditions, as unseasonably warm days were not quite balanced out by morning coolness.

September 26, 2010
Changing Light & Steam Fog Above Bark Camp Lake
 Photograph by Roddy Addington - © All Rights Reserved.

Steam fog is the most localized form of condensed water vapor, created as cool air passes across the warmer water surface of Bark Camp Lake, and is a common feature throughout the year within the cold air drainage basin lakes of the High Knob Massif.  During the cold season, prior to lake freeze up, the formation of steam fog can generate thick hoar frost on trees and vegetation along the lake.  It is part of a interesting and very important array of secondary moisture sources which collectively add greatly to the annual water budget of this already high precipitation area.

Bark Camp Lake Recreation Area
Ripples In Sky Are Reflected On Lake Surface
Photograph by Roddy Addington - © All Rights Reserved.

The coldest mornings of September occurred early in the month, with 30s to around 40 degrees in colder basins amid early hours of September 5-6 ( perhaps with a kiss of frost in coldest locales ).

Jefferson National Forest
Little Stony Gorge of High Knob Massif
Bear Rock Overlook - September 26, 2010
Photograph by Roddy Addington - © All Rights Reserved.

Miles downstream from lovely Bark Camp Lake, the rushing whitewater rapids of Little Stony Creek of the Clinch River drain this diverse 16.4 square mile basin through jagged rock outcrops of Little Stony Gorge ( a portion of the American Whitewater rated Class IV-V+ gorge being viewed from Bear Rock above ).

[ Reference the following section of my website to view whitewater action in Little Stony Gorge during September 2009:



Climate Statistics 
For September 2010

September 26, 2010
Little Stony Basin of High Knob Massif
Scarlet Oak ( Quercus coccinea ) and Gilled Fungi
Photograph by Roddy Addington - © All Rights Reserved.

The arrival of September in the High Knob Landform means that colors are not only emerging above, but also richly upon the forest floor!

Reference the following section of my website to see colorations during September 2009:


September 2010 generated above average temps and below average rainfall across the mountain landscape, including nearly all of the High Knob Landform ( near to above average September rainfall was observed across Cumberland Gap National Historical Park ).

Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 78.9 degrees
Average Daily MIN: 51.0 degrees
MEAN: 65.0 degrees
Highest Temperature: 88 degrees
Lowest Temperature: 43 degrees
September Rainfall: 2.17"
2010 Precipitation: 34.14"

( Long Ridge of Sandy Ridge )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 77.1 degrees
Average Daily MIN: 58.7 degrees
MEAN: 67.9 degrees
Highest Temperature: 87 degrees
Lowest Temperature: 48 degrees
September Rainfall: 2.07"
2010 Precipitation: 36.49"

City of Norton - Elevation 2141 feet
Average Daily MAX: 77.5 degrees
Average Daily MIN: 48.6 degrees
MEAN: 63.0 degrees
Highest Temperature: 88 degrees
Lowest Temperature: 40 degrees
September Rainfall: 3.58"
2010 Precipitation: 42.71"

In the High Knob highcountry September temp means varied from mid 60s to lower 70s by day to mid-upper 40s by night within the colder mountain basins ( exposed ridges had average mins in the low-mid 50s ). 

Rainfall was well below long-term averages with September totals varying from 2.83" at Appalachia Lake Water Plant, upon the Little Stone Mountain arm of the massif, to 3.75" on Eagle Knob of High Knob near the heads of Benges Basin, Clear Creek Basin, Big Cherry Basin & High Knob Lake Basin.

September 26, 2010
Little Stony Basin of High Knob Massif
Colorful Mushrooms Growing Out Of Stump
Photograph by Roddy Addington - © All Rights Reserved.

My friends Otis & Nancy Ward measured 3.52" of rainfall in the Robinson Knob community of the massif, near the head of Little Stony Basin, during September.

While below average, a very wet August provided plenty of moisture for an abundant array of fungi 
( 12.34" of August + September rain fell in Robinson Knob ).

September 2010 was the driest in 2 years at 
Big Cherry Dam, with my friend Gary Hampton measuring only 2.88" of rainfall ( actual tally was likely over 3.00" due to evaporation from the rain gauge, however, it was still the driest month since the autumn of 2008 ).


