Saturday, August 11, 2012

A WET Opening To August 2012


August 7, 2012
View From Lonesome Pine Airport
Looking To High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

The High Knob Landform

Framed by cloud capped forests of the High Knob Massif, a field of late summer wildflowers is bathed in heavenly light as sunset approaches Lonesome Pine Airport in Wise County, Virginia.

August 7, 2012
Lonesome Pine Airport - Elevation 2684 feet
Cloud Capped Forests of High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

Rod Addington Photography

August 7, 2012
Heavenly Rays of Sunlight
Photograph by Roddy Addington - © All Rights Reserved.

Special Edition: Colors Of Heaven's Glory

Nestled against northern slopes of the sprawling High Knob Massif, where flowing air is often forced to rise & converge, the City of Norton has received measurable rain on 32 of the past 41 days.  
[ For the period ending on August 11, 2012 ].

Updated - August 20, 2012
( Northern Base of High Knob Massif )
August 2012 Rainfall Days
City of Norton Water Plant
Observers - Water Plant Staff
Elevation 2342 feet

( Daily Amounts Ending At 9 AM )

8/1:  1.62"
8/2:  0.07"

8/4:  0.40"
8/5: 0.02"
8/6: 1.55"
8/7:  0.35"
8/8: 0.06"
8/9:  0.01"
8/10: 1.34"
8/11: 0.80"

8/15: 0.03"
8/16: 0.40"

8/18: 0.90"
8/19: 0.02"
8/20: 0.50"

*August 1-20 Total: 8.07"

Total Since July 1: 18.77"

Total Since June 1: 21.56"

2012 Total: 48.82"
( As of August 20, 2012 )

Total Since January 1, 2011: 125.28"

*Doppler radar and other rain gauges show a general 6.00" to 8.00" of rainfall across the City of Norton during the first 10 days of August ( ending AM of August 11 ).  This includes Flag Rock Recreation Area and Benges Basin of the Norton Reservoir system.

August 7, 2012
Looking West - Lonesome Pine Airport
Glory Of Heavenly Light Near Sunset
Photograph by Roddy Addington - © All Rights Reserved.

A general 15.00" to 25.00" of summer rain has fallen in the High Knob Massif area during the June 1 to August 11 period of 2012.

Updated - August 20, 2012
August 2012 Rainfall Days
Robinson Knob of High Knob Massif
Observers - Otis & Nancy Ward
Elevation 3240 feet

( Daily Amounts Ending At 8 AM )

8/1:  1.14"
8/2:  0.03"

8/4:  0.20"
8/5:  0.35"
8/6:  0.79"
8/7:  1.34"
8/8:  0.54"

8/10:  0.40"
8/11: 0.26"

8/15: 0.02"
8/16: 0.18"

8/18: 0.34"
8/19: 0.03"
8/20: 1.00"

August 1-20 Total: 6.62"

Total Since July 1: 20.80"

Total Since June 1: 23.87"

2012 Total: 49.03" ( M )
( As of August 20, 2012 )

Total Since January 1, 2011: 130.17" ( M )

( M ) - Indicates missing moisture in deeper falls of winter snow.

Despite again missing heaviest rains this summer, the total at Big Cherry Dam since the beginning of January 2011 has been more than 128.00" when factoring in the moisture losses ( 2.04" so far in 2012 ) on the 4-inch diameter NWS gauge.

August 7, 2012
Looking Into The Heavens
Photograph by Roddy Addington - © All Rights Reserved.

A huge precipitation gradient has again developed across Virginia in 2012, as well documented by this website in recent years, with extreme differences since the beginning of 2011 varying from less than 60.00" in drier locations of the Old Dominion to more than 130.00" of total precipitation in wetter portions of the High Knob Massif ( a 70.00"+ variation in just over 19 months ).


Precipitation Statistics
Virginia & District of Columbia
( Totals As Of August 12, 2012 )





Washington National Airport
June 1-August 12 Rainfall: 5.93"
2012 Precipitation Total: 16.67"
( 63.56" since January 1, 2011 )

Washington Dulles Airport
June 1-August 12 Rainfall: 5.82"
2012 Precipitation: 18.63"
( 64.83" since January 1, 2011 )

Danville
June 1-August 12 Rainfall: 6.78"
2012 Precipitation: 19.32"
( 58.33" since January 1, 2011 )

Lynchburg
June 1-August 12 Rainfall: 5.37"
2012 Precipitation: 20.78"
( 59.75" since January 1, 2011 )

Richmond
June 1-August 12 Rainfall: 10.63"
2012 Precipitation: 22.94"
( 70.48" since January 1, 2011 )

