Monday, November 30, 2009

November 2009 - An Unusual Month


November 30, 2009
Calcareous Core of High Knob Massif
Majestic Misty Waves of Wind Blown Fog
Photograph by Roddy Addington - © All Rights Reserved.

Rising upward across rugged mountain walls of the High Knob Massif, rimming Powell Valley, misty waves of wind blown fog reveal hidden hollows and folds not typically seen on clear days.

Ribbons and multiple layers of white vapor swirl through tree tops and rocky crevices of the landscape to create new scenes with every passing moment, as captured by photographer Roddy Addington during this final afternoon of November 2009.

South Fork Gorge of High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

Rolling across the highcountry, clouds break and thicken to cast varying shades of light upon this magnificent setting, during an afternoon many would deem as simply nasty!

Darkening Shadows Beneath Orographic Cap Clouds
Photograph by Roddy Addington - © All Rights Reserved.

Wet snowflakes, falling through dense layers of cloud vapor capping the High Knob Massif crest zone, would eventually dust the summits with a substance rarely observed during November.

SNOW!

November 2009 was an unusual month. It began and ended wet, with many dry hours in between.

In numerous ways, November was more like October ( minus it's gorgeous colorations ) than the end of autumn!

November 2009 ended as the driest month in more than a year. Typically, that climatological distinction is owned by October.

It generated very little snow, even on the summits, which was more like that typically observed during October, when the first light snowfalls of winter whiten the highcountry.

An array of gorgeous sunrises, sunsets, and amazing displays of frosty cold mornings mixed with nocturnal fog formations made the month spectacular amid the great High Knob Landform.

Even without the more typical array of snow and RIME events!

Magnificent Landscape - High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

My friend Gary Hampton, superintendent of the Big Stone Gap Water Plant sitting amid great South Fork Gorge, reports that 3.88" of rain fell at Big Cherry Dam of High Knob during November.  That was 1.27" more than measured down at the Water Plant, and 2.01" more than observed at my official NWS station near Clintwood ( outside the lifting zone of the massif ).

November 2009 was the driest month observed at Big Cherry Dam since last October.

Monthly Precipitation Totals for 2009

Big Cherry Dam of High Knob Massif
Elevation: 3120 feet

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"

2009 Total: 69.84" ( M )
12-Month Total: 78.33" ( M )

In reality, as previously discussed, there has been around 3.00"   of evaporational loss at Big Cherry Dam during the year, between hand-measurements, so that if it had been possible to measure every day by hand the 2009 tally through November would have been approximately 73.25" .

The above not including wind induced rain gage undercatches, and other sources of moisture loss such as that which is more common with frozen precipitation forms.

For an overview of this, please reference the following section of my website:


The evaporational loss at Big Cherry Dam being based upon observed losses at my official NWS station, in Clintwood, during the past year.

Autumn precipitation in the High Knob highcountry was enough to keep the water rolling, and Big Cherry Dam overflowing its spillway throughout the entire month of November 2009.

Water draining from eastern portions of the massif, out of Bark Camp Lake, also kept whitewater moving despite somewhat less total precipitation than observed within the Big Cherry Basin ( as captured below by mushroom expert and photographer Johnny Stanley ).

High Knob Massif
Upper Falls of Little Stony Creek Gorge
Photograph by Johnny Stanley - © All Rights Reserved.

Joe Carter reports that the Norton Water Plant had 2.77" of rainfall during November, which was 1.91" below their 1983-2004 mean ( with some missing data prior to 1998 ). 

Monthly Precipitation Totals for 2009

City of Norton Water Plant
Elevation: 2342 feet

January: 7.34"
February: 3.27"
March: 5.24"
April: 5.13"
May: 9.72"
June: 7.95"
July: 5.46"
August: 5.19"
September: 6.08"
October: 3.46"
November: 2.77"

2009 Total: 61.61"
12-Month Total: 70.19"

The meteorological autumn season of September-November generated 17.33" of rain at Big Cherry Dam of High Knob, and 12.31" in the City of Norton. 

A general 13.00-14.00"+ of autumn precipitation fell from Robinson Knob to Eagle Knob, with my friends Otis & Nancy Ward measuring 13.31" during the autumn at their lovely home
( 3230 feet elevation ).

Autumn rains generally varied from just below average, to just above average, across the Cumberland Mountains ( falling in between the EXTREMES highlighted below ).

Pristine Water - Little Stony Gorge High Knob Massif
Photograph by Harold Jerrell - © All Rights Reserved.

Snowfall was MUCH below average during autumn, with only a general 0.5" to 3.0" across upper elevations, above 3000 feet, during the season.  A dramatic departure from last autumn, when a general 2-3 FEET was observed within upper elevations of the High Knob Massif during October 1-December 1.


Regional Extremes During November 2009

Extreme was the word to describe the regional setting during November, with HUGE variations in rainfall totals between the Ohio River Valley and Atlantic Coast.

For a change from previous 2009 patterns, this unusual November generated extreme dryness across much of eastern Kentucky and West Virginia, and extreme wetness from the New River Valley to the Virginia Tidewater.

Thanks mainly to remnants of former hurricane Ida, the following Virginia locations had record setting November rainfall tallies:

Richmond: 9.60" - Wettest November
Danville: 8.33" - 2nd Wettest in 62 years
Lynchburg: 8.19" - 2nd Wettest in 117 years
Roanoke: 7.44" - 3rd Wettest in 98 years
Blacksburg: 5.12" - 5th Wettest in 58 years.

The 9.60" of rain in the state capitol of Richmond was much needed, and boosted the 2009 precipitation total to 40.16" ( just shy of average for the year ).

By contrast, the following locations reported among their driest November's on record.

November 2009 Precipitation Totals

Kentucky
Jackson: 0.80" - Driest November
London: 0.62" - 2nd Driest
Lexington: 0.96"

West Virginia
Charleston: 0.74"
Huntington: 0.79"
Elkins: 0.84"
Parkersburg: 0.93"

Perhaps the most dramatic regional swing occurred in Paducah, Ky., which had 10.55" of rain to establish its wettest October on record, followed by a mere 0.56" during the next 30-days to mark its driest November of all-time.  Back to back monthly EXTREMES!

Saturday, November 21, 2009

Glorious November Amid High Knob Landform


November 20, 2009
Remnant Massif of The High Knob Landform
Lonesome Pine Stands Above Fog - Powell Valley
Photograph by Roddy Addington - © All Rights Reserved.

A classic layer of fog, spreading out beneath scenic Powell Valley Overlook in Wise County, Va., was captured in gorgeous detail by photographer Roddy Addington early Friday morning.

Confined within the calcareous heart of the great High Knob Massif, and lapping up against its rugged mountain walls like water sloshing in a lake, the fog layer remained in place for hour after hour before dissipating.

Simply AWESOME!

The fluid nature of our amazing atmosphere revealed yet again!

Reference my 2009-10 Winter Discussion for more details
on the fluid nature of the air around us:


Flickering Like Fireflies - Vehicles Emerge From Fog
Photograph by Roddy Addington - © All Rights Reserved.

Flickering like fireflies, tiny headlights emerging from the fog bank can be seen far beneath the plunging slopes of Little Stone Mountain ( the NW flank of the High Knob Landform and its remnant massif ).

Such scenes truly illustrate how very TINY we are amid this great mountain landscape, as U.S. 23 rises above the fog to create a simply spectacular drive for those along this exceptionally scenic stretch of famed Country Music Highway.

Turning pinkish-orange with the rising of the morning sun, lines of orographic wave clouds add to this already magical setting as air aloft flows across the High Knob Landform ( HKL ).

Could it get any better?

Weather conditions generating this awesome setting were a clash between lingering low-level moisture, in the wake of a cloudy, chilly, and damp November 19, and the transport of drier air aloft into mid-upper elevations.

A frosty cold morning in the City of Norton, with 28 degrees at the newly installed Norton Elementary School AWS Weatherbug site, was in notable contrast to 30s within foggy locations.

[ Downslope funneling of drier air aloft, from upper reaches
of the High Knob Massif, combined with higher elevations in the Norton Valley to dissipate most of the initial fog formation observed in the City ].


Glorious Sunrises & Sunsets 
In The High Knob Landform

November 2009 has featured many glorious sunrises and sunsets within the great High Knob Landform, with photographer Harold Jerrell showcasing spectacular examples from Lee County.

In The High Knob Landform
Awesome Colors Above The Farm
Photograph by Harold Jerrell - © All Rights Reserved.

A wondrous sky, streaked with orographic wave clouds, stands in contrast to the dark, wavy crest of Wallen Ridge in Lee County, Virginia.

