The High Knob Landform

Thursday, October 7, 2010

October 2010: Majestic Opening To Autumn

October 2, 2010

Little Stony Basin of High Knob Massif

Majestic Autumn Morning - Bark Camp Lake

Photograph by Roddy Addington - © All Rights Reserved.

The High Knob Landform

Morning light and autumn colors painted a grand scene at Bark Camp Lake on October 2nd, creating a wonderful day for those lucky enough to attend the 4th Annual High Knob Naturalist Rally that was sponsored by The Clinch Coalition.

Jefferson National Forest

Bark Camp Lake of High Knob Massif

Misty Steam Fog Dazzles In Morning Light

With morning temperatures in the lower-middle 30s in higher mountain basins, air above the relatively warm water of Bark Camp Lake was plenty cold enough to generate some vigorous displays of misty steam fog!

Bark Camp Lake - October 2, 2010

Spectacular Display of Light & Vapor

Captured by the gifted photography of my friend Roddy Addington, this was a spectacular display of light, color, and condensing vapor.

October 2, 2010
Beautiful Land Snail - Bark Camp Lake

The beauty enjoyed by all creatures great and small on this day gave way to several days of cold, swirling fog, drizzle, light rain, and even a few snowflakes on the peaks during October 3-5.

Temperatures held in the 30s by day and night on Eagle Knob of the High Knob Massif during October 3-4, finally managing to just ease above 40 degrees during October 5.

Climate Example

Early Evening of October 8, 2010

I have always loved the cool, crisp nights that come with the arrival of autumn. On seemingly tranquil evenings this time of year generates some very interesting weather variations!

For example, take the early evening of October 8 when clear skies and calm winds were setting up an ideal radiational cooling and cold air drainage night in the mountains.

At 7 PM, or right at sunset, temps varied from
50-55 degrees in the higher mountain valleys of the High Knob high country ( above 2500 feet ) to 70-76 degrees across lower elevations ( below 2000 feet ) of the Kentucky foothills and Great Valley of
eastern Tennessee.

The 7 PM temperature was in the upper 50s on Eagle Knob of the High Knob Massif, at 4178 feet above sea level, as well as in the Norton Valley of the City ( 2000+ feet lower in elevation ).

An inflection point of equality not to be observed again until after sunrise on the following day, with rises, since evening and overnight cooling with drainage would take temps in the Norton Valley well below those along the high crestlines exposed to light winds ( 20-30+ degree temp differences arising at times ).

Such contrast's supporting earlier autumn color peaks and later spring emergence within the High Knob Massif area that this website has well illustrated since autumn 2009.

Reference the following for detailed spring emergence examples:

HKL Spring Differences: Elevation + Latitude

Most interesting, since many elevated basins are contained in the High Knob Massif, radiational cooling and cold air drainage into high valleys gets a jump start by naturally cooler temperatures along the crestlines, with upper 50s on Eagle Knob at sunset easily cooling to around 50 degrees via downward flow of dense air and radiation amid lower dewpoints ( drier air ) at high elevations.

Visitors or campers at Bark Camp Lake, as one example, can easily feel the drainage and cooling of air as it flows downward through its basin near sunset on such evenings.

The above being highlighted since such significant early evening cooling ( and general noctural cooling ) would not be possible without terrain high enough to reach up into lower dewpoint air, and elevated valleys capable of rapidly collecting it.

Max cooling potential is often never reached in valleys lying below 1500 feet, even beneath highly elevated ridges, since there is some compressional warming with downard drainage of air that eventually begins to offset its higher density ( especially if the air sinks 2000-3000+ feet ).

Otherwise, lower ridges or hills are often not high enough in elevation to reach upward into streams of much drier air aloft and to feed its cooling potential downward into surrounding valleys.

Updated: AM of October 9, 2010

Morning minimums of 30 to 35 degrees were common in mid-upper elevation valleys, from the City of Norton into the High Knob high country.

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

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

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

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

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:

Whitewater Rolls In The High Knob Massif

Climate Statistics
For September 2010

September 26, 2010

Little Stony Basin of High Knob Massif

Scarlet Oak ( Quercus coccinea ) and Gilled Fungi

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 2009 Generates Wetness & Color

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

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

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

[ 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

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

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

[ 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

[ 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

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

High Knob Landform - Glorious Color 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.

Thursday, September 2, 2010

Summer 2010: Wet & Humid In The HKL

Jefferson National Forest

High Knob Lake - Water Elevation 3490 feet

Cool Morning In The Highcountry - Aug 8, 2010

Photograph by Roddy Addington - © All Rights Reserved.

The High Knob Landform

A thin layer of steam fog hovered over the surface of High Knob Lake during one of the few truly cool mornings of August 2010, with 50 to 55 degree minimums within highcountry basins.

[ Some chilly mornings would be felt during the final days of the month, as will be detailed later in this section ].

High Knob Lake Basin - August 2010

Entoloma Mushroom Species In Morning Light

August 2010 is capping off a summer of wetness in the High Knob Landform ( HKL ), with copious rainfall and high humidity levels working in combo to generate an array of atypically warm nights.

High Knob Lake Basin

Fern Growing Inside Tree Covered By Bryophytes

For the vast number of resident fungi, fern, and bryophyte species living within the HKL late spring and summer 2010 has offered nearly ideal growing conditions ( with up to 30+ inches of rain since the beginning of May ).

High Knob Lake Basin

Gorgeous Coral Mushroom - August 2010

Climate Statistics for August 1-20

( A complete recap of August & Summer Stats

will be highlighted after the month ends ).

City of Norton - Elevation 2141 feet

Average Daily MAX: 83.9 degrees

Average Daily MIN: 62.6 degrees

MEAN: 73.2 degrees

Highest Temperature: 89 degrees

Lowest Temperature: 55 degrees

August 1-20 Rainfall: 7.01"

Growing Season Rainfall ( since May 1 ): 23.72"

August 2010 has been the warmest month of the summer, despite its lack of "official" 90 degree days within mid-upper elevations of the High Knob Massif area ( above 2000 feet ).

[ Only 2 days during 2010 ( as of August 20 ) reached 90 degrees in Norton, with no days officially breaking 90 above 2800 feet in elevation ].

It has also turned into the wettest month on average with a general 7.00" to 12.00"+ of rainfall from the City of Norton into the Clinch River Valley of Scott County ( growing season rainfall at Norton Water Plant, since May 1, actually coming in among the lower tallies due to a near record dry July in the City of Norton ).

Powell Valley Overlook of High Knob Massif

An August Jungle In The Southern Appalachians

Wispy fog rising upward from jungle-like humidity and wetness has been very common, especially during the convectively active period of August 10-19.

Prelude to Significant Flash Flooding
Documentation of
August 10-19 Period
( Orographics & Feedbacks )

Grindstone Ridge Dome of High Knob Massif

Orographic Cloud - August 11, 2010

Orographics have played more of a role in the rainfall pattern during August, as they did during May & June, after more of a feedback dominated July across the High Knob Landform.

For more information about summer feedbacks and orographic influences on convective patterns, reference the following section of my website:

July 2010: Month Of Weather Extremes!

High Knob Massif - August 11, 2010

Stationary Orographic Clouds at Multiple Levels

Note that orographic comes from the Greek "oros," meaning mountain, and "graphein" meaning to describe, such that an orographic effect is literally a description of the effects of mountains on weather and climate.

Although orographics played a role in numerous torrential rainfall events during August, the wet feedback established over the Scott County side of the massif in July continued to clearly exert an influence by aiding enhancement of rain amounts within the same, general area on consecutive days ( thus, the build up to the significant Scott County flash flooding on August 19 was not just by chance ).

Showers and downpours in thunderstorms got going during August 10, with 0.50" to 1.00"+ of Doppler estimated rain in the area of The Glades of the High Knob Massif.

JKL Doppler Rainfall Estimate at 10:59 PM - Aug 10

Image Courtesy of Plymouth State University

The above was verified by mushroom and berry hunter Johnny Stanley who got caught under a deluge in the Edith Gap section of the massif near The Glades ( in northern Scott County ).

[ Johnny reported that rain fell so fast that it overflowed the ditch lines, with torrents running across several roadways ].

JKL Doppler Rainfall Estimate at 11:00 PM - Aug 11

Image Courtesy of Plymouth State University

Large thunderstorms developed above the High Knob Massif during August 11, with a notable southwestward propagation across the very long backslope of the massif in northern Scott County ( from The Glades to the Duffield Valley & Stickleyville Basin of northeastern Lee County ).