Roanoke
June 1-August 12 Rainfall: 8.51"
2012 Precipitation: 23.00"
( 68.03" since January 1, 2011 )

Charlottesville
June 1-August 12 Rainfall: 9.46"
2012 Precipitation: 23.54"

Christiansburg
June 1-August 10 Rainfall: 6.30"
2012 Precipitation: 23.94"

Wallops Island
June 1-August 12 Rainfall: 7.70"
2012 Precipitation: 24.01"
( 60.24" since January 1, 2011 )

Galax WTP
June 1-August 12 Rainfall: 8.17"
2012 Precipitation: 25.31"

Gathright Dam
June 1-August 12 Rainfall: 8.44"
2012 Precipitation: 26.00"

Blacksburg
June 1-August 12 Rainfall: 8.44"
2012 Precipitation: 26.47"
( 70.15" since January 1, 2011 )

Hot Springs
June 1-August 12 Rainfall: 9.46"
2012 Precipitation: 27.59"

Covington FP
June 1-August 12 Rainfall: 11.18"
2012 Precipitation: 28.59"

Trout Dale 3 SSE
June 1-August 12 Rainfall: 10.90"
2012 Precipitation: 30.19"

Clintwood 1 W
June 1-August 12 Rainfall: 11.17"
2012 Precipitation: 30.35"
( 91.33" since January 1, 2011 )

Nora 4 SSE
June 1-August 12 Rainfall: 9.98"
2012 Precipitation: 30.37"
( 87.80" since January 1, 2011 )

Burkes Garden
June 1-August 12 Rainfall: 7.96"
2012 Precipitation: 31.27"
( 81.96" since January 1, 2011 )

Grundy
June 1-August 12 Rainfall: 14.76"
2012 Precipitation: 31.35"

Wytheville 1 S
June 1-August 12 Rainfall: 9.87"
2012 Precipitation: 32.02"
( 73.52" since January 1, 2011 )

Saltville 1 N
June 1-August 12 Rainfall: 11.68"
2012 Precipitation: 32.50"

Lebanon
June 1-August 12 Rainfall: 12.69"
2012 Precipitation: 33.20"

Meadows of Dan 5 SW
June 1-August 12 Rainfall: 12.02"
2012 Precipitation: 37.46"
( 106.35" since January 1, 2011 )

Richlands
June 1-August 12 Rainfall: 15.92"
2012 Precipitation: 37.87"

Appalachia Lake Water Plant
June 1-August 12 Rainfall: 18.29"
2012 Precipitation: 42.23"
( 110.12" since January 1, 2011 )

Coeburn Filter Plant
June 1-August 12 Rainfall: 17.48"
2012 Precipitation: 42.48"
( 110.29" since January 1, 2011 )

Norton Water Plant
June 1-August 12 Rainfall: 19.71"
2012 Precipitation: 46.97"
( 123.43" since January 1, 2011 )

Robinson Knob of High Knob Massif
June 1-August 12 Rainfall: 22.30"
2012 Precipitation: 47.46" ( M )
( 128.60" since January 1, 2011 ) ( M )

( M ) - Indicates missing moisture in deeper falls of winter snow.

August 7, 2012
Lonesome Pine Airport - Wise Plateau
Looking West Into Heavenly Light & Rising Air
Photograph by Roddy Addington - © All Rights Reserved.


Major Late Summer
Pattern Change
( Greenland Blocking )

August 7, 2012
Cumberland Overthrust Block
Beams Of Sunlight Above The Wise Plateau
Photograph by Roddy Addington - © All Rights Reserved.

Summer 2012 has been a changeable beast, opening cool and damp in early June before giving way to dryness and all-time record heat by late June.  A literal monsoon followed to dominate the heart of summer with excessive rainfall and high humidity levels throughout July and the first ten days of August.  Soaking wetness!

Then, suddenly, a gush of cooler air was felt once again during the weekend of August 11-12 as low temperatures dipped into the 40s amid high mountain valleys from the High Knob Massif to Burkes Garden, with 50s across the lower terrain.

The culprit of this pattern flip could easily be seen on upper air charts for August 14, with a large region of above average 500 MB heights across Greenland in a classic blocking position that is notorious for aiding the development of below average temperatures across the eastern USA during the cold season.

European Model ( ECMWF ) Analysis
500 MB Height Anomaly At 8 AM - August 14, 2012

Forecasted 500 MB Anomalies At 8 AM - August 17

Forecasted 500 MB Anomalies At 8 AM - August 19 

Forecasted height anomalies become more extreme during the 3-5 day period ahead, from August 14, such that the next approaching Canadian cold front will be more vigorous with heavier rain potential ( booming storms ) and a renewed surge of unseasonably cool, late summer air.