Regional Climate Statistics
For September 2010

Jackson, Ky., NWSFO - Elevation 1365 feet
Average Daily MAX: 81.2 degrees
Average Daily MIN: 59.9 degrees
MEAN: 70.4 degrees
Highest Temperature: 92 degrees
Lowest Temperature: 50 degrees
September Rainfall: 2.05"
2010 Precipitation: 34.84"

London, Kentucky - Elevation 1211 feet
Average Daily MAX: 80.8 degrees
Average Daily MIN: 56.2 degrees
MEAN: 68.5 degrees
Highest Temperature: 90 degrees
Lowest Temperature: 46 degrees
September Rainfall: 2.78"
2010 Precipitation: 35.52"

Buckhorn Lake State Park, Ky., - Elevation 780 feet
Average Daily MAX: 83.7 degrees
Average Daily MIN: 56.6 degrees
MEAN: 70.2 degrees
Highest Temperature: 93 degrees
Lowest Temperature: 50 degrees
September Rainfall: 2.52"
2010 Precipitation: 35.85"
( 1 day missing in September )

Tri-Cities, Tennessee - Elevation 1525 feet
Average Daily MAX: 81.6 degrees
Average Daily MIN: 56.8 degrees
MEAN: 69.2 degrees
Highest Temperature: 92 degrees
Lowest Temperature: 47 degrees
September Rainfall: 4.04"
2010 Precipitation: 27.54"

Knoxville, Tennessee - Elevation 981 feet
Average Daily MAX: 84.6 degrees
Average Daily MIN: 61.7 degrees
MEAN: 73.2 degrees
Highest Temperature: 94 degrees
Lowest Temperature: 50 degrees
September Rainfall: 4.34"
2010 Precipitation: 32.88"

Chattanooga, Tennessee - Elevation 683 feet
Average Daily MAX: 89.6 degrees
Average Daily MIN: 64.0 degrees
MEAN: 76.8 degrees
Highest Temperature: 98 degrees
Lowest Temperature: 53 degrees
September Rainfall: 1.13"
2010 Precipitation: 30.17" ( -11.52" )

Richmond, Va., ( State Capitol ) - Elevation 167 feet
Average Daily MAX: 86.6 degrees
Average Daily MIN: 62.5 degrees
MEAN: 74.6 degrees
Highest Temperature: 97 degrees
Lowest Temperature: 53 degrees
September Rainfall: 6.49"
2010 Precipitation: 29.22"
 
September 26, 2010
Little Stony Basin of High Knob Massif
Fungi Heaven In Southern Appalachians
Photograph by Roddy Addington - © All Rights Reserved.

A very interesting weather trend was observed during September, with above average rains across much of the Great Valley of eastern Tennessee 
( except the far south ), and east of the Appalachians in Virginia and North Carolina, being opposite of conditions which ruled Summer 2010.

[ The shift away from summer wetness along the western slopes of the Appalachians being due largely to tropical cyclone tracks, and in the bigger picture to formation of La Nina conditions across the equatorial Pacific Ocean ( which tends to locally favor early-mid Autumn dryness ) ].

September 29, 2010
Russell Fork Basin of Big Sandy River
Rippling Morning Fog Layer From Long Ridge
 Photograph by Wayne Riner - © All Rights Reserved.

[ Looking toward the northeastern end of Pine Mountain, where it plunges into Breaks Gorge, photographer Wayne Riner captured a gorgeous morning inversion with rippling waves of fog obscuring all but the highest ridges ].


A Few Selected Regional
Precipitation Points

Virginia & District of Columbia

[ Note:  All the National Weather Service Cooperative data listed below is to be considered preliminary until its officially certified by the National Climatic Data Center ( NCDC ).  Errors may exist.  Chosen data points are only for the general illustration of regional precipitation variations. ].

Woodstock 2 NE
September Rainfall: 2.76"
August-September Rain: 4.12"
2010 Precipitation: 20.46"
( 1 day missing in July )

Dale Enterprise
September Rainfall: 2.27"
August-September Rain: 4.58"
2010 Precipitation: 20.77"

Washington D.C. - National Airport
September Rainfall: 6.02"
August-September Rain: 8.61"
2010 Precipitation: 27.38"

Charlottesville
September Rainfall: 5.49"
August-September Rain: 7.85"
2010 Precipitation: 27.94"

Richmond
September Rainfall: 6.49"
August-September Rain: 10.41"
2010 Precipitation: 29.22"