    Wondrous Sky Over Wallen Ridge of HKL
Photograph by Harold Jerrell - © All Rights Reserved.

At home within the great calcareous heart of the High Knob Landform ( HKL ), and ringed by its ruggedly majestic mountain arms, is a peaceful solitude not commonly found in the world today.

At Home In The HKL
Photograph by Harold Jerrell - © All Rights Reserved.


Looking To The High Knob Landform
And Tennessee Valley Divide

Sunrise views looking southwest to southeast, toward the High Knob Landform and across the Tennessee Valley Divide, are often just spectacular from the highlands of southern Dickenson County.

                                        Glorious Morning Sunrise
Photograph by Wayne Riner - © All Rights Reserved.

Changing colors through precious moments of time, as captured by photographer Wayne Riner and enhanced by orographic wave clouds rippling across the mountains, are often some of the most spectacular aspects of such amazing scenes!

Changing Colors of Morning Glory
Photograph by Wayne Riner - © All Rights Reserved.

The role of orographics ( mountain influences ) should never be taken for granted in shaping majestic skies above the great HKL and Cumberlands!

Stacked Waves & Rolls
Photograph by Wayne Riner - © All Rights Reserved.


Tuesday, November 17, 2009

Winter 2009-10: The Good, Bad, And UGLY


Wooly Bear Caterpillar ( Pyrrharctia isabella )
Photograph by Roddy Addington - © All Rights Reserved.

Unlike our beloved Wooly Bears, as captured above by my friend and photographer Roddy Addington, the road to predicting what the coming winter will be like is not pretty, cute, and cuddly.

It's pure-dee UGLY!

By the way, Wooly Bear Caterpillars ( Pyrrharctia isabella ) wonder how in the world they ever got caught up in this chaos?

Wooly Bears are the larval form of the Isabella Tiger Moth.  They emerge in autumn, just before winter, and are actually able to survive frigid conditions by producing a substance that essentially is a natural form of antifreeze!

They naturally vary in color from brown to black, with the banding taken to represent what the upcoming winter will be like being markers of age. 

[ To again be completely honest, it can be a BIT more complicated since their family of Arctiidae does ONLY contain 11,000+ known species across the planet...but I'm working an angle here, so hang with me! ].

Yes, indeed, youngsters tend to be mostly black and the older, mature elders of the species tend to be mostly brown.

The BANDING actually marks different instar stages, so that its indicative of age and maturity, not to future weather. 

YOU SILLY ole Homo sapiens sapiens!

Oh well, back to the drawing board!

Now this is where it get's kinda UGLY, because the simple, honest, and sincere truth is that NO ONE ALIVE today, nor any Super-MACHINE, can tell you what the upcoming winter will be like weeks, and dare we say months, in advance!!

Anyone can guess that it will be either GOOD or BAD ( depending upon your definition of such ), and be right 50 percent of the time ( like tossing a single, unbiased coin ).

Although many valient efforts are made, and some claim HIGH success rates, the real nitty-gritty of the UGLY is that important details of daily, weekly, and monthly weather variations are sorely lacking for specific locations where you and I live, work, and play.

[ A large-scale trend that might dominate a couple weeks, or a MONTH, is often easier to define in advance than are the daily details of short-term weather changes.  In fact, some interesting climate patterns have been found that are just as important to future winter conditions as are the ones driven by the well known ENSO ( El Nino & La Nina of the Southern Oscillation )  ].

WOW, I'm glad that I am no foreACTOR, I mean foreCASTER!

[ Sorry my weather BIZ friends ( used to be ), I just couldn't let that one pass!!! ].

Seriously, there are some very good forecasters who put in a great amount of time and effort to crank out winter predictions ( a few of which I will be linking to later for you to check ).

Meanwhile, we'll be looking at the GOOD and BAD of this chaotic situation!

GOOD News - Major Forcings
Identified ( at least SOME of THEM )!

Frosty Cold Morn - Powell Valley of High Knob Massif
Photograph by Roddy Addington - © All Rights Reserved.

Will the winter ahead feature more frosty cold mornings like captured by Roddy above, OR will it feature more dazzling WHITE mornings beneath a blanket of sparkling SNOW?

That is the BIG question which is ALWAYS numerial-UNO in the minds of both lovers of the "white stuff," and haters alike!

The Good News during 2009-10 is that there is a teleconnection running in which we know will have a major influence upon weather conditions.

It is the positive phase of ENSO, The El Nino-Southern Oscillation.

You see, El Nino is only the above "normal" warming of sea surface temperatures across the equatorial Pacific Ocean.  While that is indeed the real forcing factor, the positive phase of ENSO, of which El Nino episodes represent, is more than just oceanic warming!

During the 1920s, to present historical insight, a researcher by the name of Sir Gilbert Walker was in India trying to unravel the rather mysterious nature of the annual monsoon that is such a prominent feature of the Asian climate.

He observed that different seasons would produce monsoons of varying intensities.  Some seasons, for example, would bring great flooding, while others would produce so little rain that drought conditions would engulf the region.

These fluctuations could mean the difference between life and death for millions of people, such that the discovery of a way to predict monsoonal intensities would be, needless to say, of enormous value.

In his research Walker discovered what is known today as a

TELECONNECTION.

A teleconnection is where weather conditions occurring in one region on earth can force changes in another region FAR away.

Walker found that when sea level pressures are low, relative to average, in India and the western Pacific, they tend to be high, relative to average, across the central and eastern Pacific.

Likewise, when sea level pressures are high in India and adjacent regions of the western Pacific they tend to be low ( relative to average ) across the central and eastern Pacific.

Walker named these pressure swings the Southern Oscillation.

He had discovered an important piece of the puzzle that is so commonly called El Nino today!

Some 40 year later another researcher named Jacob Bjerknes became the first to make a connection between abnormal sea surface temperatures and the oscillations in pressure discovered by Walker.

He had discovered the oceanic forcing component called El Nino.

El Nino is spanish for the "Christ child."  Fishermen along the coastlines of Ecuador and Peru, in South America, originally began using the term to name a weak and unusually warm ocean current that would appear on an annual basis around the time of Christmas. 

During some years this warming would become strong, with significant and locally disastrous impacts upon both their fishing and the landscape ( it would stop the upwelling of cold waters and cause deadly flooding along the windward slopes of the Andes ).

But how can this be?

How can something like this, so FAR away, impact the High Knob Landform and southern Appalachians?


The FLUID Atmosphere

Looking from Pine Mountain toward High Knob Landform
Photograph by Roddy Addington - © All Rights Reserved.

[ When the ever present water vapor becomes visible in the atmosphere, as seen above, its wavy, fluid nature will eventually emerge, sometimes, in dramatic and breathtakingly stunning fashion ].

As I always teach, the KEY to obtaining an understanding for the workings of our amazing atmosphere are based upon its FLUID nature.  Mathematics are essential for a complete understanding, but anyone can learn by the way I teach from my research experience.

If you are not blessed enough to stand upon our high mountains and capture a scene so glorious as that which was documented by photographer Roddy Addington above, then go to the nearest lake or pond!

If you drop a pebble into a pond, waves ripple away from the point of impact.  If you drop two pebbles separated by a distance, the waves from each point of impact ripple outward and interact with each other in various and interesting ways!

Two waves approaching each other can either interact in a constructive way, and combine energies to form a larger wave with more total energy, or they can interact in a destructive way to cancel ( or partially cancel ) each other out ( dissipating their energies ).

A small pebble generates small rippling waves, while a large rock dropped into the water generates BIG waves.

And so it is with the fluid ATMOSPHERE.

On micro to meso scales, as illustrated by Roddy's photograph above, the fluid nature of the air around us is so VERY evident, energetic, and simply MAGICAL.

[ In the above photograph, taken on Pine Mountain and looking outward toward the High Knob Landform ( HKL ), sun exposed mountain slopes and the cool, foggy lower terrain acted to generate a vast array of rising and sinking waves, rolls, and other ripples along the surface of a morning inversion layer, revealing the truly dynamic nature of the air around us at all times ( its just not always so visibly gorgeous )].

On the SYNOPTIC or LARGE scale, the pebbles and rocks in question are all the forcing factors, like El Nino or ENSO, which perturb the fluid.

El Nino is able to perturb the atmosphere via the abnormal warming of the sea surface which initially generates a vast array of micro-turbulence that begins mixing and overturning air in contact with the air-sea interface.

In time, and with persistence of the temperature anomaly, this micro-turbulence grows exponentially in its scope and intensity, such that deep convection forms above the warmed ocean. 

