Saturday, November 12, 2011

Late Autumn In The Appalachian Highlands


October 21, 2011
High Knob Landform
Shillalah Creek of the Upper Cumberland River Basin
Shillalah Falls - Cumberland Gap National Historical Park
Photograph by Harold Jerrell - © All Rights Reserved.

Curly bark of Yellow Birch ( Betula alleghaniensis ) enhances the beauty of Shillalah Falls where pristine whitewater tumbles off the lofty backbone of Cumberland Gap National Historical Park, resting upon the rugged northwestern mountain flank of the great High Knob Landform ( NW forelimb of the Powell Valley Anticline of the Cumberland Overthrust Block ).

Late Autumn in the Appalachian Highlands is a special time as all life prepares for the coming of winter to these ancient mountains, where four seasons of truly dramatic contrast exist like few other places on planet Earth.

October 22, 2011
Cumberland Gap National Historical Park
Upper Falls of Majestic Shillalah Creek
Photograph by Harold Jerrell - © All Rights Reserved.

Rising amid the wondrous confluence of Brush and Cumberland mountains, at over 3300 feet in elevation, Shillalah Creek is a pristine beauty that drains Hensley Flats into a winding mountain top gorge carved into the rugged, sandstone capped backbone of the National Park.

October 21, 2011
Lower Falls of Shillalah Creek
Photograph by Harold Jerrell - © All Rights Reserved.

Rolling highlands of historic Hensley Settlement hide the fact that Shillalah Creek drops some 2000 vertical feet to its eventual union with Clear Fork of Yellow Creek of the Cumberland River. 

Shillalah Creek plunges from the National Park through a portion of the adjoining Shillalah Creek Wildlife Management Area, a 2535 acre tract along the northwestern slopes of Brush Mountain in Bell & Harlan counties of extreme southeastern Kentucky. 

October 22, 2011
Hensley Flats of Cumberland Gap National Park
Finley Hensley Home In The Hensley Settlement
Photograph by Harold Jerrell - © All Rights Reserved.

Martins Fork of the Cumberland River drains the northeastern end of these majestic highlands, taking a much longer journey off this very unique mountain flank of the High Knob Landform which unites the Upper Cumberland & Upper Tennessee river basins.

American Whitewater Class V

October 22, 2011
Tennessee Valley Divide
Cumberland Gap National Historical Park
Old Timey Rake - Highlands of Hensley Settlement
Photograph by Harold Jerrell - © All Rights Reserved.

Reflections upon an autumn which has already been wet, with 15.31" of total precipitation measured in the City of Norton from September 1 to November 4, finds an energetic atmosphere prime for development of heavy rain events as the seasonal clash of air masses intensifies during the November 14-24 period. 

October 21, 2011
Hensley Settlement of Cumberland Gap NHP
Autumn Reflections - Gibbons Cabin Window
Photograph by Harold Jerrell - © All Rights Reserved.

More than one heavy rain event will be possible across the famed southern Appalachians before Thanksgiving, amid some wild up and down temp swings, with an eventual trend toward more prolonged coldness heading into late November.

GOES East Water Vapor Imagery - 3:15 PM November 13, 2011

November is typically the month that finds the largest ramp up of orographic forcing as surface temperature gradients develop pressure gradients aloft that drive increasingly strong winds into the High Knob Landform.

The Thermal Wind Equation of mathematics demands that wind shear develop in the vertical atmosphere above horizontal differences in temperature at the surface, such that horizontal changes in temperature at the surface drive the formation of jet streams aloft and seasonal weather changes.  The entire process being driven by the Sun and subsequent imbalances of energy transfer forming across surface-air interfaces of planet Earth.  

October 22, 2011
High Knob Landform
Cumberland Gap National Historical Park
Fern Laden Slopes Below Willie Gibbons Barn
Photograph by Harold Jerrell - © All Rights Reserved.

Late autumn in the Appalachians is influenced by conditions which develop thousands of miles away from these ancient mountains, in places like the Pacific Ocean and the darkening expanses of Siberia on the super-continent of Eurasia.  

These far away influences are called climate Teleconnections, with El Nino & La Nina being examples of two of the better known phases of the El Nino Southern Oscillation ( ENSO ).  Another one proving critical to development of winter patterns in the eastern USA is the autumn expansion of snow cover across Eurasia.