( Follow Up Notes )
A large MCS developed in the Mississippi Valley during August 17 with widespread debris cloudiness keeping the local atmosphere relatively stable into August 18.  

Strong convection developed along northern slopes of the High Knob Massif late on August 18 with rainfall totals of 0.50" to 1.00"+ from the City of Norton into portions of Pickem Mountain, Clear Creek Basin, Machine Creek Basin, and the highcountry communities of High Chaparral, Robinson Knob, and Flat Gap.

August 12, 2012
The Glorious Milky Way Galaxy
Photograph by Roddy Addington - © All Rights Reserved.


Climate Statistics
Mid-August 2012
( August 1-15 Period )

Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 80.3 degrees
Average Daily MIN: 61.1 degrees
MEAN: 70.7 degrees
August 1-15 Rainfall: 3.17"
2012 Precipitation: 30.41"

City of Norton - Elevation 2141 feet
Average Daily MAX: 79.2 degrees
Average Daily MIN: 58.3 degrees
MEAN: 68.8 degrees
August 1-11 Rainfall: 6.22"
2012 Precipitation: 46.97"

Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 77.2 degrees
Average Daily MIN: 62.1 degrees
MEAN: 69.6 degrees
August 1-15 Rainfall: 2.93"
2012 Precipitation: 30.37"

In the High Knob highcountry the first half of August generated mean daily maximums around 70 degrees at highest elevations ( with temps during August 10-15 not getting above the 60s ) and mean nightly minimums in the mid-upper 50s.

A warm start being tempered by recent cooling.

Rainfall remained abundant with a general 3.50" to 6.50"+ across the massif area during the first half of August ( rain fell on 12 out of 15 days in some places ).

Wes Ward measured an additional 1.33" of rain in the official NWS gauge at the Norton Water Plant through morning hours of August 18, boosting the August 1-18 rainfall tally to 7.55" ( locally 8.00" to 9.00" has fallen upon the High Knob Massif ). 

August 12, 2012
"A Shooting Star" - Annual Perseids Meteor Show
Photograph by Roddy Addington - © All Rights Reserved.

A welcomed break came just in time to generate a starry, cool night for the annual Perseids Meteor Show with temperatures dropping into the 40s to lower 50s amid higher mountain valleys during August 12 ( elevations above 2000-3000 feet ).

August 12, 2012
Colorful Tail of Meteor 
Photograph by Roddy Addington - © All Rights Reserved.


Adding To Heaven's Glory
Majesty Of July-August 2012

August 13, 2012
North of The Wise Plateau
Magnificent Sunset From Boggs Hill
Photograph by Roddy Addington - © All Rights Reserved.

New July-August 2012 Additions
Gallery Of Heavenly Photographs
Special Edition: Colors Of Heaven's Glory

The talented, truly gifted photographers of this website have once again come through with an array of simply awesome July and August scenes, adding to the already impressive gallery collection found at the above link.

August 13, 2012
Flaming Colors Of An August Sunset
Photograph by Roddy Addington - © All Rights Reserved.

Many sunrises & sunsets have been spectacular, with heavenly light and the always interesting mixture of mountain wave and synoptic cloud forms.  Purely magical.

July 28, 2012
Flaming Colors Of A Morning Sunrise
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Photograph Thoughts...
 "The rain of the night left us with a colorful sunrise."

July 19, 2012
Silver Leaf Community
Vivid Cloud To Ground Lightning Strike
Photograph by Harold L. Jerrell - © All Rights Reserved.

Many thunderstorms during the summer generated vivid lightning!

July 19, 2012
Powell River Basin
Lightning Circuits In The Sky
Photograph by Harold L. Jerrell - © All Rights Reserved.

July 19, 2012
Vivid Lightning Circuit
Photograph by Harold L. Jerrell - © All Rights Reserved.

Thursday, August 2, 2012

July 2012 Summary - Very WET & MUGGY


July 30, 2012
Majesty Of Evening Thunderheads
Photograph by Wayne Riner - © All Rights Reserved.


Wayne Riner Photograph Thoughts...
It seems that every evening, the heat of the day develops into thunderstorms. From the ridges the view is exceptional and reminds me of the lines written by Joni Mitchell:

I've looked at clouds from both sides now
From up and down, and still somehow
It's cloud illusions I recall
I really don't know clouds at all.

July 30, 2012
Gibbous Moon Rises Above Thunderheads
Photograph by Wayne Riner - © All Rights Reserved.

Note striations of pilatus clouds waving across bubbling cumulonimbus towers on right side of photograph, indicative of vigorous upward vertical motion!