Like a fire, which begins as a mere flicker and turns into a raging inferno, the influence of initial oceanic warming grows to influence the pressure patterns across the entire expanse of the equatorial Pacific, marking the formation of a positive phase of ENSO.

[ Its negative phase is called La Nina, in short-hand terminology, and marked by abnormally cold sea surface temperatures which generate opposite pressure oscillations across the Pacific Basin ].

In this way, ENSO can be thought of as a rock dropped into the water, with waves rippling outward from its point of impact ( the equatorial Pacific Ocean ) throughout the surrounding fluid ( global atmosphere ).

The communication of the ENSO influence beyond the immediate region of the air-sea interface depends upon the sensitivity of the atmosphere to changes in deep convection.

When ENSO is running, it subjects the atmosphere to constant forcing as its energy ripples away from the equator to interact in complex ways with a myriad of other oscillatory atmospheric disturbances.

Thus, ENSO is a TELECONNECTION, since from its point of impact, energy in the form of rippling waves moves outward to perturb the air in locations FAR, FAR away from where it began.

A WEAK ENSO of positive phase is analogous to dropping a small pebble into a pond.  It generates waves, but they are not nearly as STRONG nor as far reaching as those generated by bigger pebbles, and can therefore be more easily overcome or canceled by other waves originating from different "pebbles" in the pond.

A STRONG ENSO of positive phase is therefore analogous to dropping a BIG rock into a pond, with generation of significant waves that are far reaching and dominant in their influence over other waves rippling throughout the fluid atmosphere.

The above being a greatly OVER-SIMPLIFIED analogy in order to aid understanding.  Some of the true complexity will be noted subsequently.

Sea Surface Temperature Anomalies - November 15, 2009
Image courtesy of Unisys Weather

The above graphic illustrates the present sea surface temperature anomalies across the globe.

The zone inside the YELLOW outlines the critical El Nino warming region.  Other areas of abnormally cold sea surface temperatures ( inside the PURPLE ), south of the Gulf of Alaska and the rugged Newfoundland Coast, are also very important ( especially if they persist over time ).

The current positive phased ENSO is moderate to borderline strong, and models run by the Climate Prediction Center indicate that it will remain at least weak to moderate through the 2009-10 winter season.

Here is a higher resolution sea surface temp anomaly map, courtesy of NOAA Satellite and Information Service ( NESDIS ) and the National Climatic Data Center ( NCDC ), which compares present anomalies to that of the recent 1971-2000 mean or base period ( soon to be replaced by 1981-2010 means ).


Here is a link to watch it change over time, courtesy of NCDC & NOAA:

http://lwf.ncdc.noaa.gov/oa/climate/research/sst/ani-weekly.html

[ An interesting note, during El Nino episodes the length of a day actually increases by a tiny fraction since the associated stronger westerly winds pushing against the surfaces of Earth require that its rotation slow ever so slightly, in order to abide by the law of conservation of angular momentum.  This according to a NASA funded research project and David A. Salstein ].

Using my analogy above, EVERY major disturbance or variation in the global atmosphere can be modeled as a pebble or rock dropping into it's fluid, with resultant waves rippling outward from where they originate.

All the other identified teleconnections are therefore included, as well as such things as the pattern and deposition of winter snow cover at mid to high latitudes.

A few other important teleconnections include:

AO - The Arctic Oscillation

NAO - The North Atlantic Oscillation

PNA - The Pacific North American Oscillation

EPO - The Eastern Pacific Oscillation

WPO - The Western Pacific Oscillation

MJO - The Madden-Julian Oscillation

PDO - The Pacific Decadal Oscillation

NPO - The North Pacific Oscillation

AAO - The Antarctic Oscillation

QBO - The Quasi-biennial Oscillation .

All of these teleconnections plus MANY more that are minor, or simply NOT yet known, are pebbles and rocks dropping into the fluid atmosphere.  Each one has positive, neutral, and negative phases, and each one impacts the atmosphere via waves rippling outward from their regions of origin.

ADD in the following facts:

1 ).  The Earth spins at 1038.0 miles per hour at the equator .

2 ).  The Earth's orbital speed around the sun is approximately 66.6 miles per hour.

3 ).  The Earth is frozen at the poles.

4 ).  The Earth is heated at the equator.

5 ).  The Earth's surface is 71 percent covered by water.

6 ).  The Earth has many mountain ranges that extend above its PBL ( planetary boundary layer ).

7 ).  The surfaces are Earth are CONSTANTLY being perturbed and changed by mankind, in addition to mother nature.

[ The surfaces of Earth act like synapses of neurons in the brain, or the interfaces of a computer, where information is selectively relayed to all other parts of the system.

Mankind, of all possible species alive today, possesses the ability to impact Earth most through changes he makes in its surfaces ( thus disrupting the natural communication and flow of diverse forms of energy within the climatic system that by definition includes the biosphere )].


The Complexity of the Problem

The complexity of the problem facing a super-computer, not to mention a human forecaster, is to take the positive phase of ENSO and to combine it with ALL of the other teleconnections and factors listed above.

That roughly ( very roughly ) covers the LARGE or Synoptic-scale.

Now add in the vast array of regional to local scale forcing factors, such as the orographics of the High Knob Landform, to the above mixture, shake it up, and what do you GET??

You get back to the pure-dee UGLY in which we started!

Hey, I thought this was the GOOD NEWS section?

Well, there is HOPE.  All is not lost.  Amid this resultant chaos, of which the above generates, there is some trends which can be assimilated into at least a bit of ORDER.


What We Know:
Thank God for Climatology

Yes, indeed, thank the good Lord above for daily weather observers, researchers, and climatologists who GRUNT out the hard work of not days, not weeks, not years, but literally decades and life-times to find unknown facts and patterns which could not be discovered otherwise.  Its no glory job, that is for certain!

What we know from observations and research, over long time periods, produces some basic generalizations that I will break down into two categories.


1 ). Cold-Snowy Winter

For those wishing for a cold, snowy winter within the High Knob Landform, the southern Appalachians, and across the eastern United States in general, the following teleconnection phase combinations would be nice:

-AO
-NAO
+PNA
-EPO
+/-ENSO
+MJO
+A deep covering of snow across
eastern Canada and the NE U.S.A

 --NAO with --EPO = Prolonged Arctic Outbreak
[ Strongly negative NAO & EPO = Arctic Outbreak ].

The -NAO referring to the negative phase of the North Atlantic Oscillation, which possesses a rather high correlation with cold, snowy weather across the eastern United States.  A negative phase of the Arctic Oscillation also has correlation to more eastern U.S. troughing and coldness.

A look at the recent indices of these is illustrative, along with a peek at their short-term forecasted trend.

NOTE:  All the following graphics are courtesy of the Climate Prediction Center.

Observed Arctic Oscillation Index

An inspection of the observed AO index already shows a high correlation to recent weather conditions, with the -AO from July into early August being associated with unseasonably chilly summer conditions across the great Appalachians.

Note that the flip to a +AO, from mid-August through the month of September, also possesses a rather high correlation to the local change into humid, wet, and warmer conditions.

The return to a highly -AO during October was accompanied by a chilly month, with near to below average temperatures being widespread across the region.

The most recent index has mostly featured a +AO, and conditions in November have been mild compared to average.

Observed and Forecasted AO Index

With the above in mind, the forecasted trend is for the AO to go highly negative heading into late November and early December.  Could that mean a BIG pattern change to colder, snowy weather?

Let's look at the North Atlantic Oscillation, and see if it follows the AO trends.

Observed North Atlantic Oscillation Index

The observed NAO index pattern looks amazingly similar to the AO, and has also shown a high correlation to weather conditions observed within recent months.

The -NAO has been associated with cooler than average temperatures, and the +NAO intervals have been observed during periods which had near to above average temperatures.

The downward trend during November, toward the current -NAO, however, has not been associated with colder conditions.

Sometimes there is a small lag time ( otherwise, another forcing like +ENSO may be acting to cancel its effect ).

Lets now see what the forecasted trend is on the NAO.

Observed and Forecasted NAO Index

The NAO index is also forecasted to go negative during late November and early December.  So the score is 2-0 for a turn toward colder conditions ( 2 for / 0 against ).

[ NOTE: The AO and NAO are not predictable more than a few days to a couple weeks in advance, due to various reasons, and are not as good of a forecast indicator for longer ranges as they might appear to be ].

Let's keep marching onward to the Pacific North American ( PNA ) index.  A +PNA tends to be associated with eastern United States troughing, and western U.S. ridging, while a -PNA tends to help force a RIDGE in the eastern United States.