More Orographic Clouds Visible On Wise County Side

Large Thunderstorms Build Over Massif - Aug 11

My friend & photographer Roddy Addington documented these thunderstorms on August 11, which dropped Doppler estimated 1.00" to 3.00" rainfall amounts from South Fork Gorge and the lower Big Cherry Basin of Wise County across much of the Scott County side of the massif.

August 11, 2010
Powell Valley Overlook of High Knob Massif

Trailing Inflow - Thunderstorms Move SE Off Massif

Formation of these thunderstorms marked an important turning point for the drought baked Tri-Cities of northeast Tennessee, with movement off the High Knob Landform and its remnant massif of highcountry into the lower terrain of the Great Valley where 1.20" of rain officially fell at TRI ( marking the first 1.00"+ rain event in 3 LONG, dry months! ).

[ By no coincidence, the TRI would go on to receive several more needed downpours during the next week as a DENT was finally put into its rain hindering dry feedback shield courtesy of storms erupting above the wetness of the High Knob Landform ( HKL ) ].

August 11, 2010
Sky Turns Colorful In Wake of Storms

The focus of storm formation during August 12 again zeroed in on the South Fork Gorge to Cove Creek Gorge section of the massif, with Maple Gap, Thunderstruck Knob, and the upper Stock Creek Basin all getting in on Doppler estimated 1.00" to 1.50"+ rainfall amounts.

JKL Doppler Rainfall Estimate at 11:00 PM - Aug 12

Image Courtesy of Plymouth State University

[ Another corridor of concentrated heavy rains developed from southeastern slopes of the High Knob Massif across a portion of the Clinch River Valley and Copper Ridge of Scott County ].

The next huge thunderstorms went up over the High Knob Massif into early afternoon hours of August 13, with great cumulonimbus towers soaring 8 to 10 vertical miles into the heavens!

2-Day Doppler Estimate

JKL Doppler Rainfall Estimate at 11:01 PM - Aug 13

Image Courtesy of Plymouth State University

Booming thunder from these giants could be heard all the way north to Clintwood, with huge tops being clearly visible toward the south and southwest.

Doppler Base Reflectivity at 2:58 PM - August 13, 2010

Image Courtesy of Plymouth State University

Day turned to night as 1.00" to 1.50"+ rains fell from parts of Wise southeast into the highcountry around the High Chaparral and Robinson Knob communities of High Knob.

The most intense rains fell with repetitive backbuilding along the northwestern flank of the HKL, with Doppler estimated 2.00" to 3.00" rain amounts between High Butte and the "Big Stone Gap" of Stone Mountain ( southwestern Wise County ).

Otherwise, the big storms of this afternoon laid down additional heavy rains upon the same places already hit hard by August 11-12 storm activity across northern Scott County.

3-Day Rainfall Estimate

JKL Doppler Rainfall Estimate at 2:59 AM - Aug 15

Image Courtesy of Plymouth State University

With a few additional August 14 storms the area inside of the white ellipse illustrated previously was well covered by the early hours of August 15 ( having only a few embedded dry pockets ).

August 2010

Mushroom In High Knob Lake Basin

A welcomed break was observed across most of the area during August 15, with only a few isolated exceptions from Guest River Gorge into the Clinch River Valley and Tennessee Valley Divide.

JKL Doppler Rainfall Estimate at 10:58 PM - Aug 15

Image Courtesy of Plymouth State University

Trouble Ahead Revealed
In Series of Sunrise Photographs

August 16, 2010

High Knob Massif from Powell Valley

Orographic Wave Clouds In Morning Light

A simply gorgeous set of sunrise photographs captured by Roddy Addington from the rolling floor of majestic Powell Valley, in Wise County, Va., might initially appear innocent enough.

Second View in Time Series

Wave Clouds In August Sunrise - August 16, 2010

Wave clouds above the High Knob Massif are a common sight during much of the year, but are expected from a climatological perspective to be observed least during the month of August.

[ August typically possesses the lightest wind fields of the year, such that orographic forcing is generally weak and not conducive to driving wave cloud formation off the terrain ].

Third & Final View in Morning Series

Stacked Lenticular Forms - August 16, 2010

This morning sunrise series revealed that not only are these orographic wave clouds, but that they are a very special form known as stationary lenticular clouds ( although not as spectacular as many observed during the orographic forcing season from Nov-April ).

[ Lenticular wave clouds are not expected in August, with these forming in 15 knots of NW flow near and just above the summit level of the High Knob Massif ].

Any time gravity waves are present they indicate that both vertical and horizontal energy transfer is likely, which during the summer season can be especially important given large amounts of CAPE ( Convective Available Potential Energy ) latent within high dewpoint air ( also suggested by abundant fog in above photographs along Powell Valley floor and walls ).

Gravity waves tend to form concentrations of cloud water vapor in their ascent regions that are richer than those generated only by upsloping alone, such that they can aid rainfall enhancement ( under and adjacent to their gravity wave source area ).

NAM Model Initialization at 8 AM on August 16, 2010

Image Courtesy of Unisys Weather Processor

An inspection of morning weather charts revealed the setting, with NW wind vectors visible on the 850 mb panel in upper left representing the air flow pushing against the High Knob Massif.

The massif was in turn forcing gravity wave formation, with the lenticular clouds visible in the above photographs standing at the crest of the wave ( like at the top of an ocean wave ).

The upper right panel above supports this rather anomalous setting by showing an actual phasing, or coupling, of Pacific & Polar jet streams that is more analogous to an autumn or winter setting, with atypically strong westerly winds aloft flowing across the Ohio Valley.

NAM Model Initialization at 8 PM on August 16, 2010

Image Courtesy of Unisys Weather Processor

A strong cold front to the northwest, driven by anomalously deep low pressure over Hudson Bay in Canada, was becoming aligned along a strong moisture and instability gradient easing southeast across Kentucky during the day ( much more stable, drier air north to northwest of the mountains can be noted on the lower right chart above ).

Something had to give!

Doppler Base Reflectivity at 6:49 PM on August 16

Image Courtesy of Plymouth State University

And, of course, it was MORE thunderstorms!

2-Day Doppler Totals

JKL Doppler Rainfall Estimate at 9:56 PM on Aug 16

Image Courtesy of Plymouth State University

The heaviest rains became concentrated along the Clinch River Valley, with widespread 0.50" to 2.50"+ amounts again falling upon the High Knob Massif of northern Scott County into Big Cherry Basin of Wise County.

These storms were only the beginning of an all out assault by Mother Nature, as the above parameters would combine with the northeastward surge of remnant moisture from Tropical Depression 5 to force 17.5 vertical feet of rise on the Clinch River, downstream of the High Knob Massif, by late on August 19 ( details and flood pictures to follow below ).

JKL Doppler Rainfall Estimate at 11:00 PM on Aug 17

Image Courtesy of Plymouth State University

The first wave of tropical moisture worked across the Tennessee Valley during August 17 with destructive aim taken once again on already water logged Scott County, Va., as torrential rains set up along and southeast of the High Knob Landform.

[ The heaviest 2.00" to 3.00"+ Doppler estimates falling from the Rye Cove Basin east and southeast across the Clinch River into portions of Copper Ridge and Clinch Mountain ].

The terrible and tragic death of a Weber City teenager, who got swept into a storm drain by flood waters on this evening, added to a horrible list of flood related deaths in the region this year.

NAM Model Initialization at 8 AM on August 18, 2010

Image Courtesy of Unisys Weather Processor

Daylight hours of August 18 were dominated by low clouds, fog, and a shield of light to moderate rain from the High Knob Landform west and north.

[ Temperatures remained relatively cool, with narrow spreads between day and night. MAXS in the 60s to lower 70s and MINS in the 60s indicated that it also remained plenty humid enough for more heavy rain! ].

NAM Model Initialization at 8 PM on August 18, 2010

Image Courtesy of Unisys Weather Processor

[ Note the surface low over Arkansas and the 850 MB low over western Tennessee, on the above charts, representative of the remnants of Tropical Depression 5 ].

Heaviest local rain totals during August 18 were observed along northern slopes of the High Knob Massif, with 1.00" to 1.50" from Appalachia and Norton to Tacoma and Coeburn.