July 2012 was indeed a month of great extremes, with early summer dryness quickly giving way to WETNESS across the High Knob Landform as majestic cumulonimbus towers soared upward for miles into the heavens nearly every day.

By the very nature of convection, rains are never spread evenly across the landscape during this time of year with often dramatic variations over only short air distances.  This is especially true in mountainous terrain where many factors come into play to trigger and direct the development and trajectories of thunderstorms.

Part of the reason that I have been taking great pains to document much of this July action with more than 1000 Doppler radar base reflectivity frames on the following website links.

Best viewed using Google Chrome & Safari.

Documenting July 2012 
( Work In Progress )




The High Knob Massif area was a focus of heavy action throughout the month with a general 8.00" to 18.00" of July rainfall.

July 2012 Rainfall Days
Robinson Knob of High Knob Massif
Observers - Otis & Nancy Ward
Elevation 3240 feet

( Daily Amounts Ending At 8 AM )

7/2: 0.34"

7/4: 0.48"
7/5: 0.06"
7/6: 0.67"

7/9: 3.45"
7/10: 0.55"
7/11: 0.65"
7/12: 0.28"
7/13: 0.56"
7/14: 0.28"
7/15: 0.42"

7/17: 0.52"

7/19: 0.83"
7/20: 0.43"

7/23: 0.03"
7/24: 0.39"
7/25: 4.24"

7/31 PM: 1.14"

Total: 14.18"
( Through 8 AM July 31 )

Total: 15.23"
( Through Midnight July 31 )

Total Since June 1: 18.30"

2012 Total: 43.55" ( M )

19-Month Total: 124.69" ( M )
( Mean of 6.56" per month )

( M ) - Indicates missing moisture in deeper falls of winter snow. 

This marked the second consecutive July with more than a FOOT of measured rainfall in the Robinson Knob community of the High Knob Massif by my friends Otis & Nancy Ward.

Summer 2011 Gets Even WETTER

This marks the third consecutive summer on the website that I have documented a FOOT or more of rainfall during one or more summer months in the High Knob Landform.

Summer 2010: Wet & Humid In The High Knob Landform

Summer 2011 Opens WET In The High Knob Landform

Northern Scott County, Virginia
White Bluff Drive of Dungannon Area
In Wake of Flash Flooding On July 25, 2012
Courtesy of Carol Sluss - Submitted To WCYB-TV StormTrack5

The wettest city in Virginia continued to live up to its standards during July 2012 with 18 consecutive days of measurable rainfall in the official 8-inch diameter NWS gauge at the Norton Water Plant.

( Northern Base of High Knob Massif )
July 2012 Rainfall Days
City of Norton Water Plant
Observers - Water Plant Staff
Elevation 2342 feet

( Daily Amounts Ending At 9 AM )

7/2: 0.20"

7/4: 0.18"
7/5: 0.02"
7/6: 0.58"

7/9: 0.75"
7/10: 0.75"
7/11: 0.09"
7/12: 0.78"
7/13: 0.62"
7/14: 0.04"
7/15: 0.73"
7/16: 0.06"
7/17: 0.44"
7/18: 1.06"
7/19: 0.63"
7/20: 0.30"
7/21: 0.01"
7/22: 0.32"
7/23: 0.03"
7/24: 0.10"
7/25: 3.00"
7/26: 0.01"

7/31 PM: 1.62"

Total: 10.70"
( Through 9 AM July 31 )

Total: 12.32"
*( Through Midnight July 31 )

Total Since June 1: 15.11"

2012 Total: 42.37"

19-Month Total: 118.83"
( Mean of 6.25" per month )

*Doppler radar and other rain gauges suggested that up to 14.00"+ fell in parts of the City of Norton during July 2012.

The July 9-25 recording period was wettest with 9.62" in the City of Norton and 12.63" in Robinson Knob during 17 days.  Doppler radar suggested that local amounts topped 15.00" during this time in the High Knob Massif area ( nearly 1.00" per day )!

July 25, 2012
Red Jewels In The Woods
Photograph by Wayne Riner - © All Rights Reserved.

An explosion of fungi are on display in wake 
of all this wetness.  

Please reference the Ecology & Biodiversity section of the main High Knob Landform link for 
a sampling of the extraordinary diversity of fungi found amid this ancient mountain landform.

( Scroll to Ecology-Biodiversity and look for Fungi Species )

High Knob Meadow
July 23, 2012 at 2:21 AM
Awesome Beauty of The Milky Way Galaxy
Grant Stanley Photograph - © All Rights Reserved.