Observed Pacific North American Oscillation Index

As can be seen by the observed PNA index, there is also a good amount of correlation between cooler local conditions and +PNA formation, and warmer local conditions and -PNA development.

Lets see what the forecasted PNA is to do in coming weeks.

Observed and Forecasted PNA Index

The PNA is forecast to go positive during late November-early December, which again would support a change toward colder local conditions ( Score: 3 to ZIP ).

So there appears to be something upcoming.

A major pattern change toward eastern United States troughing, and colder conditions during the Thanksgiving Holiday to December 1 period.

Lets now look at the forecasted EPO index, since a strong +EPO tends to be associated with strong zonal flow across the Pacific, which is likely to spread mild, oceanic air into the United States. 

A -EPO is desired for colder air within the eastern United States and, as previously noted, when a --EPO ( strongly negative ) phase couples withstrongly negative phase of the NAO ( --NAO ), a prolonged arctic outbreak into the eastern United States is often likely during winter.

Forecast of EPO and WPO

Ensemble forecast model runs at NCEP ( the National Center for Environmental Prediction ), predict that the EPO will go strongly negative during the week of Thanksgiving.  So this is yet another factor favoring a major pattern change during the holiday period.

A unknown then becomes, what impact will the forcing from a moderate to borderline strong +ENSO have on these above teleconnections.

Remember, waves emitted from each will have to interact together, with the resultant outcome generating the type of weather conditions to be observed over any given area.

Ideally, a near neutral to weakly positive ENSO ( +/-ENSO ) is better for colder weather in the eastern United States.

The +MJO noted above, within the teleconnection list, refers to an active phase of the Madden-Julian Oscillation, with positioning that allows input of energy into the polar westerlies.  The MJO is an oscillation which travels through the tropics of the globe, with a 30 to 60 day frequency. 

The MJO influences the North Pacific jet stream, which in turn can help develop a PNA pattern.  If a +PNA develops, this makes downstream trough formation more likely across eastern North America, to again show how various wave supported oscillations can work together to impact conditions FAR away from where they actually develop.

Another important factor, that is itself relayed to the atmosphere and transfered in wave form, is mid to high latitude snow cover.

The covering of snow across high latitudes early in a season can be very important to the evolution and development of winter patterns.

Lets look at the current snow cover status across the Northern Hemisphere.

Northern Hemisphere Snow & Ice as of November 18

A 30-day loop of Northern Hemisphere snow cover changes:
http://www.natice.noaa.gov/ims/loop/nhem-1mo-loop.html

As the above well illustrates, REAL wintry conditions have been on the other side of the North Pole and across Alaska.  Rapid and huge increases in snow cover have occurred across Asia, deeply into China during the past month.

By contrast, the snow field has had a difficult time claiming and maintaining its hold on the southern half of Canada, and has been essentially absent from the lower Forty-Eight of the great USA, outside of the higher elevations of the Rockies, Cascades, and Sierras.

This does not initially bold well for a harsh winter in the eastern United States, but there is still time for rapid expansion and coverage of the white stuff into the Thanksgiving to Christmas holiday period.

The amount of snow cover across Asia can not be ignored, since a cross-polar flow could work to transport bitterly cold air masses into Canada, amid the long arctic nights, and eventually threaten the United States.

That would require our teleconnections to get into the right phases, such as a -NAO / -AO with a +PNA and -EPO.  If phasing were then to occur with a +ENSO enhanced sub-tropical jet stream, the stage could be set for some of the most severe winter conditions since the 1970s and 1980s.

[ From an ecological perspective, we NEED to have at least one SEVERE cold wave, with minimum temps dipping to -20 F below zero or lower, in order to kill out the Hemlock Wooly Adelgids ( Adelges tsugae ) which are threatening to drive our majestic, beloved, and so precious Canadian Hemlock ( Tsuga canadensis ) trees into extinction ].

How snow cover can alter the course of a winter will be highlighted in my Historical Climatology section below.

Despite the above favorable indices, toward a colder pattern by Thanksgiving, the generally favored and superior European Medium Range Forecast Model is not yet showing a definitive push of cold air, with establishment of a long-lived wintry period.

European 10-Day Forecast Charts - Nov 18

[ The RED lines on the panels above are the 500 mb geopotential heights, while the BLACK lines are the surface isobars.  A dip in the RED lines signifies a trough, while a bulge indicates a ridge, much like one observes when reading a topographical map.  A trough in the atmosphere is like a great valley, while a ridge is analogous to a great mountain ].

Here is the European Model Run for November 19 at 1200 UTC, for a comparison with the model run of 24-hours ago ( above ):

European 10-Day Forecast Charts - Nov 19

[ Note the differences between these two model runs ].

European 10-Day Forecast Charts - Nov 20

Note in the most recent model run above, from 1200 UTC November 20, that the longer range is becoming progressively colder, relative to the model runs of 24 to 48 hours ago.

It will be VERY interesting to follow the European model ( as well as others like the GFS, GEM, and UKMET ) through the next five to ten days, in order to see IF it begins to strongly reflect the wintry nature suggested by teleconnections highlighted above.

If it does not, then it could mean that the +ENSO may, indeed, be the BIG DOG and dominant WAVE-form to rule the 2009-10 winter season.  Time will surely tell.

Updated - TIME IS Telling

Time is indeed telling, as each new forecast model run of the European ( as well as others like the GFS, GEM, and UKMET ) are growing increasingly cold and wintry looking by the Thanksgiving Holiday.  Check out the latest run from this morning ( 1200 UTC on November 21 ).

European 10-Day Forecast Charts - Nov 21

The European is now showing the first widespread snow accumulation of the season, from the highlands of the southern Appalachians into New England, during the Thanksgiving-Black Friday period of this coming week ( especially along the western front range of the mountain chain ).

This is being echoed by the GFS and other models, with details of the event ( of course ) yet to be worked out.

Perhaps most significant, this looks to be part of a MAJOR pattern change that will present the region with a jet stream phased winter storm threat by the end of November.  Stay tuned!

[ An interesting point, made numerous times by forecaster Larry Cosgrove, of WeatherAmerica, is that the +ENSO enhanced sub-tropical jet stream is running much farther SOUTH than is found during more typical El Nino events of moderate nature.

Climatology agrees.  For example, instead of hammering southern California, the sub-tropical jet stream has been running south of the Golden State and passing across the Gulf of Mexico and up the Southeastern coastline.  This could be a VERY significant factor, with vast implications on the upcoming winter, should this trend continue ].

Update On The Update - November 28

The Thanksgiving-Black Friday event ended up being very weak, with generally 1" or less of snow across the High Knob Massif and higher elevations of the Mountain Empire.

Eagle Knob of High Knob - November 27
Image courtesy of Steve Blankenbecler

Just enough snow to cover the ground and high elevation roads, with a light coating of RIME on the trees.

COLD temperatures did allow some snow to linger across northern slopes of the massif into November 28, with early MINS in the 10s to lower 20s within colder basins and valleys.  BRRR!

The lack of local snow was thanks to a LACK of any Great Lake moisture, with very limited low-level moisture for the upsloping to work on ( despite ROARING winds which actually carried some of the snow across the windward side of the crest shown above, depositing less there ).

Some LAKE moisture allowed for 2"-5" snow accumulations to occur above 2500-3000 feet across the central-northern highlands of eastern West Virginia.

Despite the lack of snowfall so far during the 2009-10 season, the MAJOR pattern change noted above is still underway and will become apparent as December gets going.

All major indices are even more supportive than previously shown, with the latest -AO prediction being a classic example:

Observed and Forecasted AO Index

A strongly negative Arctic Oscillation is being forecast to occur into early December, to correlate with high latitude blocking and a southward suppression of the arctic-polar jet streams.

Get ready for some BIG changes!


2 ). Milder, Less-Snowy Winter

For those wishing for a mild, less snowy winter within the High Knob Landform, southern Appalachians, and across the eastern United States in general, the following teleconnection phase combos would be nice:

+AO
+NAO
-PNA
+EPO
++ENSO 
-A lack of snow cover across 
eastern Canada and the NE U.S.A

I will not go through each of these, as the impacts are just opposite to those noted above for their other phases.

However, I will note some interesting examples below in my Historical Climatology section.

I will also note that the ++ENSO refers to a strong epsiode ( strong El Nino ), such that warmth is more often than not dominant over coldness during the winter season relative to average.

That makes snowfall near to below average across the western front range and foothills of the Appalachians ( westward and northward of the HKL and Tennessee Valley Divide ).

In such a case, the train of waves rippling outward from a STRONG El Nino acts to overwhelm the other waves over any given area ( at least, in the seasonal MEAN ). 


The Bottom Line......