Bland
September Rainfall: 2.82"
August-September Rain: 7.44"
2010 Precipitation: 30.58"
( 1 day missing in June / 2 days in August )

Blacksburg
September Rainfall: 3.59"
August-September Rain: 8.68"
2010 Precipitation: 31.40"

Wytheville 1 S
September Rainfall: 3.37"
August-September Rain: 9.70"
2010 Precipitation: 31.48"

Lebanon
September Rainfall: 1.91"
August-September Rain: 8.76"
2010 Precipitation: 33.45"

Clintwood
September Rainfall: 2.17"
August-September Rain: 5.90"
2010 Precipitation: 34.14"

Richlands
September Rainfall: 2.56"
August-September Rain: 8.42"
2010 Precipitation: 35.27"

Wise RAWS
( U.S. Forest Service )
September Rainfall: 2.41"
August-September Rain: 8.43"
2010 Precipitation: 36.06"

Breaks Interstate Park
September Rainfall: 2.85"
August-September Rain: 4.50"
2010 Precipitation: 36.27"

Nora 4 SSE
September Rainfall: 2.07"
August-September Rain: 8.02"
2010 Precipitation: 36.49"

Burkes Garden
September Rainfall: 2.09"
August-September Rain: 8.56"
2010 Precipitation: 38.07"

Saltville 1 N
September Rainfall: 3.25"
August-September Rain: 10.70"
2010 Precipitation: 38.11"
( 2 days missing June / 3 days August )

Pennington Gap
September Rainfall: 3.08"
August-September Rain: 9.05"
2010 Precipitation: 39.58"
( 6 days missing during year )

Appalachia Lake Water Plant
September Rainfall: 2.83"
August-September Rain: 9.49"
2010 Precipitation: 41.02"

Norton Water Plant
September Rainfall: 3.58"
August-September Rain: 11.23"
2010 Precipitation: 42.71"

Robinson Knob of High Knob Massif
September Rainfall: 3.52"
August-September Rain: 12.34"
2010 Precipitation: 43.47" ( M )

Big Stone Gap Water Plant
( South Fork Gorge of High Knob Massif )
September Rainfall: 3.34"
August-September Rain: 12.91"
2010 Precipitation: 43.56"

Stuart
September Rainfall: 6.12"
August-September Rain: 16.36"
2010 Precipitation: 46.11"
( 6 days missing July + August )

Meadows of Dan 5 SW
September Rainfall: 6.73"
August-September Rain: 14.42"
2010 Precipitation: 46.71"
( 6 days missing in July )

Big Cherry Dam of High Knob Massif
September Rainfall: 2.88"
August-September Rain: 11.79"
*2010 Precipitation: 51.36" ( M )

August-September rainfall amounts of 12"-18"+ were common along the High Knob Massif, from extreme southern Wise County across northern Scott County ( due mostly to excessive August rains as previously highlighted ).

Another August-September rain max of 14"-16"+ occurred along eastern flanks of the Blue Ridge escarpment in the Meadows of Dan to Stuart area. 


( M ) - Denotes missing data during the year from evaporation and losses in snow ( too deep for the rain gage to physically contain ).

*Moisture losses at Big Cherry Dam are estimated to be just over 3.00" during 2010 ( 14 days with potential evaporation from the rain gage were observed during September 2010 alone ).


Tennessee Valley Divide
Long Ridge of Sandy Ridge - September 18, 2010
Myriad of Mountain Ridges - Late Summer Morn
Photograph by Wayne Riner - © All Rights Reserved.


West Virginia

Alderson
September Rainfall: 1.86"
August-September Rain: 4.74"
2010 Precipitation: 23.68"

Bluestone Lake
September Rainfall: 2.37"
August-September Rain: 5.08"
2010 Precipitation: 25.22"

Union 3 SSE
September Rainfall: 2.76"
August-September Rain: 6.18"
2010 Precipitation: 25.68"

White Sulphur Springs
September Rainfall: 1.83"
August-September Rain: 5.29"
2010 Precipitation: 27.09"

Lewisburg 3 N
September Rainfall: 2.04"
August-September Rain: 5.44"
2010 Precipitation: 27.62"
( 1 day missing September )

Buckeye
September Rainfall: 2.61"
August-September Rain: 5.60"
2010 Precipitation: 31.47"
( 1 day missing August )

Elkins
September Rainfall: 4.03"
August-September Rain: 8.89"
2010 Precipitation: 31.74"