Grant Stanley Photography

On a starry July night the magnificent beauty of our Milky Way Galaxy was captured in all its glory by photographer Grant Stanley, shooting from above 4100 feet in lofty High Knob Meadow, where even in reduced light the tall ( rain fed ) tops of Cow Parsnip ( Heracleum maximum ) can be seen in heavenly light.


Climate Statistics
For July 2012

( Lower elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 83.7 degrees
Average Daily MIN: 63.8 degrees
MEAN: 73.8 degrees
Highest Temperature: 92 degrees
Lowest Temperature: 59 degrees
Rainfall: 6.23"
( 6.56" thru Midnight July 31 )
2012 Precipitation: 27.24"

( Northern base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 83.0 degrees
Average Daily MIN: 61.7 degrees
MEAN: 72.4 degrees
Highest Temperature: 92 degrees
Lowest Temperature: 57 degrees
Rainfall: 10.70"
( 12.32" thru Midnight July 31 )
2012 Precipitation: 42.37"

( North of High Knob Massif )
Wise 3 E - Elevation 2549 feet
Average Daily MAX: 81.4 degrees
Average Daily MIN: 64.3 degrees
MEAN: 72.8 degrees
Highest Temperature: 92 degrees
Lowest Temperature: 59 degrees
Rainfall: 10.69"
2012 Precipitation: 33.36"

( Long Ridge of Sandy Ridge )
*Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 80.5 degrees
Average Daily MIN: 66.1 degrees
MEAN: 73.3 degrees
Highest Temperature: 90 degrees
Lowest Temperature: 61 degrees
Rainfall: 4.30"
( 4.37" thru Midnight July 31 )
2012 Precipitation: 27.51"

*Denotes that much of the temperature data for July was recorded with a Davis Pro2 Station due to a lightning strike which required replacement of the NWS MMTS.

In the High Knob highcountry mean July temps varied from 70s by day, with low-mid 70s on upper north slopes and crestlines at highest elevations dominated by clouds, to upper 50s-lower 60s at night ( producing upper 60s to lower 70s monthly means in mid-upper elevations of the very wet High Knob Massif ).

July rainfall totals generally varied from 8.00" 
to 18.00" with ironically, it might seem, the 
Big Cherry Dam measuring point coming in with the least amount as heavy rain cores flanked the lower basin of Big Cherry Lake ( 8.21" of rain was measured into morning hours of July 31, with around 9.00" thru Midnight on July 31 ). 

[ A total of 0.26" of moisture loss was observed at Clintwood 1 W during the month on the NWS 4" gauge measured once weekly verses the 8" NWS gauge measured daily.  This suggested that around 0.30" of loss likely occurred at Big Cherry Dam during July, where rain was measured on 7 days during the month ].

With up to 12.00"+ of rain falling across the mid-upper basin of Big Cherry Lake, with enhanced run-off, the lake gained 55.9 million gallons of water and began flowing over its Dam in wake of the July 25 storm event. The Lake level having been below its spillway for 48 days from June 9 to July 26 ( having dropped 1.5 feet, at its lowest point, to 91% of capacity ).  Big Cherry Dam has been in overflow throughout the remainder of 2012.

Beauty of the Woods ( Amanita jacksonii )
Photograph by Wayne Riner - © All Rights Reserved.

A nice illustration of how rainfall tends to vary in this type of pattern can be found by noting the following July 2012 totals...

Nora 4 SSE on Long Ridge: 4.37"
( Through Midnight July 31 )

Robinson Knob of High Knob Massif: 15.32"
( Through Midnight July 31 )

A 10.95" difference in 14.9 air miles!

These extreme variations in July 2012 remind me of the graphic I created in wake of excessive August 2010 rainfall in the High Knob Massif 
( and just updated with more data ).

Generalized Rainfall Map For August 2010


August 2010 rainfall totals varied from only 1.37" at John W. Flannagan Dam in Dickenson County to as much as 15.00" in the High Knob Massif of northern Scott County.


( High Knob Landform - Clinch River Valley )
Additional July 2012
Rainfall Totals

Silver Leaf: 13.01"
( SE of Rose Hill )

Dungannon: 11.18"

Coeburn Filter Plant: 10.90"

*Big Stone Gap Water Plant: 10.66"
( Mouth of South Fork Gorge )

Downtown Coeburn: 10.52"

*Appalachia Lake Water Plant: 10.41"

Fort Blackmore: 10.41"

Natural Tunnel State Park: 9.49"

*Total through the morning of July 31.


Regional Rainfall Extremes
July 2012

Ohio Valley - Midwest
July 2012 Generalized Rainfall Variations

This set of graphics reveal the generalized rainfall extremes observed during the month of July 2012, with actual local variations being even greater than indicated by these Doppler radar and NWS Cooperative rain gauge composite charts.