So what is the Good News?

It is that we have identified many major atmospheric teleconnections which impact global and regional weather conditions.  These can give us a guide to go by, but most are not as consistent and predictable in advance as are ENSO espisodes ( i.e., El Nino and La Nina )!

Once running, however, some have long-time scales ( like the PDO and QBO ) and can help generate a known setting within which ALL the vast array of other wave disturbances play.

Through long-term, daily weather observations and research a climatology has evolved to help guide us into the uncharted future.

I will highlight this more below.

So what is the Bad News?

The bad news is that the future is UNCHARTED ( with very few exceptions ) beyond the short-term.

I really do not want to focus alot on the bad news, since I always try to keep a positive outlook.  But the BAD news is that the state of our science, as I've noted before, is simply NOT GOOD ENOUGH to detail weather conditions for any given location more than a few days to a week in advance. 

Although 7 to 10 day forecasts look nice on TV, most are simply for appearance, as DAY 7 from DAY 1 will almost always be much different, sometimes radically so, from that which was initially predicted on DAY 1.

Thus, anything beyond a week is into the realm of pure fantasy, and guess work, when it comes down to giving any significant details ( predictability actually begins getting PUSHED HARD at 3 to 5 days ).

Its not a forecaster's fault, unless the forecaster blatantly tries to act like they always know what is going to happen a week from now ( i.e., just for the SHOW of acting or lack of knowledge ).

It is the combination of all the waves rippling through the atmosphere, as I've highlighted previously, from ALL the many known plus UNKNOWN disturbances, that takes initial forecast model input and drives it into pure CHAOS ( and that assuming the initial input data is GOOD ).

In fact, that is the definition of chaos, as the initial input increasingly departs from reality over time and creates a highly UNSTABLE solution which is not predictable from the starting point ( i.e., the final solution ends up being radically different from actual, real conditions ).

[ In reality, the initial INPUT data into forecast models is FAR too limited in both space and time to even begin to fully handle the complete state of the atmosphere.  Thus, forecast models often struggle with just predicting conditions during the upcoming 24 to 48 hours ].

That MUST be understood by everyone, since too much is often expected of forecasters ( despite all the fancy looking graphics of today ).

On the other hand, forecasters must not assume too much and be willing to take responsibility for relaying to the general public that the state of our science is simply NOT yet good enough to KNOW exactly when and where a tornado will strike, for example, or what conditions will be like where you live far into the future.

It's like a young couple planning a wedding asking:
What will the weather be like at 3 PM in the afternoon a month from this Sunday? 

The HONEST answer, it is NOT POSSIBLE to know. 

Period!

Historical Climatology

Tussock Moth Caterpillar ( Lophocampa caryae ) - High Knob
Photograph by Roddy Addington - © All Rights Reserved.

The Tussock Moth Caterpillar above was captured by Roddy on High Knob during a day in which he said, "it looked cold, and out of place."

Weather conditions can also be out of place for the season during periods with many competing forces, fighting to control the great atmospheric domain.

The current global warming cycle on Earth, which is very REAL, in combination with a large-scale forcing factor like the +ENSO teleconnection, weights models used by the Climate Prediction Center too much, in my own personal opinion, and skews their needed objectivity away from the best possible solutions.

Here are the official forecast maps from the Climate Prediciton Center for the upcoming winter season:

[ These initial forecast maps were made on October 15, 2009 ]

December-February Temperature Trend
Courtesy of the Climate Prediction Center

The CPC official trend on these graphics calls for below average temperatures and precipitation across the local mountains. 

December-February Precipitation Trend
Courtesy of the Climate Prediction Center


[ UPDATED forecasts made on November 19, 2009 ]

December-February Temperature Trend

An inspection of the new CPC map trends, reveals very little change since their mid-October forecast.

December-February Precipitation Trend

Here is a link to an extensive, detailed report on the current evolution, status, and prediction of ENSO ( El Nino ) that is updated with passing time:


Many forecasters like to use "analog" years, with similar upper air or surface conditions as observed during the present year ( leading up to a winter season ).

Historical climatology shows that they can, indeed, be helpful, but it also reveals that EVERY new season is different, with outcomes that end up being unique in space and time.

A look back at +ENSO episodes reveals the above, with each event being different, due no doubt to modulation by complex wave interactions via the myriad of atmospheric teleconnections and other factors which are running at the same time as El Nino ( with many positive and negative feedbacks among them ).

External forcing factors, not yet even mentioned, must also be considered, such as the currently long SOLAR Minimum ( lack of sunspots ) that generated the least sunspot activity in a hundred years during 2008 ( with a similar pace being observed during 2009 ).

In the MEAN, as climatology will eventually GRUNT out, the tendency during +ENSO periods has been for below average precipitation & above average temps across western slopes of the Appalachians during the time of maximum ENSO influence ( generally the December-February period of meteorological winter ).

Local orographics skew this, with the wettest, coldest, and snowiest conditions being across the High Knob Massif, and along the crestlines of the northwestern-southeastern flanks of the HKL into windward slopes of the Tennessee Valley Divide ( which includes the Cumberland Mountain arm of the HKL and the lofty terrain of its great Cumberland Gap National Historical Park ).

Although that could be said of any given cold season, the distribution of the precipitation within the lifting zone of the High Knob Massif, in particular, is skewed from the more typical SW-W-NW flow dominated regime toward its S-SE-E facing crests, basins, and slopes.

The favored zones being shifted due to more S-SE-E flow events and forced upsloping along those slopes of the sprawling massif.  This also includes southern-southeastern slopes of the adjacent Black Mountains, along the VA-KY border.

Total precipitation amounts ( rain + melted snow ) for the winter season generally end up being ABOVE average within these favored orographic corridors.

Above average winter precipitation is also favored during +ENSO episodes along the Blue Ridge, with spill over into the Great Valley during strong El Nino events.

By contrast, below average cold season precipitation amounts are more likely to dominate northern Wise County, and the central-northern portions of Dickenson and Buchanan counties, due to increased downsloping on S-SE-E air flow trajectories.

This sub-average precipitation regime of +ENSO episodes tends to increase toward the west and north of the Cumberland Mountains, into the foothills and bluegrass of Kentucky and West Virginia, as well as into the lowlands of the Ohio River Valley. 

The 1982-83 ENSO, which has been the strongest positive phase on record, was interesting in that it resulted in winter snowfall totals which were 100-150% of average from the High Knob Massif across the Great Valley of northeastern Tennessee-southwestern Virginia.

This trend continued eastward across the Blue Ridge into the Piedmont, with seasonal snowfall totals which ended up being 200% of average around the Nation's Capitol.

Snowfall totals within the Clintwood to Wise corridor were 90-100% of average during the 1982-83 season, with a decrease to only 50-90% of average being observed across most of Kentucky and West Virginia.


A Mega-Snowstorm
Risk With +ENSO?

From a long-term climate perspective, it should also be noted that 3 of the 4 largest snowfalls of the past 60 years across the western front range of the Cumberland Mountains occurred during a +ENSO phase of the oscillation ( El Nino ); although, only 1 of those occurred with a strong El Nino within the critical 3.4 sector of the equatorial Pacific Ocean.

Thus, a +ENSO phase is somewhat suggestive of an increased mega-snowstorm risk, despite the general El Nino trend of near to below average seasonal snowfall to the west and north of the HKL and Tennessee Valley Divide.

[ The great snowstorm of November 1950 occurred during a negative ENSO ( La Nina ) phase ].


Harsh Winter's Occurred 
During Weak +ENSO Phases

The year of 1976 has been batted around as an analog year to the present event, however, it was much different.  Only marginal ENSO conditions occurred during the 1976-77 season, with above average sea surface temperatures being generally restricted to the El Nino 1-2 regions near the South American coast.

The 1977-78 season, however, did display a more typical and expansive region of positive sea surface temperature anomalies into the central equatorial Pacific Ocean.

These late 1970's winter seasons are, of course, legendary for their harsh winter conditions, with brutal cold and mean snow depths reaching 42"-48"+ across upper elevations of the High Knob Massif ( during just the seasonal buildup of the snowpack ).


The Importance of 
Higher Latitude Snow Cover

The importance of placement of high latitude snow cover was taught during the back to back winter seasons of 1995-96 and 1996-97.  These two winters generated the largest snowfall differences ever documented locally.

The 1995-96 winter established new seasonal snowfall records for Virginia, with 124.2" in the town of Wise and more than 200" at the summit level of the High Knob Massif.

The 1996-97 season was, by dramtatic contrast, a grand snow BUST with 100.2" LESS snow in Wise ( only 24.0" fell during the entire winter ).