October 22, 2011
AM Frost - Cumberland Gap National Historical Park
Photograph by Harold Jerrell - © All Rights Reserved.

A general 100" to 150"+ of snow fell across upper elevations in the High Knob Massif during the past three winter seasons with the last two, in particular, featuring an above average expansion of mid-late autumn snow cover across Siberia.


October 22, 2011
Hensley Settlement of Cumberland Gap NHP
Beautiful Wood Grain of School House Door
Photograph by Harold Jerrell - © All Rights Reserved.

One may only imagine how many cold, wind driven snowfalls have been held at bay by this beautiful old door of the Hensley Settlement school perched at over 3300 feet elevation on Cumberland Mountain.

October 21, 2011
Elevation 3336 feet
Hensley Settlement Cemetery
Shadow of Cross On Cemetery Stone
Photograph by Harold Jerrell - © All Rights Reserved.

Autumn 2011 snow cover has increased rapidly at high latitudes and is running well above average within the critical Siberian sector.  If research during the past decade is correct this may signal another bad winter ahead for the Appalachians ( * ).


*( Updated - Late November 2011 )
Mixed signals in the Siberian sector during October 2011 has led Judah Cohen to suggest the 2011-12 season will not be as severe as last winter across the eastern USA, but with "nervous" caution.

Much below average early October snow cover in Siberia gave way to a rapid late month surge in snowfall to yield an above average snowpack, making the month as a whole "average" ].

Potential for extreme weather events during winter-spring of 2011-12 is also enhanced by a distinct Sub-tropical jet stream, a weak El Nino, and a notable Madden-Julian Oscillation feeding energy into the Polar jet stream.

During the past two winter seasons, as well documented on this website, prolonged and significant snows did not arrive until December ( as impacts of Siberian snow cover forcing tend to possess a lag time which is analogous to that of ENSO forcing ).

October 31, 2011
Martin Creek of the Powell River Basin
Late Autumn Color In White Branch Gorge
Photograph by Harold Jerrell - © All Rights Reserved.

While every season is unique with its own special combination of weather conditions forced by larger scale climate features, odds on the ones upcoming currently favor wetter and colder than average conditions for winter & spring.

Note that wetter does not necessarily mean snowier.  In fact, short-term climatology would suggest that 2011-12 winter snowfall will end up being under 100" on High Knob given that since the 1992-93 season there has never been 4 consecutive 100"+ seasons ( last winter made the third ) despite the 108.4" average for the past 19 winters. 

  Only TIME will tell for certain!

October 31, 2011
Cumberland Mountain of the High Knob Landform
White Branch of Martin Creek of the Powell River
Photograph by Harold Jerrell - © All Rights Reserved.

My friend & photographer Harold Jerrell last made a bold trek into White Branch Gorge during February 2010.


October 31, 2011
Autumn Majesty Of Tumbling White Branch
Photograph by Harold Jerrell - © All Rights Reserved.

Harold returned at the end of October 2011 to much more tame conditions and the free flow of pristine water!

October 31, 2011
Plunging White Branch Falls
Photograph by Harold Jerrell - © All Rights Reserved.

A single Sugar Maple ( Acer saccharum var. saccharum ) leaf accentuates this gorgeous shot of plunging White Branch Falls.


Climate Statistics For
October 2011

October 31, 2011
High Knob Landform
White Branch of Martin Creek of the Powell River
Photograph by Harold Jerrell - © All Rights Reserved.

( Lower Elevations of Russell Fork Basin )
Clintwood 1 W - Elevation 1560 feet
Average Daily MAX: 64.4 degrees
Average Daily MIN: 38.5 degrees
MEAN: 51.4 degrees
Highest Temperature: 78 degrees
Lowest Temperature: 26 degrees
October Rainfall: 3.74"
October Snowfall: Trace
2011 Precipitation: 52.03"

( Northern Base of High Knob Massif )
City of Norton - Elevation 2141 feet
Average Daily MAX: 61.9 degrees
Average Daily MIN: 36.7 degrees
MEAN: 49.3 degrees
Highest Temperature: 77 degrees
Lowest Temperature: 22 degrees
October Rainfall: 5.04"
October Snowfall: 0.3"
2011 Precipitation: 62.75"