It was a miracle, pure and simple, that flooding rains which fell through morning hours of August 18 across southern Kentucky and the northern Cumberland Plateau of Tennessee did not reach into the mountains of southwestern Virginia.

Graphic Courtesy of Jackson, Ky., NWSFO

However, another batch of tropical moisture was surging north into middle Tennessee as displayed within the BLUE outline below on Water Vapor imagery.

NASA Water Vapor Image at 5:15 PM on August 18

While seeming to weaken, with Doppler radar looking rather anemic by late evening of August 18, a real fear remained alive in the minds of those who understood that remnant tropical systems often go through distinct diurnal cycles which force inflow and convergence to begin during the night!

Flash Flood - River Flood Event

( August 19, 2010 )

Doppler Base Reflectivity at 5:30 AM - August 19

Image Courtesy of Plymouth State University

That was certainly the case as heavy overnight rains and downpours developed quickly into the predawn hours of August 19 with a rapid spread northeast along the High Knob Landform and Upper Tennessee River Basin.

NAM Model Initialization at 8 AM on August 19, 2010

Image Courtesy of Unisys Weather Processor

Morning weather charts revealed a weak low pressure that were the remnants of former TD 5 . This supported enhanced convergence of moist, tropical air along its path and into the HKL and its massif of highcountry.

3-Day Rainfall Estimate

Doppler Radar Rainfall Estimate at 5:58 PM on August 19

Image Courtesy of Unisys Weather Processor

Although the above graphic looks impressive, Doppler radar actually under-estimated rainfall totals that were measured by rain gauges during August 18-19. This being due to the fine dropped, fast falling tropical rains and to the orographic enhancement of rainfall across the High Knob Massif along the borders of Wise, Scott, and Lee counties ( due to the torrential nature of this rainfall, tipping-bucket gauges also recorded less than hand-measured gauges ).

Flood Photographs

( A Few Examples of Many )

The following photographs were submitted by viewers to meteorologist Dave Dierks & the News 5 weather team of WCYB-TV in the Tri-Cities of northeast Tennessee.

August 19, 2010

Flash Flooding - Fort Blackmore Area of Scott County

Photograph by Megan Darnell

Significant flash flooding developed all along the rugged Wise, Scott, and Lee county borders as very steep creeks draining the High Knob Massif funneled water into the Clinch-Powell rivers.

Some of the worst conditions developed across Scott County, Va., from Dungannon southwest to Fairview and The Sinks.

Flash Flooding In Dungannon Area - August 19, 2010

Photograph by Roger Hall

At least half a dozen families had to evacuate homes along Big Stony Creek in northern Scott County, marking the third time that some had to flee their residences during this very wet mid-July to mid-August period of 2010 ( a dangerous situation, with the flood plain of Big Stony Creek being one of the most flashy and potentially deadly in the entire region ).

August 19, 2010

Flooding in Fort Blackmore Area of Scott County

Photograph by Meagan Peak

Flash flooding became widespread along North Fork of the Clinch River which flows by Jasper and through The Divide into the Duffield Valley, The Sinks, Fairview, and Jennings Store from its head near the Wise-Lee border in the High Knob Massif.

August 19, 2010

Flash Flooding in Duffield - North Fork of Clinch River

Photograph by Dorothy Ricord

A river gage in Speers Ferry recorded an impressive 17.46 feet of vertical rise on the Clinch River, which remained above flood stage for just over 12-hours ( all the water seen in the above photograph, and the one below, dumping into the mainstem Clinch River downstream of Speers Ferry near Kyles Ford, Tn., and not included in the Speers Ferry rise ).

August 19, 2010

Flooding in the Fairview Community of Scott County

Photograph by Allen Vanstant

Flash flooding also developed within the Powell River watershed of Wise County, Va., as water gushed out of lofty Big Cherry Basin and off the steep northwestern slopes between Big Stone Gap and Norton ( look for a Big Cherry Dam precip update later ).

August 19, 2010

Flooding In Cracker Neck of Powell Valley

Photograph by Mike Brady

Way too many homes had water surround them during this event, to make the meek showers and brief downpours of the August 21-22 weekend a welcomed sight as the heaviest passed just south of Scott County, Virginia. Finally, a miss!

August 19, 2010

Mobile Homes In Dungannon Area of Scott County

Photograph by Shirley Forman

More downpours of rain developed across the High Knob Massif during August 26, with a notable concentration again across northern Scott County into the Clinch Valley of Russell County ( with 0.50" to 1.00" rainfall amounts ).

Doppler Radar Rainfall Estimate at 4:43 PM on August 26

Image Courtesy of Plymouth State University

This was part of a period that finally featured cooler nights, with low-mid 50s dominating higher mountain valleys during the August 23-31 period.

[ August 31 featuring the coolest morning of the month, with middle 40s to lower 50s being common in fog free valleys of mid-upper elevations ].

Climate Statistics For
August 2010

High Knob Massif - August 2010
Monarch Butterfly's ( Danaus plexippus )
On Beautiful Milkweed ( Asclepias spp. )

August 2010 ended warmer & wetter than average despite somewhat cooler air during the final ten days of the month across the High Knob Landform ( drier than normal N-NE of the HKL ).

Clintwood 1 W - Elevation 1560 feet

Average Daily MAX: 82.9 degrees

Average Daily MIN: 63.3 degrees

MEAN: 73.1 degrees

Highest Temperature: 90 degrees

Lowest Temperature: 57 degrees

August Rainfall: 3.73"
Summer Rainfall: 13.06"

2010 Precipitation: 31.97"
( -1.21" below 1971-2000 mean )

Breaks Interstate Park - Elevation 1893 feet
Average Daily MAX: 78.9 degrees
Average Daily MIN: 63.6 degrees
MEAN: 71.2 degrees
Highest Temperature: 86 degrees
Lowest Temperature: 57 degrees
August Rainfall: 1.65"
Summer Rainfall: 13.33"
2010 Precipitation: 32.24"
( 1 day missing in May )

City of Norton - Elevation 2141 feet

Average Daily MAX: 82.6 degrees

Average Daily MIN: 60.2 degrees

MEAN: 71.4 degrees

Highest Temperature: 89 degrees

Lowest Temperature: 53 degrees

August Rainfall: 7.65"
Summer Rainfall: 15.76"

2010 Precipitation: 39.13"
( -1.57" below 1983-2004 mean )

Long Ridge of Sandy Ridge

Nora 4 SSE - Elevation 2650 feet

Average Daily MAX: 80.7 degrees

Average Daily MIN: 65.3 degrees

MEAN: 73.0 degrees

Highest Temperature: 88 degrees

Lowest Temperature: 59 degrees

August Rainfall: 5.95"
Summer Rainfall: 14.36"

2010 Precipitation: 34.42"

In the High Knob highcountry August temp means varied from 70s by day above 2700 feet to mid-upper 50s by night in the cooler mountain basins ( August MINS reaching middle 40s to lower 50s ).

August rainfall totals were excessive across the High Knob Massif, varying from 6.66" on its rugged Little Stone Mountain arm, at Appalachia Lake Water Plant ( 6.7 air miles WSW of Norton WP ), to as much as 15.00" in the multi-gorge Big Stony Basin of northern Scott County.

( Updated August 4, 2012 )

Generalized Map of August 2010 Rainfall Totals

Climatology reveals that when there is a concentration of excessive precipitation across the High Knob Massif there tends to be a compensating area of enhanced subsidence and sinking of air, with much less precipitation, across the Russell Fork & Levisa Fork basins of the Big Sandy River given trajectories of air flow possessing southern components.

August 31, 2010

Morning Inversion In The High Knob Landform

Looking southwest along the Powell River Valley, nestled between Wallen Ridge and the northwestern arm of the High Knob Landform, a layer of fog illustrates a strong morning temperature inversion to close out August 2010.

Sunrise temperatures varied from middle 40s to lower 50s in cooler basins of the High Knob highcountry to mid 60s in places well exposed to light winds.

Big Cherry Dam of High Knob Massif

Monthly Precipitation Totals

Elevation 3120 feet

2009

September: 9.09"

October: 4.36"

November: 3.88"

*December: 11.50"

2010

*January: 6.25"

*February: 4.25"

*March: 4.50"

April: 3.78"

May: 6.99"

June: 9.53"

July: 4.27"

August: 8.91"

Summer 2010 Total: 22.71" ( M )

( May-August )
Growing Season 2010: 29.70" ( M )

2010 Precipitation Total: 48.48" ( M )

12-Month Total: 77.31" ( M )

21-Month Total: 138.31" ( M )
( Mean of 6.59" per month )

24-Month Total: 148.06" ( M )
**( Mean of 6.17" per month )

( * ) - Denotes data loss during the harsh 2009-10 winter.