The above graphic suggests some places had less than 0.50" of rain during the month of July, with a closer inspection from the Midwest Regional Climate Center showing just how widespread those conditions have been during the past 30-days ( ending August 3 ).


A few of the drier rain gauge totals included:

Illinois Rainfall Totals
July 2012

Paris: 0.02"

Charleston: 0.08"

Havana: 0.20"

Danville: 0.37"

Simply incredible dryness when combined 
with extreme HEAT.

There were also some very dry places in Virginia during July, especially from the New River and Roanoke valleys into northeastern portions of the Old Dominion.

Centered On The State of Virginia
July 2012 Generalized Rainfall Variations

Virginia Rainfall Totals
July 2012

South Boston: 1.90"

Christiansburg: 1.96"

Woodstock 2 NE: 2.27"

Washington Dulles Airport: 2.43"
( District of Columbia )

Danville: 2.57"

Staffordsville 3 ENE: 2.59"

Lynchburg: 2.73"

Brookneal: 2.82"

Roanoke: 3.14"

Wallops Island: 3.46"

Hot Springs: 3.76"

Blacksburg: 3.87"
( 2.58" thru AM July 31 )

Pulaski: 3.97"

Rocky Mount: 4.29"

Charlottesville: 4.34"

Glasgow 1 SE: 4.31"

Norfolk: 4.81"

Richmond: 5.29"

Meadows of Dan 5 SW: 5.52"

Burkes Garden: 5.61"

Saltville 1 N: 5.76"

Wytheville 1 S: 6.58"

Trout Dale 3 SSE: 7.35"

Grundy: 7.87"

Stuart: 7.97"

Lebanon: 9.39"
( 9.46" through Midnight July 31 )

Richlands: 9.05"
( 11.35" through Midnight July 31 )

Centered On Blacksburg NWSFO Area
July 2012 Generalized Rainfall Variations

A major rainfall gradient was observed across Virginia with excessive rains clustered along and west to northwest of the Clinch & Holston river valleys of the Upper Tennessee River Basin 
( the core of maximum rain totals being centered across the High Knob Massif ).

Centered On Morristown, Tn., NWSFO Area
July 2012 Generalized Rainfall Variations

Excessive rains extended south-southeast from the High Knob Massif into the Great Valley of extreme northern Tennessee where TRI ( Tri-Cities Airport ) had its wettest month of ALL-TIME.

Special Weather Statement On Record Event
All-Time Monthly Rainfall Record Broken

"The monthly rainfall total for July at the Tri-Cities airport was 12.70 inches. This amount breaks the previous monthly record for July at the Tri-Cities airport of 9.73 inches set back in July 1949. In addition, this amount also breaks the all-time monthly rainfall record for the Tri-Cities airport of 11.34 inches set back in August 2003."

This marked only the second time that TRI reached into double digits during a month ( the previous being August 2003 ).

Records at TRI date back in unbroken fashion to October 1937 and in a periodic manner to February 1894.


Climate Of The 1930s
Decade Of The Dust Bowl


Given the widespread growing season drought of 2012, and the intense drought anchored over Texas in 2011, I thought it might be interesting to look back in time to see what weather conditions were like in the High Knob Landform during the infamous Dust Bowl.

Is it accidental that Summer 2011 and Summer 2012 have both been very wet across this ancient mountain landscape of the High Knob Landform, or is there a bigger connection to dryness in the USA heartland?

The infamous Dust Bowl was not a single, consecutive period of drought but instead came in waves of intense dryness that actually stretched from the late 1920s into the early 1940s.  It was a decadal event centered upon the 1930s in which consecutive waves of extreme drought came so rapidly in succession that regions impacted could not recover between major events.



[ Note that Palmer Drought Index ( PDI ) graphics are based upon climate divisions and may not accurately reflect conditions experienced within any local area or landform ].

Weather data was locally scarce during the Dust Bowl period with Dante, in extreme northwestern Russell County, being the closest station to the Virginia section of the High Knob Landform to have complete data through the 1928-1941 period.

( 1928-1941 )
Total Annual Precipitation
Dante, Virginia
Elevation 2000 feet

1928: 49.97"
1929: 58.29"
1930: 41.47"
1931: 48.30"
1932: 56.69"
1933: 43.39"
1934: 49.07"
1935: 55.44"
1936: 54.02"
1937: 53.53"
1938: 54.25"
1939: 40.74"
1940: 40.27"
1941: 38.14"

1928-1941 Mean: 48.83"

1930-1939 Mean: 49.69"

24-Year Mean: 50.82"

The Dante recording site was located some 9 air miles northeast of the eastern end of the High Knob Massif.