( Along the Tennessee Valley Divide )
Nora 4 SSE - Elevation 2650 feet
Average Daily MAX: 61.0 degrees
Average Daily MIN: 43.5 degrees
MEAN: 52.2 degrees
Highest Temperature: 76 degrees
Lowest Temperature: 30 degrees
October Rainfall: 3.38"
October Snowfall: 0.4"
2011 Precipitation: 47.59"

( Northern End of The Cedars )
Jonesville 3.1 WSW - Elevation 1422 feet
Average Daily MAX: 67.5 degrees
Average Daily MIN: 40.4 degrees
MEAN: 53.9 degrees
Highest Temperature: 82 degrees
Lowest Temperature: 23 degrees
October Rainfall: 4.12"
2011 Precipitation: 46.56"

In the High Knob high country, average October temps varied from low-mid 50s by day at highest elevations to the low-mid 30s at night in colder mountain basins ( around 40 on exposed ridges ).

October was wet with around 5.00" of precip that included several inches or more of snow at highest elevations in the main crest zone of the massif ( snow fell 4 different times during the month on Eagle Knob ). 



Another Wet Year In 
The High Knob Landform

October 30, 2011
MilkweedAsclepias spp. ) Seed Pod In Morning Light
Photograph by Roddy Addington - © All Rights Reserved.

Another wet year about to get much wetter is the theme of 2011 in the High Knob Landform, with 65" to 70"+ of total precipitation amid wetter portions of the High Knob Massif through the end of October.

Big Cherry Dam of High Knob Massif
Monthly Precipitation Totals
Elevation 3120 feet

2008
November:  4.36"
December: 8.49"

2009
January: 9.23"
February: 4.36"
March: 5.51"
April: 5.40"
May: 7.07"
June: 5.44"
July: 8.42"
August: 7.08"
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"
September: 2.88"
October: 2.84"
November: 4.05"
*December: 7.35"

2011
January: 4.51"
February: 4.53"
March: 9.85"
April: 10.08"
May: 5.38"
June: 6.16"
July: 7.18"
August: 4.94"
September: 7.28"
October: 5.05"

2011 Total: 64.96" ( M )

Orographic Forcing Season Total
November 2010-April 2011: 40.37" ( M )
( 6.06" per month average )

12-Month Total: 76.36" ( M )

24-Month Total: 145.94" ( M )

36-Month Total: 224.75" ( M )

36-Month Mean Monthly Precip: 6.24"

Mean Per 12-Month Periods: 74.92" ( M )

( * ) - Indicates that total was estimated or partly estimated due to severe winter conditions.

( M ) - Denotes that total precipitation was greater than rain gage total due to evaporation between hand-measurements observed at the Dam ( the mean evaporative loss is estimated to have been 3.00" to 3.50" per year as partly based upon observed losses at Clintwood 1 W ) and deep falls of snow greater than the rain gage could physically hold.

All measurements courtesy of Superintendent Gary Hampton & Staff at the Big Stone Gap Water Plant in South Fork Gorge.

Perhaps the most striking aspect of 2011 precip at Big Cherry Dam was that it missed many big rains during the convective season which hit adjacent portions of the massif.

Otherwise, its the same drill, actual raw rain gage totals at the Dam are lower than what really fell due to evaporation between hand-measurements and losses in deeper falls of winter snow.

Hand-measurements are typically made every 5 to 9 days, or once per 7 days on average, such that some evaporation loss occurs from the NWS rain gage.  It is important to note this aspect when comparing totals to other locations.

Melting Frost & Thistle Species ( Cirsium spp. )
Photograph by Roddy Addington - © All Rights Reserved.

The first ten months of 2011 produced simply incredible extremes in precipitation across the Old Dominion, from more than 70" in wetter parts of the High Knob Massif to less than 30" in driest portions of eastern Virginia.


October Rainfall Totals & 2011
Precipitation Totals From Across
Virginia & The District of Columbia
*( 2011 Totals from January 1 to October 31 )

John H. Kerr / Buggs Island Dam
October Rainfall: 3.36"
2011 Precipitation: 27.24"
( 5 missing days January-March )

Lynchburg
October Rainfall: 2.95"
2011 Precipitation: 31.10"

New Castle RAWS
October Rainfall: 2.37"
2011 Precipitation: 31.73"
( 7 missing days October )

Eastville
October Rainfall: 2.15"
2011 Precipitation: 31.82"
( 1 missing day January )

Danville
October Rainfall: 3.45"
2011 Precipitation: 31.84"