( M ) - Denotes that the actual total fall was greater than rain gauge amounts due to a combination of evaporation between the hand-measurements and losses amid wind & sub-freezing conditions.

( ** ) - With up to 6.00"+ of loss figured during the past 24 months ( September 2008 - August 2010 ) due to evaporation between the hand-measurements, a much more accurate mean monthly precipitation value would be approximately 6.42" per month.

[ Evaporation from the rain gauge varying from only 0.01" per week up to around 0.10" per week, with an estimated mean of 0.05" to 0.06" per week. This is only from physical gauge loss and does not account for any losses due to wind induced undercatch in rain and frozen precipitation forms.

It also does not account for occasional significant losses in deep falls of snow, and does not account for any of the very important secondary additions to the water budget of Big Cherry Basin from fog drip off trees and rime deposition on trees. ].

Note: All hand-measurements at Big Cherry Dam are courtesy of Gary Hampton, Superintendent of the Big Stone Gap Water Plant, and his staff.

August 31, 2010

Morning Inversion Inside High Knob Massif

At about this time last year there had been an estimated 3.00" of evaporative loss at Big Cherry Dam, due to hand-measurements which average one per every 5 to 7 days ( based upon observed losses at my Clintwood NWS station for evaporation ).

During 2010 the loss from evaporation is figured to be about the same, despite warmer mean temps, since higher average humidity levels have tended to offset increased evaporation from higher average temperatures ( at least within the wetter, cloudier High Knob Massif area ).

Regardless of the exact value, it is certain that more than 30.00" of rain has accumulated across Big Cherry Basin since May 1 and the start of the growing season ( more than 50.00" of total precip in 2010, and 80.00"+ during the past 12-months, with addition of only the approximate evaporative losses from the rain gauge ).

August 2010

Mushroom Weather - High Knob Massif

Photograph by Roddy Addington - © All Rights Reserved.

Growing Season Rainfall
*Big Cherry Basin MAX Totals
( May 1 to August 31 of 2010 )

May: 10.00"

June: 9.75"

July: 6.25"

August: 9.00"

Rainfall Total: 35.00"

*Doppler radar estimated 8.00" to 10.00" of rain across Big Cherry Basin during August, with the mean value being used. Much more rain is known to have fallen across the middle-upper basin during May, with significantly more also in July, than at the Big Cherry Dam measuring point.

Big Cherry Lake gained 55.9 million gallons of water during the August 10-20 period, with a 37.3 million gain during August 16-20 when 5.74" of rain were measured at the Dam ( more than 6.00" fell along Little Mountain during that period ).

The Lake overflowed its spillway during the final 13 days of August ( such that the total amount gained and spilled out of the Big Cherry Basin was much more than 55.9 million gallons ).

High Knob Lake Basin - August 2010

Eastern Tiger Swallowtail ( Papilio glaucus )

Silver-spotted Skipper ( Epargyreus clarus )

and Milkweed Bug on ( Asclepias spp. )

For August 2010

Jackson, Ky., NWSFO - Elevation 1365 feet

Average Daily MAX: 87.0 degrees

Average Daily MIN: 67.7 degrees

MEAN: 77.4 degrees

Highest Temperature: 97 degrees

Lowest Temperature: 62 degrees

August Rainfall: 3.51"
Summer Rainfall: 12.45"

2010 Precipitation: 32.79"

London, Kentucky - Elevation 1211 feet

Average Daily MAX: 87.5 degrees

Average Daily MIN: 67.3 degrees

MEAN: 77.4 degrees

Highest Temperature: 95 degrees

Lowest Temperature: 59 degrees

August Rainfall: 6.03"
Summer Rainfall: 14.48"

2010 Precipitation: 32.74"

Buckhorn Lake State Park, Ky., - Elevation 780 feet

Average Daily MAX: 88.8 degrees

Average Daily MIN: 66.8 degrees

MEAN: 77.8 degrees

Highest Temperature: 98 degrees

Lowest Temperature: 57 degrees

August Rainfall: 7.92"
Summer Rainfall: 16.10"

2010 Precipitation: 33.33"

Tri-Cities, Tennessee - Elevation 1525 feet

Average Daily MAX: 89.6 degrees

Average Daily MIN: 66.5 degrees

MEAN: 78.0 degrees

Highest Temperature: 96 degrees ( 3 days )

Lowest Temperature: 58 degrees

August Rainfall: 6.26"
Summer Rainfall: 10.80"

2010 Precipitation: 23.50"

Knoxville, Tennessee - Elevation 981 feet

Average Daily MAX: 91.4 degrees

Average Daily MIN: 71.4 degrees

MEAN: 81.4 degrees

Highest Temperature: 98 degrees

Lowest Temperature: 64 degrees

August Rainfall: 2.80"
Summer Rainfall: 9.94"

2010 Precipitation: 28.54"

Chattanooga, Tennessee - Elevation 683 feet

Average Daily MAX: 94.4 degrees

Average Daily MIN: 73.7 degrees

MEAN: 84.0 degrees

Highest Temperature: 101 degrees

Lowest Temperature: 65 degrees

August Rainfall: 3.05"
Summer Rainfall: 7.91"

2010 Precipitation: 29.04"

Roanoke, Virginia - Elevation 1175 feet
Average Daily MAX: 86.4 degrees
Average Daily MIN: 67.9 degrees
MEAN: 77.2 degrees
Highest Temperature: 97 degrees
Lowest Temperature: 61 degrees
August Rainfall: 5.00"
Summer Rainfall: 12.01"
2010 Precipitation: 29.35"

Richmond, Va., ( State Capitol ) - Elevation 167 feet
Average Daily MAX: 89.9 degrees
Average Daily MIN: 69.9 degrees
MEAN: 79.9 degrees
Highest Temperature: 98 degrees
Lowest Temperature: 64 degrees
August Rainfall: 3.92"
Summer Rainfall: 5.93"
( 3rd driest Summer on Record )
2010 Precipitation: 22.73"

August 31, 2010

Morning Inversion - Powell Valley of HKL

Photograph by Roddy Addington - © All Rights Reserved.

Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 83.2 degrees
Average Daily MIN: 61.9 degrees
Summer MEAN: 72.6 degrees

Breaks Interstate Park - Elevation 1893 feet
Average Daily MAX: 79.0 degrees
Average Daily MIN: 63.1 degrees
Summer MEAN: 71.0 degrees

City of Norton - Elevation 2141 feet
Average Daily MAX: 82.6 degrees
Average Daily MIN: 59.5 degrees
Summer MEAN: 71.0 degrees
Highest Temperature: 91 degrees
Lowest Temperature: 44 degrees
Number of days at or above 90: 2

Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 80.7 degrees
Average Daily MIN: 64.8 degrees
Summer MEAN: 72.8 degrees
Highest Temperature: 91 degrees
Lowest Temperature: 54 degrees
Number of days at or above 90: 2

Burkes Garden - Elevation 3068 feet
Average Daily MAX: 79.6 degrees
Average Daily MIN: 57.1 degrees
Summer MEAN: 68.4 degrees
Highest Temperature: 88 degrees
Lowest Temperature: 39 degrees

In the High Knob highcountry mean summer temperatures varied from 70s by day to 50s at night to generate averages in the 60s for most locations.

[ An abundance of summer rainfall and clouds, as highlighted above, helping hold daytime temperatures down while making nights milder than average ( but still comfortable across the massif relative to those places experiencing record summer heat as highlighted below ) ].

As noted by Breaks Interstate Park above, with a shady northern exposure, there were some exceptions as the coolest mean daily maximums occurred on north slopes across a broad elevation range ( the coolest locations generally being on N-NE sides of high valleys, with nocturnal cold air drainage also acting to reduce daily means amid these lofty basins ).

Coolness was relative, as for nearly all locations and elevations it was a summer of above average to even record level heat ( record heat being widespread with dryness in the Great Valley of eastern Tennessee and across much of Virginia to the east and southeast of the Clinch-Powell basins ).