Marlinton
September Rainfall: 2.76"
August-September Rain: 5.73"
2010 Precipitation: 33.56"

Huntington
September Rainfall: 2.41"
August-September Rain: 4.92"
2010 Precipitation: 33.62"

Bluefield
September Rainfall: 2.28"
August-September Rain: 6.50"
2010 Precipitation: 34.45"

Beckley
September Rainfall: 1.99"
August-September Rain: 4.70"
2010 Precipitation: 35.16"

Davis 3 SE
( Canaan Mountain )
September Rainfall: 3.62"
August-September Rain: 7.22"
2010 Precipitation: 39.54"

Snowshoe Mountain
September Rainfall: 3.83"
August-September Rain: 9.58"
2010 Precipitation: 52.05"
( 3 days missing during year )

September 26, 2010
Little Stony Basin of High Knob Massif
Multi-colored Shelf Mushroom
Photograph by Roddy Addington - © All Rights Reserved.


North Carolina

Raleigh-Durham
September Rainfall: 6.66"
August-September Rain: 9.72"
2010 Precipitation: 30.79"

Charlotte
September Rainfall: 4.18"
August-September Rain: 8.93"
2010 Precipitation: 32.15"

Asheville
September Rainfall: 4.15"
August-September Rain: 7.62"
2010 Precipitation: 34.57"

Banner Elk
September Rainfall: 2.37"
August-September Rain: 6.33"
2010 Precipitation: 35.67"

Spruce Pine
September Rainfall: 2.87"
August-September Rain: 9.82"
2010 Precipitation: 36.17"

Beech Mountain
September Rainfall: 2.76"
August-September Rain: 7.43"
2010 Precipitation: 37.07"

Mount Mitchell
September Rainfall: 5.94"
August-September Rain: 9.44"
2010 Precipitation: 51.48"
( 3 days missing during year )

Grandfather Mountain
September Rainfall: 3.38"
August-September Rain: 12.85"
2010 Precipitation: 52.98"



Kentucky

Lexington
September Rainfall: 0.61"
August-September Rain: 1.19"
2010 Precipitation: 29.85"

Louisville
September Rainfall: 0.12"
August-September Rain: 2.18"
2010 Precipitation: 29.85"

Frankfort
September Rainfall: 0.31"
August-September Rain: 1.51"
2010 Precipitation: 31.49"



Ohio

Cincinnati
September Rainfall: 0.57"
August-September Rain: 1.71"
2010 Precipitation: 26.48"

Extremely dry September conditions were observed across northern and western Kentucky, southern Indiana and Ohio, with development of moderate to severe drought from the Bluegrass Region northward and southwestward. 


September 21, 2010
Tennessee Valley Divide
View from Guest Mountain of Wise Plateau
Photograph by Roddy Addington - © All Rights Reserved.

[ The extreme eastern end of the High Knob Massif is visible across the right half of the above photo, as it slopes downward like a giant inclined plane into rugged depths of majestic Guest River Gorge south of Coeburn ].



Climatology of October

Historical Temperatures

September 26, 2010
Little Stony Basin of High Knob Massif
Early Autumn Color - Bark Camp Lake
Photograph by Roddy Addington - © All Rights Reserved.

[ Bark Camp Lake is the lowest lake in elevation within the main core of the High Knob Massif, with a full pool water level of 2734 feet above sea level.

High Knob Lake - Elevation 3490 feet
Upper Norton Reservoir - Elevation 3308 feet
Lower Norton Reservoir - Elevation 3230 feet
Big Cherry Lake - Elevation 3120 feet

All of the High Knob Massif lakes, including Bark Camp, sit within cold air drainages which often feature lower night-time temps than those observed along higher, exposed mountain ridges.  ( Many other ponds and wetlands are also present within the massif ) ].

Reference the Hydrology Section of
The High Knob Landform

October typically brings the first snowflakes of the season to mid-upper elevations, and the first frosts of widespread nature to lower elevations ( frost often occurring in colder, mid-upper elevation basins in September ).

Top Ten Coldest October Nights On Record
Wise 1 SE and Wise 3 E
Elevation: 2549 to 2560 feet
Record Period: 1955 to 2009

14 degrees...October 27, 1962
18 degrees...October 24, 1969
20 degrees...October 21, 1974
20 degrees...October 28, 1976
20 degrees...October 29, 1965
20 degrees...October 30, 1968
21 degrees.....October 11, 1964
22 degrees...October 18, 1969
22 degrees...October 20, 1972
22 degrees...October 23, 1997

Since the Wise weather station sits upon an exposed plateau, it can get much colder at night amid the mid-upper elevation valleys that get cold air drainage.