Pulaski 2 E
October Rainfall: 2.79"
2011 Precipitation: 32.45"

Martinsville Filter Plant
October Rainfall: 3.92"
2011 Precipitation: 32.81"

Wallops Island
October Rainfall: 3.59"
2011 Precipitation: 32.81"

Gathright Dam
October Rainfall: 2.42"
2011 Precipitation: 33.34"

Lexington
October Rainfall: 3.41"
2011 Precipitation: 33.97"
( 2 missing days August )

Wytheville 1 S
October Rainfall: 2.17"
2011 Precipitation: 34.02"
( 1 missing day August )

Kerrs Creek 6 WNW
October Rainfall: 3.03"
2011 Precipitation: 34.29"

Emporia 1 WNW
October Rainfall: 2.58"
2011 Precipitation: 34.34"
( 2 missing days June )

Covington Filter Plant
October Rainfall: 2.44"
2011 Precipitation: 34.39"
( 1 missing day August )

Edinburg
October Rainfall: 2.51"
2011 Precipitation: 34.65"
( 1 missing day February )

Appomattox
October Rainfall: 3.72"
2011 Precipitation: 35.29"

Philpott Dam 2
October Rainfall: 3.93"
2011 Precipitation: 35.47"
( 5 missing days January-March )

Blacksburg
October Rainfall: 2.94"
2011 Precipitation: 36.36"

Independence 1.3 S
October Rainfall: 2.36"
2011 Precipitation: 36.44"

Roanoke
October Rainfall: 4.06"
2011 Precipitation: 36.54"

Bluefield ( West Virginia )
October Rainfall: 2.67"
2011 Precipitation: 36.63"

Woodstock 2 NE
October Rainfall: 2.77"
2011 Precipitation: 37.09"
( 6 missing days during year )

Bland
October Rainfall: 2.35"
2011 Precipitation: 37.37"
( 3 missing days January )

Stuart
October Rainfall: 3.41"
2011 Precipitation: 37.53"
( 6 missing days January-February )

Saltville 1 N
October Rainfall: 2.68"
2011 Precipitation: 37.86"

Alberta 5 N
October Rainfall: 4.21"
2011 Precipitation: 38.00"

Radford 3 N
October Rainfall: 2.98"
2011 Precipitation: 38.16"

Front Royal
October Rainfall: 4.25"
2011 Precipitation: 38.28"
( 6 missing days during year )

Farmville 2 N
October Rainfall: 4.28"
2011 Precipitation: 38.46"

Christiansburg
October Rainfall: 3.32"
2011 Precipitation: 38.87"

Staunton WTP
October Rainfall: 2.82"
2011 Precipitation: 39.14"

Buckingham
October Rainfall: 5.89"
2011 Precipitation: 39.47"
( 1 missing day August )

Washington Dulles Airport
October Rainfall: 6.27"
2011 Precipitation: 39.56"

Marion 4.4 WSW
October Rainfall: 2.64"
2011 Precipitation: 39.63"
( 4 missing days during year )

Waynesboro WTP
October Rainfall: 3.54"
2011 Precipitation: 40.28"
( 2 missing days in March & August )

Dale Enterprise
October Rainfall: 3.37"
2011 Precipitation: 40.47"

Washington National Airport
October Rainfall: 3.91"
2011 Precipitation: 40.05"

Charlottesville
October Rainfall: 5.32"
2011 Precipitation: 40.81"

Millgap 2 NNW
October Rainfall: 3.44"
2011 Precipitation: 40.83"

Richmond
October Rainfall: 2.79"
2011 Precipitation: 41.33"

Richlands
October Rainfall: 2.90"
2011 Precipitation: 41.40"

Burkes Garden
October Rainfall: 3.91"
2011 Precipitation: 41.58"
( 1 missing day August )

Louisa 
October Rainfall: 4.13"
2011 Precipitation: 41.68"

Luray 5 E
October Rainfall: 3.84"
2011 Precipitation: 41.98"

Trout Dale 3 SSE
October Rainfall: 3.08"
2011 Precipitation: 42.18"
( 1 missing day August )

Hot Springs
October Rainfall: 4.13"
2011 Precipitation: 42.32"
( 1 missing day January )

Holcomb Rock
October Rainfall: 5.31"
2011 Precipitation: 42.45"
( 2 missing days August )