The NAO was in its negative phase during both winters, with a prolonged -NAO showing up for the first time since the middle 1980s ( complete with abundant high latitude blocking ).

The SOI classification scheme places the 1995-96 and 1996-97 winters into the neutral ENSO bracket ( so that ENSO was considered to basically be a non-player during both seasons ).

The big player, as it turned out, was development and distribution of snow cover across Canada.

During the great 1995-96 season, an unusually deep field of snow developed across southeastern Canada and the northeastern United States by late autumn of 1995.  This set the stage for record breaking snowfall across the western slopes of the Appalachians, as the polar vortex became established over SE Canada.

The persistent location of the polar vortex kept the baroclinic zone ( the zone of max thermal contrast ) in a position to feed energy and moisture into one developing wave disturbance after another, with cold air in place to support abundant and heavy snows ( especially along the W-NW-N slopes of the mountains ).

During the next winter, by contrast, early season snow cover formed across western and south-central Canada, with expansion southward into the Rockies and Plains by late autumn.

The temperature contrast between the snow field and bare ground to the south, set up the baroclinic zone in a manner that held the storm track northwest of the Appalachians.  This kept the region within the rainy, warm sector of approaching wave disturbances, and dry slotted the area in their wake ( with often no snow at all despite influxs of cold air ).


LINKS to Winter 2009-10 Forecasts

Note: The inclusion or exclusion of anyone in the list below is not an endorsement, nor a rebuke, of their work, but merely offers different perspectives from different places across the nation.

Western North Carolina 2009-10 Winter Forecast:
http://www.booneweather.com/Fearless+Forecast

Washington, D.C., Area 2009-10 Winter Forecast:
http://voices.washingtonpost.com/capitalweathergang/2009/11/capital_weather_gang_2009-10_w.html

Weather Advance 2009-10 Forecast for USA:
http://www.weatheradvance.com/winter-2009-2010-forecast

NWS Forecast Office - La Crosse, Wisconsin:
http://www.crh.noaa.gov/arx/?n=winter200910outlook

Dean Grubbs - Raleigh, NC., Climate Examiner:
http://www.examiner.com/x-17371-Raleigh-Climate-Examiner~y2009m11d24-Winter-200910-Old-man-winter-returns--part-2

Monday, November 2, 2009

WETNESS Rules The High Knob Massif


Big Cherry Basin of the HKL Highcountry
Photograph by Wayne Browning - © All Rights Reserved.


October is climatologically the driest month of the year across the great High Knob Landform ( HKL ), and western front range of the Appalachians.

Not so during 2009, as October merely marked another notch in Mother Nature's wetness gun!

Its actually been more like a HOSE in the High Knob highcountry, where wetness has RULED the massif for the better portion of the past year.

My friend Gary Hampton, superintendent of the Big Stone Gap Water Plant, and his fine staff, have now measured more than 80.00" of total precipitation during the past 12-months at majestic Big Cherry Dam of the High Knob Massif.

Here's a Monthly Breakdown.

Big Cherry Dam of the 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"
Oct 1-Nov 1: 6.00"

2009 Total: 67.60" ( M )
12-Month Total: 80.45" ( M )

There are numerous things interesting about this hand-measured precipitation data. 

First, its much more accurate than automated gage data but is significantly less than what has ACTUALLY fallen from the heavens, and accumulated at Big Cherry Dam and across its lofty basin ( water elevation of Big Cherry Lake being 3120 feet above mean sea level, at full pool, lowest in the main Big Cherry Basin ).

Although the Dam area is now monitored 24-hours per day, 7-days per week, and 365-days a year for security purposes, it is not possible for Gary and his staff to hand-measure precip every day.

During 2009, and the past 12-months, there has been at least 3.00" of evaporational losses from the rain gage between hand measurements at Big Cherry Dam ( this based upon evaporation losses observed under ideal conditions at my National Weather Service station, which I use as a "control" site ).

So in reality, more than 70.60" of precipitation would have been measured at Big Cherry Dam during 2009, and more than 83.50" during the past 12-months, if it had been possible to measure every day by hand. 

Thus, to be honest an ( M ), for missing moisture, must denote the above data set.

Majesty of Mixed-Hardwood Forest
Photograph by Wayne Browning - © All Rights Reserved.

So as farewell is bid to the glorious autumn color show of 2009, as so well documented by the professional quality photography of my good friend Roddy Addington, the above notation of missing moisture for the Big Cherry Dam observation site gets it on equal footing with other places that measure every day ONLY if the evaporational losses ( of approximately 3.00" ) are added. 

[ For Roddy's great photography reference the following: 

For mid-upper elevation measuring sites in the mountains, however, the ultimate reality is that even by hand measuring precipitation EVERY day there is still going to be a NET LOSS of recorded values due to wind induced rain gage undercatches.

I was blessed to learn about this aspect of wind induced gage losses in rain, and especially in frozen precipitation forms, by personal communication and instruction from Dr. Boris Sevruk. 

Boris is most likely the world expert on this aspect of climatological measuring and worked many years amid the rugged Alps of Switzerland to document and learn how winds play havoc with rain gages, their design, and placement.

Although Boris is now retired, he is nothing less than a legend in his field with an outstanding record of teaching, research, and contributions to many diverse climatological studies: http://www.iac.ethz.ch/people/sevruk/index

The way this world is today if you wish to truly learn something you should seek out the BEST of the BEST and, IF they are willing to teach, you will be blessed!  Boris WAS WILLING and I thank him so much.  I was blessed by the humble, sincere, and good hearted nature of Boris Sevruk. 

A truly RARE breed in this modern, ego-centered world, whom I will not soon forget ( I can only imagine what he may now do in his retirement! ).

Boris and others in the world have developed mathematical formulas that can be applied to gages based upon observed wind speeds, that clearly show the significance of precipitation gage undercatches.

Although I do not apply the formulas to my reported High Knob Massif sites, I have used them enough to know that what ever is measured and obtained, via adjustments for evaporational losses, will still result in totals that are well below what really falls.  This being especially true along exposed, convex crestlines, and other open sites where winds are either turbulent, rising, strong, and/or all of the above!

Eagle Knob of High Knob Massif
Fiery Maple At Nearly 4200 Feet Elevation
Photograph by Wayne Browning - © All Rights Reserved.

Beautiful autumn colorations, such as above, can be short-lived on the Eagle Knob of High Knob where my weather station sits at 4178 feet above mean sea level.  Although not the highest peak in Virginia, the location is one that finds air almost always rising and in turbulent motion.

A placement of rain gages in MANY different locations generates varying totals, which Boris noted makes it especially hard to obtain accurate measurements of true precipitation falls.

That the above is true becomes SO VERY OBVIOUS when winter settles into the highcountry!

High Knob Massif Crest Zone
Eagle Knob of High Knob Massif Wind Effects
Steve Blankenbecler Image - © All Rights Reserved.

The above image, courtesy of my friend Steve Blankenbecler, illustrates how northerly winds blowing across the summit of Eagle Knob have swirled the snow with vortical suction motions into convergent rows, piles, and deep zones, all the while sweeping the ground bare within adjacent locations.

Although the above setting was impacted by the communication tower and chain-link enclosure, the same type of effects occur around trees and other natural features along the crestlines.

During many past snow events I have recorded for my records that snow depths along the crestlines varied, "from bare ground to feet in drifts."  While that might sound a bit crazy, it is indeed the reality, true, and honest!

What may not appear to be obvious, from the above, is that highcountry winds impact RAIN in much the same way.  It's just that one can not see how the rain accumulates, drifts, and blows around like snow!! 

While it is true, that rain is not perturbed as MUCH as snow, or frozen forms, it IS perturbed as anyone can prove by placing small containers near to the ground in different locations.  When winds howl, and rains fall, each container will almost certainly collect varied amounts for the different locations.  Yes, much like snow, the rain blows, drifts and accumulates much more in some places than others.

High Knob Massif Crest Zone
Endemic Southern Appalachian Northern Hardwoods
Photograph by Wayne Browning - © All Rights Reserved.

When looking upon the richly varied forests of the High Knob highcountry, as illustrated by the vast array of colorful species above, one may not think about such things as drifting rains and snows!  And may not think about how they have played important roles in establishing all the ecological niches that are exploited by more species, from beneath the forest floor to its tippy-top, than ANYONE today even knows are there!

But in fact, the situation is SO MUCH more complex, since up in the highcountry wind speeds nearly always INCREASE with the onset and continuation of precipitation.  For valley dwellers, of which the majority are, you may know that wind speeds typically decrease after precipitation begins in non-convective settings.