Pennington Gap of northeastern Lee County started recording in 1931, with the first year of complete data being 1932.

( 1932-1941 )
Total Annual Precipitation
Pennington Gap, Virginia
Elevation 1386 feet

1932: 52.43"
1933: 41.56"
1934: 43.43"
1935: 55.15"
1936: 57.61"
1937: 53.02"
1938: 50.29"
1939: 45.07"
1940: 43.34"
1941: 40.49"

1932-1941 Mean: 48.24"

1932-1939 Mean: 49.82"

66-Year Mean: 49.23" ( M )
( July 9, 1931 to November 14, 2010 )

The Pennington Gap recording site is located upon the Powell River Valley floor amid the calcareous core of the High Knob Landform ( around 11 air miles W-WSW of the southwestern end of the High Knob Massif ).

( M ) - Indicates some missing data, including entire months and years, during the observation period ( not part of mean ).

Burkes Garden has one of the longest observation periods in southwestern Virginia and recorded the following during the Dust Bowl era.

( 1928-1941 )
Total Annual Precipitation
Burkes Garden, Virginia
Elevation 3250 feet

1928: 38.91"
1929: 41.98"
1930: 27.61"
1931: 39.25"
1932: 57.75"
1933: 43.03"
1934: 50.86"
1935: 55.61"
1936: 52.25"
1937: 46.35"
1938: 48.00"
1939: 36.54"
1940: 39.21"
1941: 37.49"

1928-1941 Mean: 43.92"

1930-1939 Mean: 45.72"

Long-Term Mean: 45.24"
( March 11, 1896 to April 30, 2012 )

Based upon these data points the decade of the 1930s generated near average precipitation in southwest Virginia, with the driest period being 1939-1941 when all three sites had much below average totals ( Dante was 11.08" below average per year ).

1939 to 1941 Recording Period
Mean Precipitation / Departure From Average

Dante: 39.72" / -11.08"

Pennington Gap: 42.97" / -6.26"

Burkes Garden: 37.75" / -7.49"

It is interesting to note that despite this abnormally dry period, there were locally excessive summer rains in the area with the following recorded along the Virginia-Kentucky border.

#( Near Harlan County-Wise County line )
Black Mountain, Kentucky
Elevation 4000 feet

July 1940: 10.87"

July 1941" 17.13"

#This was 5 air miles from NW flank of High Knob Landform.

The driest single year during the 1928-1941 period for many locations was 1930.  This is exemplified in southwestern Virginia by Burkes Garden where only 27.41" of precipitation were measured.  Closer to the High Knob Massif, by contrast, 41.47" was measured that year in Dante.

Southwestern Mountain Division of Virginia
Mean Monthly Precipitation For 1928-1941

The RED line illustrates the monthly values averaged for all available recording sites across southwestern Virginia during the 1928-1941 period verses the GREEN line that represents "normal" precipitation.  Note that 1930 and 1939-41 stand out as being the driest years of the Dust Bowl era in this region.

 A spike in mean amounts during August 1940 was due to the landfall of an Atlantic hurricane which brought excessive rains to Virginia, especially along and east of the Blue Ridge province.

Although an automated TVA rain gauge was installed near High Knob in the mid-late 1930s, a significant amount of missing data occurred along with wind driven rain gauge undercatches to make annual totals incomplete. 

Enough data is available from southwestern Virginia to suggest that mean precipitation would have been relatively abundant, especially when considering that sites like the City of Norton average 8.00"+ more precip per year than Pennington Gap ( * ). 

*Pennington Gap averaged only 0.31" less than Dante
during the 1932-1941 recording period.

[ The precipitation difference between Pennington Gap and Norton tends to be least during the driest years, as illustrated later, since there are fewer weather events for orographic enhancement of precipitation in extended periods of drought ].

During the 2009-2011 period, as previously highlighted on this website, Big Cherry Dam in 
the High Knob Massif averaged 24.70" more precipitation per year than Burkes Garden despite up to 3.50" of moisture losses per year. This implies that the 45.72" mean observed in Burkes Garden during the 1930s would have been MUCH greater in the High Knob Massif ( with less than 10% of the 1928-1941 period likely spent in what the PDI would consider severe-extreme drought ).

The bottom line being that local data which is available, and the now known climatology of this area, in combination with the "big picture" pattern suggests that the Dust Bowl era was not very dusty amid the High Knob Massif and across much of its Upper Tennessee River Basin.

[ Clouds of dust were transported across the area at times during this period by winds blowing from core regions of drought centered amid the USA heartland ].