Glasgow 1 SE
October Rainfall: 5.62"
2011 Precipitation: 42.91"
( 1 missing day August )

Copper Hill 6.2 S
October Rainfall: 5.38"
2011 Precipitation: 43.01"

Lebanon
October Rainfall: 2.58"
2011 Precipitation: 44.08"

Galax WTP
October Rainfall: 2.67"
2011 Precipitation: 44.28"
( 1 missing day August )

Grundy
October Rainfall: 3.55"
2011 Precipitation: 44.72"

Rocky Mount ( Virginia )
October Rainfall: 4.12"
2011 Precipitation: 45.09"

Woolwine
October Rainfall: 5.41"
2011 Precipitation: 45.21"
( 1 missing day August )

Jonesville 3.1 WSW
October Rainfall: 4.12"
2011 Precipitation: 46.56"

( Long Ridge )
Nora 4 SSE
October Rainfall: 3.38"
2011 Precipitation: 47.59"

Norfolk
October Rainfall: 2.13"
2011 Precipitation: 47.70"

Mustoe 1.2 SW
October Rainfall: 3.27"
2011 Precipitation: 49.08"
( 4 missing days during year )

Williamsburg 2 N
October Rainfall: 4.24"
2011 Precipitation: 51.26"
( 3 days missing during year )

Meadows of Dan 5 SW
October Rainfall: 4.73"
2011 Precipitation: 51.54"

Clintwood 1 W
October Rainfall: 3.74"
2011 Precipitation: 52.03"

Appalachia Lake Water Plant
October Rainfall: 4.29"
2011 Precipitation: 54.91"

Coeburn Filter Plant
October Rainfall: 3.67"
2011 Precipitation: 56.72"

Big Stone Gap Water Plant
October Rainfall: 4.78"
2011 Precipitation: 58.03"

Norton Water Plant
October Rainfall: 5.04"
2011 Precipitation: 62.75"

Big Cherry Dam of High Knob Massif
October Rainfall: 5.05"
2011 Precipitation: 64.96" ( M )

Robinson Knob of High Knob Massif
October Rainfall: 4.99"
2011 Precipitation: 65.36" ( M )

( M ) - Denotes that total precipitation was greater than rain gage total due to evaporation between hand-measurements and physical gage losses in deep falls of snow.

( * ) - Days denoted as missing may or may not have had any measurable precipitation at the indicated sites.  All station data should be considered as preliminary until officially checked and accepted by the National Climatic Data Center.


November Opens WET With 
Large Vertical Temperature Spreads

Middle Elevation Thermal Belt
Long Ridge of the Tennessee Valley Divide
The Last Colors Of Autumn 2011 - November 5, 2011
Photograph by Wayne Riner - © All Rights Reserved.

Wayne Riner Thoughts...
"The first light of morning touches the tips of the high ridges to reveal the last few leaves of fall colors.  The red in the foreground are "burning bushes" at the edge of the yard."

Looking across a sea of fog in the wake of the first significant rain of November 2011, my friend and photographer Wayne Riner captures a simply magnificent view of this condensed cloud vapor covering the many hollows and lower ridges of the Russell Fork Basin between Pine Mountain and the Tennessee Valley Divide ( with its twisting ridges ).

NASA Visible Image At 8:45 AM - November 5, 2011

From space the fog bank was visible filling most of the Russell Fork & Levisa Fork basins, with the higher terrain of central and southern Wise County resting above the low clouds like Long Ridge in southern Dickenson. 

Observe the long, linear band of fog in the Clinch River Valley of Russell & Scott counties which is banked up to Guest River Gorge and adjoining southeast portions of the High Knob Massif, with a thinner and more shallow fog layer within Powell Valley and the Powell River Valley of Wise and Lee counties inside the HKL.

Min temperatures in upper 10s to upper 20s were common amid colder mountain valleys during the first 9 days of November, in sharp contrast to 30s & 40s on exposed mid-upper elevation ridges.

This created large temperature contrasts in the vertical on nearly every morning to again illustrate why forecasts should always include a temperature range to account for such distinct differences ( instead of using a single number or narrow middle range value ).

Climate Stats For November 1-9

City of Norton - Elevation 2141 feet
Average Daily MAX: 58.4 degrees
Average Daily MIN: 25.6 degrees
MEAN: 42.0 degrees
November 1-9 Rainfall: 1.09"
2011 Precipitation: 63.84"

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