( June-August of 2010 )

Hottest Summer On Record

Across Great Valley of East Tennessee

It is now official that Summer 2010 was the hottest of all-time in the Great Valley of eastern Tennessee ( while linked to a dry feedback this is still very impressive! ).

Tri-Cities ( TRI )

Mean Summer Temperature: 77.3 degrees

( Warmest since record keeping began in 1934 )

Knoxville ( TYS )

Mean Summer Temperature: 81.0 degrees

( Beat out the 80.1 degree mean in Summer 1936 )

Chattanooga ( CHA )

Mean Summer Temperature: 83.0 degrees

( Beat out 82.0 degrees for Summer 1993 )

Although summer rainfall was not nearly the lowest on record, especially at TRI thanks to a wet turn in August, much of Summer 2010 was dry to contribute to these impressive levels of heat!

( June-August of 2010 )

Hottest Summer On Record

Virginia & District of Columbia

Summer 2010 was also the hottest across much of Virginia, and in the National Capitol district.

Blacksburg

Mean Summer Temperature: 72.9 degrees

( Record keeping began in 1952 )

Bluefield

Mean Summer Temperature: 74.5 degrees

( Record keeping began in 1959 )

Roanoke

Mean Summer Temperature: 78.2 degrees

( Record keeping began in 1912 )

Danville

Mean Summer Temperature: 80.0 degrees

( Record keeping began in 1948 )

Norfolk
Mean Summer Temperature: 81.1 degrees
( Previous record was 80.0 degrees in Summer 1994 )

Richmond
Mean Summer Temperature: 81.3 degrees
( Beat out the 79.6 degrees in Summer 1900 )

Washington D.C.

Mean Summer Temperature: 81.3 degrees

( Record keeping began in 1872 )

One of the hottest places in Virginia during Summer 2010 was Hopewell, in Prince George County, with a blazing mean of 82.6 degrees via 92.7 degrees by day and 72.4 degrees at night.

Driving these amazing records at so many places has been a record number of days above 90 degrees, from TRI to Washington D.C., with the mean summer max of 90.2 degrees in the Nation's Capitol marking the first time since 1872 that the average daily high for the entire summer has been above 90.

[ More than 50 days of 90+ degree heat became an all-time record for TRI, with Washinton D.C. also on pace to break its all-time number of 90 degree days in a year ( 67 set in 1980 ) ].

However, the most common denominator was record warm nights at nearly all locations setting new marks for mean summer temperatures!

[ Mean summer MINS were unusually warm across the High Knob Landform, with only higher valleys and the highest crestlines having average lows in the 50s ].

August 2010

High Knob Lake Basin
Swallowtail's and Milkweed ( Asclepias spp. )

[ Note: All 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. ].

Virginia & District of Columbia

Woodstock 2 NE
August Rainfall: 1.36"
Summer Rainfall: 3.78"
May-August Rain: 6.53"
2010 Precipitation: 17.70"
( 1 day missing in July )

Dale Enterprise
August Rainfall: 2.26"
Summer Rainfall: 5.57"
May-August Rain: 8.17"
2010 Precipitation: 18.45"

Madison
August Rainfall: 1.54"
Summer Rainfall: 4.26"
May-August Rain: 7.34"
2010 Precipitation: 20.58"

Washington D.C. - National Airport
August Rainfall: 2.59"
Summer Rainfall: 9.63"
May-August Rain: 12.03"
2010 Precipitation: 21.36"

Orange
( Piedmont Research Station )
August Rainfall: 2.59"
Summer Rainfall: 6.49"
May-August Rain: 9.56"
2010 Precipitation: 21.41"

Staunton Water Plant
August Rainfall: 2.53"
Summer Rainfall: 7.43"
May-August Rain: 10.84"
2010 Precipitation: 21.81"

Pulaski 2 E
August Rainfall: 4.07"
Summer Rainfall: 7.24"
May-August Rain: 9.52"
2010 Precipitation: 21.99"

Edinburg
August Rainfall: 2.28"
Summer Rainfall: 9.66"
May-August Rain: 12.12"
2010 Precipitation: 22.04"

Charlottesville
August Rainfall: 2.36"
Summer Rainfall: 6.08"
May-August Rain: 9.65"
2010 Precipitation: 22.45"

Richmond
August Rainfall: 3.92"
Summer Rainfall: 5.93"
May-August Rain: 8.55"
2010 Precipitation: 22.73"

Winchester
August Rainfall: 1.49"
Summer Rainfall: 6.36"
May-August Rain: 9.11"
2010 Precipitation: 23.28"

Warsaw 2 NW
August Rainfall: 4.12"
Summer Rainfall: 6.97"
May-August Rain: 8.55"
2010 Precipitation: 23.35"

Gathright Dam
August Rainfall: 3.70"
Summer Rainfall: 7.73"
May-August Rain: 12.78"
2010 Precipitation: 23.44"

Covington Filter Plant
August Rainfall: 2.82"
Summer Rainfall: 8.51"
May-August Rain: 12.56"
2010 Precipitation: 23.67"

Eastville
August Rainfall: 3.40"
Summer Rainfall: 8.04"
May-August Rain: 10.54"
2010 Precipitation: 24.66"
( 2 days missing June / 1 day July )

Suffolk Lake Kilby
August Rainfall: 2.44"
Summer Rainfall: 7.16"
May-August Rain: 10.93"
2010 Precipitation: 24.91"

Shenandoah 1.4 N
August Rainfall: 3.24"
Summer Rainfall: 12.55"
May-August Rain: 15.07"
2010 Precipitation: 25.61"
( 4 days missing during year )

Lexington
August Rainfall: 1.73"
Summer Rainfall: 9.32"
May-August Rain: 13.20"
2010 Precipitation: 25.67"

Christiansburg
August Rainfall: 4.85"
Summer Rainfall: 9.19"
May-August Rain: 14.33"
2010 Precipitation: 25.77"

Louisa
August Rainfall: 2.79"
Summer Rainfall: 8.17"
May-August Rain: 12.83"
2010 Precipitation: 25.79"

Buena Vista
August Rainfall: 4.02"
Summer Rainfall: 11.08"
May-August Rain: 13.64"
2010 Precipitation: 25.91"

West Point 2 NW
August Rainfall: 2.26"
Summer Rainfall: 6.82"
May-August Rain: 9.88"
2010 Precipitation: 25.97"

Williamsburg 2 N
August Rainfall: 2.34"
Summer Rainfall: 7.38"
May-August Rain: 10.28"
2010 Precipitation: 26.22"

Buckingham
August Rainfall: 3.54"
Summer Rainfall: 6.79"
May-August Rain: 12.77"
2010 Precipitation: 26.37"

Abingdon 3 S
August Rainfall: 4.48"
Summer Rainfall: 11.54"
May-August Rain: 14.69"
2010 Precipitation: 26.47"
( 4 missing days during year )

Clifton Forge RAWS
( U.S. Forest Service )
August Rainfall: 2.16"
Summer Rainfall: 8.02"
May-August Rain: 14.78"
2010 Precipitation: 26.56"

Washington D.C. - Dulles Airport
August Rainfall: 4.42"
Summer Rainfall: 9.88"
May-August Rain: 15.30"
2010 Precipitation: 26.59"

Luray 5 E
August Rainfall: 3.75"
Summer Rainfall: 10.31"
May-August Rain: 13.59"
2010 Precipitation: 26.80"

Somerset
August Rainfall: 2.63"
Summer Rainfall: 8.00"
May-August Rain: 12.57"
2010 Precipitation: 26.90"

Hopewell
August Rainfall: 5.79"
Summer Rainfall: 9.48"
May-August Rain: 14.27"
2010 Precipitation: 27.44"

Wallops Island
August Rainfall: 7.78"
Summer Rainfall: 11.31"
May-August Rain: 13.31"
2010 Precipitation: 27.57"

Front Royal
August Rainfall: 4.39"
Summer Rainfall: 8.15"
May-August Rain: 11.32"
2010 Precipitation: 27.66"
( 1 day missing July )

Bland
August Rainfall: 4.62"
Summer Rainfall: 11.48"
May-August Rain: 15.35"
2010 Precipitation: 27.76"
( 5 days missing during year )

Blacksburg
August Rainfall: 5.09"
Summer Rainfall: 10.90"
May-August Rain: 15.79"
2010 Precipitation: 27.81"

Danville
August Rainfall: 5.52"
Summer Rainfall: 9.81"
May-August Rain: 13.83"
2010 Precipitation: 27.86"