The Past Month
Palmer Drought Index Maps
( June 30 to August 11 of 2012 )

While the PDI can be good to illustrate the "big" picture it can be way off on local conditions as illustrated by this current series of maps in which local wetness should have been indicated by green colorations on maps from July 14 to August 11.

June 30, 2012

July 7, 2012

July 14, 2012

July 21, 2012

July 28, 2012

August 4, 2012

August 11, 2012

On a very local scale there were some places ( especially north of the High Knob Landform in Dickenson County ) with near to drier than normal soil moisture during July ( e.g., 4.37" of rain on Long Ridge of Sandy Ridge during July ) even as many places developed excessive wetness.

In reality, having noted the above, these next two maps are absurd given numerous high water cases observed during the past 30 days across this area 
( where NO more rain is needed right now and this summer is by no means in the lowest classes for dryness on the PDI ).

Additional Precipitation Needed

PDI Rank By States & Nation


The Big Picture
Major Past Droughts

With obvious flaws of the Palmer Drought Index 
( PDI ) noted above, it can still be used to look at the big picture across the USA during major local drought years in recent decades.

Drought of 1988

1988 Total Precipitation

Appalachia Lake Water Plant: 45.79"

City of Norton Water Plant: 45.75"

Pennington Gap Water Plant: 42.95"

Burkes Garden: 33.88"


Drought of 1999 
( Near Climax Period - September 25, 1999 )

1999 Total Precipitation

Appalachia Lake Water Plant: 46.81"

City of Norton Water Plant: 42.44"

Pennington Gap Water Plant: 41.61"

Burkes Garden: 32.47"


Drought of 2007
( Near Climax Period - October 13, 2007 )

2007 Total Precipitation

*Appalachia Lake Water Plant: 40.62"

*City of Norton Water Plant: 39.69"

Pennington Gap Water Plant: 37.97"

Burkes Garden: 37.41"

*Driest year on record.

It is possible that 1930 may have rivaled 2007 for dryness in the High Knob Massif area, where driest years observed during the past 30 years averaged 40.00" to 50.00" of total precipitation.

( By comparison, as of 9 AM on August 6, there had been 44.86" of total precipitation measured at the Water Plant in the City of Norton during 2012 ).

An outstanding feature of all three of these major local drought events was near to above average wetness ( soil moisture and PDI values ) through a large portion of the central USA.  Development of such conditions eliminates "ring of fire" convection observed last summer ( map below ) and this summer since the crushing heat dome is set up over the southern Appalachians with its dry feedback working to hinder rain production.

August 6, 2011
Heat Dome Anchored Over Texas

In the big picture, from a basin perspective, there tends to be less drought in the Tennessee River Basin than in the Ohio River Basin.



Droughts in the Tennessee River Basin can become more aerially extensive in nature when they occur ( main watersheds in the headwaters of the basin, like the High Knob Massif area, being least impacted over time ).


Rainfall Update
First Week of August 2012

July 25, 2012
Long Ridge of Tennessee Valley Divide
Rainbow Develops In Wake of Major Rain Event
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Photograph Thoughts...
"With the evening rains, a rainbow appears that drops behind the trees."

Rain continued to fall at a torrid pace during the first week of August across the High Knob Massif area of Wise, Scott, and Lee counties.

( In head of Little Stony Creek & Burns Creek )
August 2012 Rainfall Days
Robinson Knob of High Knob Massif
Observers - Otis & Nancy Ward
Elevation 3240 feet

( Daily Amounts Ending At 8 AM )

8/1:  1.14"
8/2:  0.03"

8/4:  0.20"
8/5:  0.35"
8/6:  0.79"
*8/7:  1.34"

Total: 3.85"
( Ending at 8 AM August 7 )

Total Since July 1: 18.03"

Total Since June 1: 21.10"

2012 Total: 46.26" ( M )

*Additional rain fell during the day after 8 AM.
( 0.51" on nearby automated gauge )

( M ) - Indicates missing moisture in deeper falls of winter snow.

Local rainfall amounts reached 4.00" to 5.00" during the first week of August in the main crest zone of the massif, west of Robinson Knob ( as of 7 AM August 7 ).

Precipitation totals in 2012 have reached 45.00" 
to 50.00"+ in wetter portions of the High Knob Massif area, from the head of Big Cherry Basin eastward along the highcountry straddling the Wise-Scott border and downward into the City 
of Norton, through this first week of August ( ** ). 

**A local mininimu of 40.00" to 45.00" has been noted in the southwestern portion of Big Cherry Basin where heavy rain cores in thunderstorms have repeatedly flanked, or developed around, the location of Big Cherry Dam this summer.