An inspection of the very long record period in Burkes Garden is a good illustration.

Top Ten Coldest October Nights On Record
Burkes Garden Basin
Elevation: 3068 to 3300 feet
Record Period: 1896 to 2009

9 degrees...October 21, 1952
10 degrees...October 22, 1930
10 degrees...October 24, 1904
10 degrees...October 27, 1962
11 degrees.......October 3, 1913
11 degrees....October 23, 1997
12 degrees...October 30, 1965
13 degrees...October 12, 1906
13 degrees...October 28, 1903
13 degrees...October 29, 1952

Although it would be extremely rare for October temperatures to ever break 80 degrees up at the summit level of the High Knob Massif, it can still get warm across lower-middle elevations ( at least during early-mid month ).

Top Ten Warmest October Days On Record
Wise 1 SE and Wise 3 E
Elevation: 2549 to 2560 feet
Record Period: 1955 to 2009

86 degrees...October 8, 2007
84 degrees...October 7, 2007
83 degrees...October 6, 2007
82 degrees....October 2, 1986
82 degrees...October 3, 2007
82 degrees...October 9, 2007
81 degrees....October 4, 2005
81 degrees....October 5, 2005
81 degrees...October 13, 1969
81 degrees...October 12, 1995

The above fact is exemplified by 2007, which not only generated the warmest October temperature ever observed in Wise but also dominates the above record period.  The October 2007 MAX on Eagle Knob of High Knob, at 4178 feet above sea level, reached 76 degrees ( 75.6 ) on October 8. 


October Precipitation

October is the driest month of the year, by far, over the longer term within the High Knob Landform and Cumberland Mountains, with a monthly mean of just 3.08" in the City of Norton ( at Norton WP ) during the 1983-2009 period.

October 2006 has been the wettest in recent years, with 5.23" at Norton WP and locally more than 6.00" across the High Knob Massif.

It appears October 1963 set the benchmark for dryness with only 0.03" in both Pennington Gap and Wise ( all-time least of any month on record ).

Snowfall can occasionally be heavy during October, despite it being the driest month, with most folks remembering the Halloween Snow of 1993 best in recent decades.  Up to 9" or more fell atop the High Knob Massif, with much sticking & melting at all elevations during the prolonged event 
( October 30-November 1 ).

More recently, 1.00" of rain gauge water equivalent was released from a heavy early season fall of snow on Eagle Knob of High Knob during late October 2005. 


The Big Show
October Color Climax

Vivid Autumn Color - October 10, 2008
Photograph by Harold Jerrell - © All Rights Reserved.

October is best known for autumn color which is often simply spectacular across the High Knob Landform.

Reference this section for a look at the October 2009 Climax

Due to a large vertical elevation range, multiple peaks in color can typically be caught as one changes elevation between the Clinch, Powell, and Cumberland river basins and upper elevations of the High Knob Landform.


High Knob Landform ( HKL )
Best Color Periods by Elevation
*( Variation of +/- 7 days )

Early October ( 1-10 )...Upper Elevations > 3000 feet

Mid October ( 10-20 )...Middle Elevations 2000-3000 feet

Late October ( 20-31 )...Lower Elevations < 2000 feet  

*A variation of up to 7 days has been applied to account for the increased seasonal variability observed during the past few decades ( climax generally trending later than average ).

I began documenting climax periods during the 1980s, with these best color periods being representative of the "average" season within the High Knob Massif area.

It is important to emphasize that the “peak” or “climax” is in the eyes of the beholder. What may be peak color to one may not be to another.

Generally "the peak" can not be determined until it has passed, then in retrospect the best color period or climax day(s) can be designated.

I personally consider peak color to occur when there is 75-80% change, with just enough green remaining ( 20-25% ) to round out the autumnal palette!

A wet growing season followed by a drier autumn with bright, sunny days and cool, crisp nights ( non-freezing ) is ideally the perfect recipe for the best autumn color.  At least, on paper.

In reality, Mother Nature deals with many added factors that enter the mix to complicate the autumn color equation.  This being especially true amid complex, mountainous terrain.


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