Wytheville 1 S
August Rainfall: 6.33"
Summer Rainfall: 12.44"
May-August Rain: 15.17"
2010 Precipitation: 28.05"
( 1 day missing in May )

Appomattox
August Rainfall: 5.41"
Summer Rainfall: 10.59"
May-August Rain: 16.01"
2010 Precipitation: 28.16"

Glasgow 1 SE
August Rainfall: 3.73"
Summer Rainfall: 8.17"
May-August Rain: 11.16"
2010 Precipitation: 28.19"

Kerrs Creek 6 WNW
August Rainfall: 2.75"
Summer Rainfall: 12.28"
May-August Rain: 16.78"
2010 Precipitation: 28.41"

Martinsville Filter Plant
August Rainfall: 4.99"
Summer Rainfall: 8.98"
May-August Rain: 12.62"
2010 Precipitation: 28.52"
( 1 day missing in June )

New Castle RAWS
( U.S. Forest Service )
August Rainfall: 6.35"
Summer Rainfall: 12.02"
May-August Rain: 15.82"
2010 Precipitation: 28.98"

Copper Hill
August Rainfall: 4.44"
Summer Rainfall: 9.79"
May-August Rain: 15.00"
2010 Precipitation: 29.08"

Roanoke
August Rainfall: 5.00"
Summer Rainfall: 12.01"
May-August Rain: 17.36"
2010 Precipitation: 29.35"

Mendota 1.6 SW
August Rainfall: 6.49"
Summer Rainfall: 15.20"
May-August Rain: 18.44"
2010 Precipitation: 29.82"

Marion 4.4 WSW
August Rainfall: 5.94"
Summer Rainfall: 14.79"
May-August Rain: 18.67"
2010 Precipitation: 30.70"
( 1 day missing in May )

Independence 2.2 E
August Rainfall: 9.83"
Summer Rainfall: 14.95"
May-August Rain: 18.82"
2010 Precipitation: 31.46"
( 6 days missing during year )

Lebanon
August Rainfall: 6.85"
Summer Rainfall: 14.46"
May-August Rain: 18.78"
2010 Precipitation: 31.54"

Clintwood
August Rainfall: 3.73"
Summer Rainfall: 13.06"
May-August Rain: 18.82"
2010 Precipitation: 31.97"

Grundy
August Rainfall: 2.80"
Summer Rainfall: 14.44"
May-August Rain: 20.46"
2010 Precipitation: 32.03"
( 1 day missing in May )

Breaks Interstate Park
August Rainfall: 1.65"
Summer Rainfall: 13.33"
May-August Rain: 18.53"
2010 Precipitation: 32.24"
( 1 day missing in May )

Lynchburg
August Rainfall: 6.53"
Summer Rainfall: 12.55"
May-August Rain: 17.11"
2010 Precipitation: 32.27"

North Fork of Pound Dam
August Rainfall: 4.07"
Summer Rainfall: 14.07"
May-August Rain: 20.05"
2010 Precipitation: 32.58"

Richlands
August Rainfall: 5.86"
Summer Rainfall: 17.26"
May-August Rain: 21.16"
2010 Precipitation: 32.71"

Norfolk
August Rainfall: 3.59"
Summer Rainfall: 13.19"
May-August Rain: 17.79"
2010 Precipitation: 32.82"

Holcomb Rock
August Rainfall: 6.49"
Summer Rainfall: 12.59"
May-August Rain: 17.39"
2010 Precipitation: 33.55"
( 1 day missing in May )

Wise RAWS
( U.S. Forest Service )
August Rainfall: 6.02"
Summer Rainfall: 11.71"
May-August Rain: 20.39"
2010 Precipitation: 33.65"

Nora 4 SSE
August Rainfall: 5.95"
Summer Rainfall: 14.36"
May-August Rain: 23.07"
2010 Precipitation: 34.42"

Saltville 1 N
August Rainfall: 7.45"
Summer Rainfall: 18.06"
May-August Rain: 23.38"
2010 Precipitation: 34.86"
( 2 days missing June / 3 days August )

Meadows of Dan 4.5 SW
August Rainfall: 6.66"
Summer Rainfall: 14.51"
May-August Rain: 19.79"
2010 Precipitation: 35.74"
( 1 day missing in May )

Burkes Garden
August Rainfall: 6.57"
Summer Rainfall: 14.39"
May-August Rain: 21.04"
2010 Precipitation: 36.06"

Pennington Gap
August Rainfall: 5.97"
Summer Rainfall: 13.84"
May-August Rain: 19.88"
2010 Precipitation: 36.50"
( 6 days missing during year )

Woolwine
August Rainfall: 6.63"
Summer Rainfall: 13.29"
May-August Rain: 17.49"
2010 Precipitation: 36.56"

Appalachia Lake Water Plant
August Rainfall: 6.66"
Summer Rainfall: 17.75"
May-August Rain: 23.85"
2010 Precipitation: 38.19"

Norton Water Plant
August Rainfall: 7.65"
Summer Rainfall: 15.76"
May-August Rain: 24.36"
2010 Precipitation: 39.13"

Meadows of Dan 5 SW
August Rainfall: 7.69"
Summer Rainfall: 15.13"
May-August Rain: 20.82"
2010 Precipitation: 39.46"
( 11 days missing June-July )

Stuart
August Rainfall: 10.24"
Summer Rainfall: 17.22"
May-August Rain: 22.49"
2010 Precipitation: 39.51"
( 9 days missing June-August )

Robinson Knob of High Knob Massif
August Rainfall: 8.82"
Summer Rainfall: 17.51"
May-August Rain: 23.03"
2010 Precipitation: 39.95" ( M )

Big Stone Gap Water Plant
( South Fork Gorge of High Knob Massif )
August Rainfall: 9.57"
Summer Rainfall: 19.50"
May-August Rain: 25.63"
2010 Precipitation: 40.22"

Big Cherry Dam of High Knob Massif
August Rainfall: 8.91"
Summer Rainfall: 22.71"
May-August Rain: 29.70" ( M )
2010 Precipitation: 48.48" ( M )

( M ) - Denotes missing data during the year from evaporation and losses in snowfall.

High Knob Lake Basin - August 2010

Eastern Tiger Swallowtails ( Papilio glaucus )

West Virginia

Alderson
August Rainfall: 2.88"
Summer Rainfall: 6.28"
May-August Rain: 10.56"
2010 Precipitation: 21.82"

Bluestone Lake
August Rainfall: 2.71"
Summer Rainfall: 6.94"
May-August Rain: 12.11"
2010 Precipitation: 22.85"

Union 3 SSE
August Rainfall: 3.42"
Summer Rainfall: 9.71"
May-August Rain: 13.37"
2010 Precipitation: 22.92"

Lost River
August Rainfall: 2.10"
Summer Rainfall: 7.53"
May-August Rain: 11.26"
2010 Precipitation: 23.06"
( 2 days missing August / 2 days June )

Keyser 2 SSW
August Rainfall: 1.59"
Summer Rainfall: 6.24"
May-August Rain: 11.45"
2010 Precipitation: 23.24"

Martinsburg
August Rainfall: 2.03"
Summer Rainfall: 5.65"
May-August Rain: 10.09"
2010 Precipitation: 24.23"

White Sulphur Springs
August Rainfall: 3.46"
Summer Rainfall: 10.80"
May-August Rain: 14.26"
2010 Precipitation: 25.26"

Bartow 1 S
August Rainfall: 4.85"
Summer Rainfall: 10.80"
May-August Rain: 15.38"
2010 Precipitation: 25.33"
( 3 days missing during year )

Lewisburg 3 N
August Rainfall: 3.40"
Summer Rainfall: 9.92"
May-August Rainfall: 13.65"
2010 Precipitation: 25.58"

Albright
August Rainfall: 1.57"
Summer Rainfall: 10.05"
May-August Rain: 14.56"
2010 Precipitation: 27.07"

Elkins
August Rainfall: 4.86"
Summer Rainfall: 14.49"
May-August Rain: 19.09"
2010 Precipitation: 27.71"

Glenville
August Rainfall: 3.37"
Summer Rainfall: 11.70"
May-August Rain: 16.49"
2010 Precipitation: 28.83"
( 3 days missing during Summer )

Buckeye
August Rainfall: 2.99"
Summer Rainfall: 8.57"
May-August Rain: 16.15"
2010 Precipitation: 28.86"
( 1 day missing in August )