For here, I am mainly talking about the orographic forcing season, from late autumn through spring, when large-scale storm systems develop pressure gradients that generate WINDS to push against the topogrpahy.

It is during the orographic forcing season that the truly great ones, like the High Knob Massif, Mount Rogers, Roan, Mitchell, Mount LeConte, Mount Porte Crayon, and numerous others
FLEX their mountain MUSCLES.

In places like the Big Cherry Basin it is denoted by an UP-spike in their measured precipitation amounts during the forcing season relative to other locations not impacted by strong orographics, or subjected to mean negative forcing ( i.e., subsidence or sinking with downslope trajectories ).

In fact, for measurement purposes, high basins and coves tucked away amid the highcountry are the BEST places to set up precipitation measuring sites in upper elevations. 

Southern Appalachian Mixed-Mesophytic Cove Forest
Photograph by Wayne Browning - © All Rights Reserved.

The many basins within the sprawling High Knob Massif offer unique opportunities, as do locations like the relatively sheltered cove tucked amid the lofty north slope of Mount LeConte in the Great Smokies ( perhaps the BEST measuring site for such a HIGH elevation in the Appalachians ).

The higher convex crestlines are therefore NOT where one would choose the best places for measuring precipitation, since in order to do even partially good it requires changing rain gage locations with shifting wind directions ( e.g., the southeast side of the crest for a NW wind, the northwest side of the crest for a SE wind, the northeast side of the crest for a SW wind, the southwest side of the crest for a NE wind ).

The above is not currently possible, but tilting rain gages that tip with changing wind directions and speeds are an experimental possibility for improvement toward what I just described. 

Not a solution, since winds rise upwards, often at accelerated speeds across crestlines, such that many precipitation elements are actually carried completely across and fall leeward onto high slopes, into high basins, or simply evaporate away with sinking, or subsidence, along narrow crested ridges.


The Lifting Zone

Nestled against northern slopes of the High Knob Massif, the remnant highcountry of the HKL, is the lovely City of Norton.

The wettest town or city in Virginia as verified by data scans of ALL available resources.

Norton is proving that once again during 2009, and the past 12-months, with enhanced precipitation amounts via a general mean of rising air amid the lifting zone created by the sprawling massif.

A most interesting situation, given periods of significant sinking, or downsloping, which also subtracts precipitation from the city on south to southeast air flow trajectories ( at least under typical conditions, as there are some notable exceptions ).

My friends, Superintendent Tommy Roberts and his great staff, diligently measure precipitation by hand every day just like clock work at Norton WP.

Here's a Monthly Breakdown.

City of Norton Water Plant
Elevation: 2342 feet

2008
November: 3.68"
December: 8.58"

2009
January: 7.34"
February: 3.27"
March: 5.24"
April: 5.13"
May: 9.72"
June: 7.95"
July: 5.46"
August: 5.19"
September: 6.08"
Oct 1-Nov1: 4.68"

2009 Total: 60.06"
12-Month Total: 72.32"

A comparison between the Big Cherry Dam and Norton WP data sets reveals some interesting variations.

Much more rainfall was measured in Norton ( 5.16" more ) during May-June than at Big Cherry Dam, while much more rain fell at Big Cherry Dam during July-September ( 7.86" more ) than in Norton. 

These differences being concentrated mostly during the rather chaotic convective season, with variations in the formation and propagation of showers and thunderstorms along the massif.

At some location, or locations, in between these two data points ( and they are only point measurements ) there was likely more total rainfall than measured in either rain gage, as well as less, to generate a greater spread in "warm season" rainfall than suggested by just the Big Cherry and Norton stations.

In general, the most steady difference can be seen during the orographic forcing season of November-April, ( sometimes this can include May and/or October ), with the Big Cherry Dam measuring point consistently receiving more precipitation each month than the City of Norton. 

This despite the greater evaporative and wind induced rain gage losses at the higher elevation Big Cherry site ( i.e., the difference between Big Cherry Dam and Norton was greater than indicated by the rain gages since the gage at Big Cherry had loss of moisture due to evaporation between hand measurements and greater forced losses due to stronger winds blowing across its opening ).


Powell Valley of the High Knob Massif

Anyone from this area, or traveling through the region along our famous Country Music Highway ( U.S. 23 ), knows that the Little Stone Mountain Gap passage in the High Knob Massif often marks a major weather change zone.

Amid "quiet" times it may "only" be marked by such scenes as below, which was beautifully captured in a series of pictures by Ron Flanary during early October.

Lingering Inversion - Powell Valley of High Knob Massif
Photograph by Ron Flanary - © All Rights Reserved.

My good friends Elizabeth & Addison Stallard live beneath the fog layer above, within the majestic Head of Powell Valley, and have been keeping weather records since the 1970's.

These "youngsters" have documented the good, the bad, and the ugliest of weather conditions, and deserve no less than a GOLD metal for their efforts over all these many years.

During 2009, and the past 12-months, they have measured the following monthly totals with nary a missing day! 

Head of Powell Valley of High Knob Massif
Elevation: 1945 feet

2008
November: 3.30"
December: 7.50"

2009
January: 7.10"
February: 3.06"
March: 4.84"
April: 4.72"
May: 8.37"
June: 6.37"
July: 5.63"
August: 5.27"
September: 6.33"
Oct 1-Nov 1: 4.31"

2009 Total: 56.00"
12-Month Total: 66.80" 

Thanks to Elizabeth & Addison Stallard we have an insight into the local climate that simply would not exist without their exemplary records!

Measuring every day near the other end of Powell Valley, amid the great South Fork Gorge opening at the Big Stone Gap Water Plant, my friend Gary Hampton reports a little more than the Valley Head, with just over 56.00" during 2009 and nearly 68.50" in the past 12-months.

November 4, 2009
Upper Tennessee River Basin
Looking to South Fork Gorge of Powell River Basin
Majestic Morning Light In Powell Valley of HKL
Photograph by Roddy Addington - © All Rights Reserved.

[ Majestic morning light illuminating a cornfield at the end of the growing season was beautifully captured by Roddy Addington early on November 4.  Rugged mountain walls rising upward in the background guard the opening of South Fork Gorge ].

The highcountry of the Big Cherry Basin, spreading out above Powell Valley, has received more than a foot ( 12-14" ) of measurable precipitation beyond that observed amid the beautiful Valley during the past 12-months ( MUCH more when allowing for evaporation losses, of at least 3.00", and wind generated rain gage undercatches in both rain & snow ).

Of course, that is just PRIMARY precpitation!

When factoring in FOG drip from trees and the gorgeous but very important RIME deposition upon trees, the addition of SECONDARY moisture sources across the High Knob highcountry has truly generated a MAJOR bonus of moisture which is FAR greater than that endured by residents living amid the rugged mountain walls of Powell Valley.

[ For STUNNING Roddy Addington photography and to obtain additional information about RIME please reference:  Introduction To RIME In The High Knob Massif ].

This is WHY the High Knob Massif is a true WATER CAPTURING WONDER for this latitude in Virginia and the Appalachians.  The numbers simply DO NOT lie and reveal a great many things which are key to the vast biodiversity & karstification of this truly incredible and ancient landscape of the HKL.

It's time we all learn!


Current Wetness Ranking Within The HKL

Good, consistent, weather records reveal that 2009 and the past 12-months have been wet, but NOT nearly as moist as the wettest documented since just the late 1970s-early 1980s ( a relative, minute flicker amid the vastness of time ).

The wettest 12-month period on record in the city of Norton had more than 80.00" of total precipitation during the 1993-94 period ( 79.29" in the gage, but with notable moisture loss during the rather harsh winter in deep snowfalls that the smaller rain gage, used at that time, could not hold ).

This suggests that the 1993-94 period had 8.00-10.00"+ of precipitation above what has been observed so far during the past 12-months, with MAX totals of between 90.00" to 100.00" within the High Knob Massif verses the 80.00" to 90.00" max amounts attained since November 2008.  

IF November and December of 2009 are VERY wet, this year has at least a shot at becoming the wettest locally observed during this relatively short record period ( of 32-years ).  However, the odds are against it being that WET, unless this November can pull it out, since the wetness of December 2008 will drop out of the 12-month interval after December 2009 begins.  Only time will tell.

High Knob Massif
Upper Tennessee River Basin
Big Stony Creek of Clinch River Basin
Mountain Fork Backcountry of Big Stony Creek
Photograph by Otis Ward - © All Rights Reserved.

[ My friends Otis & Nancy Ward contribute much more than beautiful pictures, as they have also measured precipitation in the Robinson Knob community of the High Knob Massif for a number of years.  The driest month observed there during the past 12 was February 2009, with 4.05" of precipitation.  They were among the original founders of The Clinch Coalition ].