Parkersburg
August Rainfall: 1.96"
Summer Rainfall: 13.64"
May-August Rain: 21.36"
2010 Precipitation: 29.72"

Gassaway
August Rainfall: 2.50"
Summer Rainfall: 12.88"
May-August Rain: 17.51"
2010 Precipitation: 29.76"
( 1 day missing July / 1 day June )

Buckhannon
August Rainfall: 4.53"
Summer Rainfall: 14.40"
May-August Rain: 19.13"
2010 Precipitation: 30.11"
( 1 day missing August / 5 days June )

Marlinton
August Rainfall: 2.97"
Summer Rainfall: 8.93"
May-August Rain: 18.48"
2010 Precipitation: 30.80"

Huntington
August Rainfall: 2.51"
Summer Rainfall: 13.52"
May-August Rain: 20.68"
2010 Precipitation: 31.21"

Bluefield
August Rainfall: 4.22"
Summer Rainfall: 13.79"
May-August Rain: 18.27"
2010 Precipitation: 32.17"

Sutton Lake
August Rainfall: 3.25"
Summer Rainfall: 15.01"
May-August Rain: 19.95"
2010 Precipitation: 32.21"
( 1 day missing August / 1 day July )

Berwind RAWS
( U.S. Forest Service )
August Rainfall: 3.67"
Summer Rainfall: 14.06"
May-August Rain: 20.26"
2010 Precipitation: 33.09"

Beckley
August Rainfall: 2.71"
Summer Rainfall: 12.85"
May-August Rain: 20.32"
2010 Precipitation: 33.17"

McRoss 3 E
August Rainfall: 4.03"
Summer Rainfall: 12.51"
May-August Rain: 18.78"
2010 Precipitation: 33.17"

Bayard
August Rainfall: 2.51"
Summer Rainfall: 11.76"
May-August Rain: 16.03"
2010 Precipitation: 33.81"
( 3 days missing during summer )

Charleston
August Rainfall: 3.30"
Summer Rainfall: 14.59"
May-August Rain: 22.60"
2010 Precipitation: 34.22"

Summersville Lake
August Rainfall: 3.95"
Summer Rainfall: 16.37"
May-August Rain: 22.34"
2010 Precipitation: 35.18"
( 5 days missing during year )

Davis 3 SE
( Canaan Mountain )
August Rainfall: 3.60"
Summer Rainfall: 11.84"
May-August Rain: 16.74"
2010 Precipitation: 35.92"

R.d. Bailey Lake
August Rainfall: 3.07"
Summer Rainfall: 19.17"
May-August Rain: 24.26"
2010 Precipitation: 36.58"
( 1 day missing August / 3 days July )

Hacker Valley
August Rainfall: 3.26"
Summer Rainfall: 17.02"
May-August Rain: 22.58"
2010 Precipitation: 37.89"
( 3 days missing June / 5 days August )

Rock Cave 2 NE
August Rainfall: 5.09"
Summer Rainfall: 17.28"
May-August Rain: 23.25"
2010 Precipitation: 38.46"
( 6 days missing in August )

Terra Alta
August Rainfall: 2.89"
Summer Rainfall: 15.76"
May-August Rain: 21.99"
2010 Precipitation: 39.55"

Snowshoe Mountain
August Rainfall: 5.75"
Summer Rainfall: 17.51"
May-August Rain: 26.40"
2010 Precipitation: 48.22"
( 3 days missing during year )

August 29, 2010
Pike County, Kentucky
Little Boy & Friends - Fishtrap Lake

Kentucky

Paintsville 1 E
August Rainfall: 2.60"
Summer Rainfall: 13.38"
May-August Rain: 17.91"
2010 Precipitation: 27.71"
( 1 day missing in August )

Booneville 12 SW
August Rainfall: 5.75"
Summer Rainfall: 12.64"
May-August Rain: 17.17"
2010 Precipitation: 28.30"

Charley 2 SW
August Rainfall: 3.33"
Summer Rainfall: 14.10"
May-August Rain: 19.11"
2010 Precipitation: 28.80"

Lexington

August Rainfall: 0.58"

Summer Rainfall: 11.23"

May-August Rain: 21.18"

2010 Precipitation: 29.24"

Carr Fork Lake
August Rainfall: 4.61"
Summer Rainfall: 13.14"
May-August Rain: 18.24"
2010 Precipitation: 30.05"
( 5 missing days during year )

London

August Rainfall: 6.03"

Summer Rainfall: 14.48"

May-August Rain: 19.97"

2010 Precipitation: 32.74"

Jackson

August Rainfall: 3.51"

Summer Rainfall: 12.45"

May-August Rain: 20.37"

2010 Precipitation: 32.79"

Skyline 1 SE
August Rainfall: 4.80"
Summer Rainfall: 13.69"
May-August Rain: 20.65"
2010 Precipitation: 32.88"

Buckhorn Lake State Park

August Rainfall: 7.92"

Summer Rainfall: 16.10"

May-August Rain: 20.21"

2010 Precipitation: 33.33"

Barbourville
August Rainfall: 2.33"
Summer Rainfall: 11.33"
May-August Rain: 16.27"
2010 Precipitation: 33.36"

Hazard Water Works
August Rainfall: 6.98"
Summer Rainfall: 17.97"
May-August Rain: 24.06"
2010 Precipitation: 35.99"
( 3 days missing during year )

Oneida
August Rainfall: 9.69"
Summer Rainfall: 19.63"
May-August Rain: 25.18"
2010 Precipitation: 38.46"

Stearns 2 S
August Rainfall: 7.80"
Summer Rainfall: 19.69"
May-August Rain: 27.11"
2010 Precipitation: 40.94"

August 29, 2010
Pine Mountain - SE Kentucky
Nature Scene Along Little Shepherd Trail

Photograph by Roddy Addington - © All Rights Reserved.

Tennessee

Tri-Cities
August Rainfall: 6.26"
Summer Rainfall: 10.80"
May-August Rain: 13.38"
2010 Precipitation: 23.50"

Kingsport
August Rainfall: 6.93"
Summer Rainfall: 12.21"
May-August Rain: 16.02"
2010 Precipitation: 26.29"
( 3 days missing during summer )

Newport 1 NW
August Rainfall: 4.54"
Summer Rainfall: 11.75"
May-August Rain: 16.68"
2010 Precipitation: 26.65"

Knoxville
August Rainfall: 2.80"
Summer Rainfall: 9.94"
May-August Rain: 14.16"
2010 Precipitation: 28.54"

Chattanooga
August Rainfall: 3.05"
Summer Rainfall: 7.91"
May-August Rain: 13.29"
2010 Precipitation: 29.04"

Pikeville
August Rainfall: 1.54"
Summer Rainfall: 8.84"
May-August Rain: 13.27"
2010 Precipitation: 29.25"

Tazewell
August Rainfall: 5.75"
Summer Rainfall: 14.60"
May-August Rain: 21.75"
2010 Precipitation: 36.55"

Lancing 6 NW
August Rainfall: 7.02"
Summer Rainfall: 15.79"
May-August Rain: 22.71"
2010 Precipitation: 38.94"

Monterey
August Rainfall: 6.04"
Summer Rainfall: 15.58"
May-August Rain: 23.48"
2010 Precipitation: 42.04"

Norris
August Rainfall: 6.09"
Summer Rainfall: 16.43"
May-August Rain: 24.99"
2010 Precipitation: 42.62"
( 1 day missing August / 1 day July )

Monteagle
August Rainfall: 7.07"
Summer Rainfall: 16.32"
May-August Rain: 21.04"
2010 Precipitation: 43.22"

Mount LeConte
August Rainfall: 6.64"
Summer Rainfall: 24.06"
May-August Rain: 30.79"
2010 Precipitation: 53.59"
( 1 day missing in July )

High Knob Lake Basin

Mushrooms Galore - August 2010

North Carolina

Raleigh-Durham

August Rainfall: 3.06"

Summer Rainfall: 8.06"

May-August Rain: 13.06"

2010 Precipitation: 24.15"

Charlotte

August Rainfall: 4.75"

Summer Rainfall: 10.12"

May-August Rain: 13.49"

2010 Precipitation: 27.97"

Asheville

August Rainfall: 3.47"

Summer Rainfall: 8.76"

May-August Rain: 13.65"

2010 Precipitation: 30.42"

Hickory

August Rainfall: 3.34"

Summer Rainfall: 10.29"

May-August Rain: 13.70"

2010 Precipitation: 30.58"

Jefferson 2 E

August Rainfall: 5.30"

Summer Rainfall: 9.19"

May-August Rain: 15.05"

2010 Precipitation: 31.50"

( 6 days missing during summer )

Spruce Pine 2 NE

August Rainfall: 6.95"

Summer Rainfall: 14.89"

May-August Rain: 18.08"

2010 Precipitation: 33.06"

Beech Mountain

August Rainfall: 4.67"

Summer Rainfall: 12.28"

May-August Rain: 15.79"

2010 Precipitation: 34.31"

Boone 1 SE
August Rainfall: 5.68"
Summer Rainfall: 11.31"
May-August Rain: 16.67"
2010 Precipitation: 36.73"

Transou

August Rainfall: 7.59"

Summer Rainfall: 18.64"

May-August Rain: 22.46"

2010 Precipitation: 41.40"

Mount Mitchell

August Rainfall: 3.95"

Summer Rainfall: 11.57"

May-August Rain: 16.56"

2010 Precipitation: 44.92"

( 1 day missing in July & 1 day in August )

Grandfather Mountain

August Rainfall: 9.47"

Summer Rainfall: 16.40"

May-August Rain: 20.87"

2010 Precipitation: 49.60"

[ Note: Precipitation may or may not have occurred at any site listed in the states above with missing days ].

Morning Inversion - August 31, 2010

Interior Ridges in Powell Valley of HKL

For a brief review of Summer 2009 please reference:

Wet Summer Across The High Knob Landform In 2009

Climatology of September

Historic Temperatures

High Knob Lake Basin
Fungi Flourish In Late Summer 2010

The dawn of September marks the beginning of meteorological autumn, with weather changes that typically become increasingly pronounced as the month passes and summer fades.

September often brings the first frost of the new cold season to mid-upper elevations, as early colors of autumn begin to decorate the High Knob highcountry.

For a review of September 2009 reference:

September 2009 Generates Wetness & Color

In fact, it can get down right COLD

during some mornings!

Top Ten Coldest September Nights On Record

Wise 1 SE and Wise 3 E

Elevation: 2549 to 2560 feet

Record Period: 1955 to 2009

31 degrees....September 21, 1962

31 degrees...September 23, 1967

31 degrees...September 30, 1967

32 degrees...September 24, 1989

32 degrees...September 29, 1969

33 degrees...September 14, 1964

33 degrees....September 16, 1961

33 degrees...September 25, 1967

34 degrees...September 11, 1964

34 degrees...September 15, 1964

Coldest temperatures are typically observed along the highest ridges, and within mid to upper elevation basins subjected to cold air drainage.

Top Ten Coldest September Nights On Record

Burkes Garden Basin

Elevation: 3068 to 3300 feet

Record Period: 1896 to 2009

21 degrees...September 24, 1983

24 degrees...September 29, 1942

25 degrees...September 18, 1943

25 degrees...September 21, 1962

25 degrees...September 25, 1903

25 degrees...September 30, 1908

26 degrees...September 19, 1929

26 degrees...September 20, 1916

26 degrees...September 22, 1918

27 degrees.....September 6, 1924

While the first true cold front of Autumn 2010 looks to arrive in time for the Labor Day weekend as Hurricane Earl helps reinforce an upper trough digging south across the Great Lakes, the first few days of the month will feature large day to night temperature spreads as subsidence around Earl dries the air over the southern Appalachians.

[ Setting the stage for cool nights in mid-upper elevation valleys and unseasonably warm days ].

Western Atlantic Ocean

1020 hours on August 29, 2010

Danielle ( top ) and Earl ( bottom )

Imagery Courtesy of NASA

[ Feathery outflow from Hurricane Danielle is seen as she pulls away from North America above, with thin cloud filaments connecting with developing Hurricane Earl in the Caribbean ].

September is climatologically the peak of Atlantic hurricane activity, with subsidence induced compressional warming a feature that builds late season surges of heat around the peripheries of these great, warm core monsters.

Top Ten Hottest September Days On Record

Wise 1 SE and Wise 3 E

Elevation: 2549 to 2560 feet

Record Period: 1955 to 2009

90 degrees.....September 1, 1993

90 degrees...September 14, 1998

89 degrees.....September 2, 1957

89 degrees.....September 3, 1999

89 degrees.....September 5, 1975

89 degrees.....September 7, 1990

89 degrees...September 10, 1983

89 degrees...September 13, 1998

88 degrees.....September 4, 1999

88 degrees...September 15, 1998

[ Hurricane Emily made her closest, curving approach to the Outer Banks of North Carolina on September 1, 1993 in correlation to a 90 degree MAX along the western Appalachians in Wise ].

110 air miles NE of San Juan, Puerto Rico

Lat 19.3 degrees North / Long 64.7 degrees West

Hurricane Earl - August 30, 2010

http://earthobservatory.nasa.gov/IOTD/view.php?id=45597

September Rainfall Linked To

Sub-Tropics & Tropics

Climatology reveals that September rainfall amounts across The High Knob Landform are highly linked, or correlated, to what is happening in lower latitudes, with great variations from one year to the next being common.

[ This correlation generally occurring prior to the larger scale cyclogenesis events which arise with increasing frequency as north to south temperature gradients increase during mid-late autumn and winter ( i.e., the main orographic forcing season ) ].

A review of recent years illustrates this well, with September 2009 featuring 9.00" to 11.00"+ of rainfall across the High Knob Massif as abundant moisture streamed into the southern Appalachians from an atypically active sub-tropical jet stream ( a rather unusual setting for so early in an autumn, with a distinct lack of organized tropical systems ).

High Knob Lake Basin

Swallowtail Butterfly on ( Eupatorium spp. )

September 2008 featured only 2.50" to 3.00"+ of rain across the High Knob Massif area, as an enhanced amount of sinking air ruled between tropical cyclones which tracked both west and east of the southern Appalachians.

[ IKE being the big ticket storm of September 2008 that pounded a corridor from Houston to Chicago with flooding rains, while causing damaging winds of 70-80+ miles per hour across northern Kentucky and the Ohio Valley ].

September 2007 was analogous, as tropical cyclone tracks stayed well east and south of the southern Appalachians with only 2.00" to 3.00" of rainfall across the High Knob Massif.

High Knob Massif

Pipevine Swallowtail ( Battus philenor )

Working Brilliant Milkweed ( Asclepias spp. )

September 2006 was much different, as a combination of remnant tropical moisture and several deep, moist southwesterly flow frontal events generated 7.00" to 10.00"+ of rain across the High Knob Massif.

September 2004 was a big ditto, to an even greater degree, as remnants of hurricanes Frances, Ivan, and Jeanne all spread rich, tropical moisture across the southern Appalachians. Rainfall totals reached 17.00"+ within Big Cherry Basin of the High Knob Massif.

So a review of only a few years illustrates well how September conditions are impacted by what's going on in the sub-tropics and tropics, with September 2010 being to date ruled by sinking air adjacent to the Atlantic "hurricane highway."

[ In general, as heavy 1.50"-3.00"+ rainfall amounts from the remnants of Hermine soaked southwestern portions of the HKL during September 11-12, from western Lee County & Cumberland Gap National Historical Park into the I-75 corridor of northern Tennessee and southern Kentucky ].

( Updated: September 15, 2010 )

Mid-September Climate Update

High Knob Lake Special Biological Area

Unusual Mushroom Form - High Knob Massif

The first half of September 2010 has featured near average temps within the High Knob Massif area, with unseasonably warm days being offset by cool nights.

September 1-15, 2010

City of Norton - Elevation 2141 feet

Average Daily MAX: 78.1 degrees

Average Daily MIN: 46.4 degrees

MEAN: 62.2 degrees
Rainfall: 1.50"
( 40.63" in 2011 )

The High Knob Landform

Thursday, October 7, 2010

October 2010: Majestic Opening To Autumn

Tuesday, October 5, 2010

September 2010: Fall Opens Drier & Warmer

Thursday, September 2, 2010

Summer 2010: Wet & Humid In The HKL

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Thursday, October 7, 2010

October 2010: Majestic Opening To Autumn

Tuesday, October 5, 2010

September 2010: Fall Opens Drier & Warmer

Thursday, September 2, 2010

Summer 2010: Wet & Humid In The HKL

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