Outside The Lifting Zone 

The true significance of the High Knob Massif precipitation regime can be seen by an inspection of monthly totals from outside of its orographically forced lifting zone, where air flow trajectories are often impacted by downsloping leeward of its highcountry.

That such impacts should be felt is not surprising, given that if one sat the southwestern base of the High Knob Massif over the town of Wise you would have to drive all the way northeast to the town of Clintwood in order to reach its other side.  Just think about how many typical ridges and hills are passed along that distance!

Likewise, if the base of the mountains on the right side of Roddy's gorgeous cornfield photograph were placed over Red Onion Mountain, on the Wise-Dickenson border, the other side of the massif would reach all the way across to the Dickenson-Buchanan border ( along a W-E trajectory ).

When standing at Powell Valley Overlook in Little Stone Mountain Gap, the distance across to the other side of the massif along a NNW-SSE trajectory to Hanging Rock Recreation Area in northeastern Scott County is analogous to traveling from Elk Garden in Russell County to Glade Spring in Washington County.

The distance between the north base of the High Knob Massif at Ramsey, in Wise County, and it's southern base at Ka, on Big Stony Creek in Scott County, is the same as traveling from downtown Lebanon in Russell County to south of the North Fork of the Holston River in Washington County.

We are NOT dealing with any typical mountain here, as the gifted, talented, and sweet Gladys Stallard recognized so many years ago in her wonderful wildflower journeys and nature writings with award winning author, columnist, and dear companion
Gaynelle Malesky.

[ Beloved Gaynelle S. Malesky passed in September 2003 at the age of 92 and leaves an impressive legacy of poems and columns.  Gaynelle & Gladys wrote nature columns in the Coalfield Progress newspaper for more than 30 years and were the first writers, whom I remember, to distinctly recognize the unique size, topography, and nature of what
they knew as the great High Knob Mountain mass ].     

When adding the extended landform of High Knob, with its rugged northwestern mountain flank reaching southwest to magnificent Cumberland Gap National Historical Park, it becomes obvious that air flowing across a wide region is going to be impacted by the HKL and the remnant massif of its highcountry.

My friend Geneva Varner, Superintendent of North Fork of Pound Dam in northern Wise County, has been a diligent worker for the U.S. Army Corps of Engineers and dedicated NWS Cooperative observer for many years.

Here is a monthly breakdown of her hand measured precipitation totals during the past 12-months.

North Fork of Pound Dam
Elevation: 1675 feet

2008
November: 2.40"
December: 5.45"

2009
January: 5.55"
February: 1.85"
March: 4.48"
April: 3.17"
May: 5.07"
June: 6.83"
July: 5.26"
August: 4.55"
September: 6.06"
October: 3.66"

2009 Total: 46.48"
12-Month Total: 54.33"

[ Only the amount which fell after 8 AM on October 31 is not included ].

Although above average, the monthly precipitation totals at North Fork of Pound Dam are strikingly less than those observed at Big Cherry Dam of High Knob, and amid its adjacent lifting zone, via significant moisture robbing leeward of the HKL, and its remnant massif, on southerly air flow trajectories.

My friends Wayne & Genevie Riner report monthly precip totals that reflect much the same at their official NWS Coop station ( Nora 4 SSE ) atop beautiful Long Ridge of Sandy Ridge in the highlands of southern Dickenson County.

Golden Maples and Yellow Poplars - October 2009
Photograph by Wayne Riner - © All Rights Reserved.

Long Ridge of Sandy Ridge - Nora 4 SSE
Elevation: 2650 feet

2008
November: 2.35"
December: 6.18"

2009
January: 5.35"
February: 2.33"
March: 4.12"
April: 3.31"
May: 5.75"
June: 8.51"
July: 3.62"
August: 3.97"
September: 4.12"
Oct 1-Nov 1: 3.27"

2009 Total: 44.35"
12-Month Total: 52.88"

Long Ridge sits on the Tennessee Valley Divide, like the adjacent Wise Plateau, and monthly precipitation totals there are impacted by wind induced rain gage undercatches.  However, since these are not accounted for in standard reporting, the totals above are comparable to those observed at Big Cherry Dam of High Knob, except that the Big Cherry monthly totals also have evaporative losses ( as previously noted ). 

Wayne & Genevie measure every day by hand on Long Ridge, so there should be very little evaporative loss for Nora 4 SSE.

Autumn On Long Ridge of Tennessee Valley Divide
Looking Toward Northeast End Of Pine Mountain
Photograph by Wayne Riner - © All Rights Reserved.

When standing upon the highlands of southern Dickenson County, looking across the Russell Fork Basin toward Pine Mountain and Breaks Interstate Park, as so beautifully illustrated by Wayne's gorgeous autumn photography, it is rather difficult to think about moisture robbing on downsloping winds!

However, indeed, it is true that Long Ridge is within the rain and snow shadow of the High Knob Massif and its extended landform on WSW to SW air flow trajectories, with significant moisture extraction downstream of the High Knob highcountry. 

Again, the numbers do not lie with 27.57" less hand-measured precipitation on Long Ridge than at Big Cherry Dam during the past 12-months on just the RAW gage readings ( both sites have wind induced rain gage undercatches ).

In reality, of course, when adding in the 3.00" of evaporation losses at Big Cherry Dam, the true rain gage departure would find Big Cherry having had 30.57" more during the past 12-months.

That is a VERY impressive difference, given Big Cherry Dam is just 470 vertical feet higher in elevation than Nora 4 SSE.

The real cause, or literal forcing for this difference, not being directly due to the elevation of Big Cherry Dam, but rather to the atypically WIDE expanse of the High Knob highcountry and the forced lifting of air from the floors of the river valleys to above the summit level of the 4223 foot massif.

[ There is more MEAN lift on all air flow trajectories into the large High Knob Massif verses Long Ridge. When combined with moisture extraction and downsloping leeward of the High Knob highcountry, on moisture rich SW winds ( especially ), this results in less total precipitation on Long Ridge ].

Tennessee Valley Divide-Pine Mountain Ring Russell Fork Basin
Photograph by Wayne Riner - © All Rights Reserved.

The highlands along the Tennessee Valley Divide, upon which Long Ridge rests, in combination with the HKL and its remnant highcountry massif, collectively work to increase total moisture extraction farther northeast into the lower elevations of northern Dickenson and Buchanan counties.

[ This moisture robbing impact actually extends much farther northeast into southern West Virginia on SW winds, and into portions of eastern Kentucky on S, SE, and E winds.  It also has both an interesting and very important impact upon the upper Clinch River Basin, as will be noted later ].

This loss of precipitation on moisture bearing southerly winds is reflected by rain gage measurements, such as those made within the Haysi, Birchleaf, Sandlick, and Grundy communities.

Here is a monthly breakdown for the official NWS cooperative station at the Mountain Mission School near Grundy, within the Levisa Fork Valley of Buchanan County.

Mountain Mission School - Grundy
Elevation: 1170 feet

2008
November: 2.49"
December: 5.01"

2009
January: 4.75"
February: 1.28"
March: 3.81"
April: 2.66"
May: 8.24"
June: 3.44"
July: 5.34"
August: 3.69"
September: 2.95"
Oct 1-Nov 1: 3.48"

2009 Total: 39.64"
12-Month Total: 47.14"

The Grundy 12-month total is nearly 6.00" less than measured atop Long Ridge, and 33.31" ( 36.31" when factoring in the evaporative loss ) less than measured at Big Cherry Dam.

The long-term implications of these moisture differences are truly vast, given that they are not only significant but are consistently significant over the longer term.

For example, in the entire 45-year precipitation record of Clintwood there has NEVER been a January to December period with 60.00" of total precipitation.  Since 1964 the greatest Jan-Dec totals on record were 58.78" in 2003, 58.68" in 1989, and 58.30" in 1975.  FAR below the current January-October total for Big Cherry Dam of High Knob!

[ Steve Mullins, Superintendent of the Clintwood Wastewater Treatment Plant, and his staff measured 59.18" on the northeast side of town during 2003 ].

The greatest 12-month precipitation total in Clintwood reached 61.08" during the November 1988 to October 1989 period.  FAR below current one year precipitation totals within the High Knob Massif area, and 20-30"+ less than MAX 12-month totals.

Here's the Current Monthly Breakdown.

Clintwood 1 W NWS
Elevation: 1560 feet

2008
November: 2.51"
December: 5.81"

2009
January: 5.33"
February: 2.45"
March: 4.49"
April: 3.62"
May: 5.28"
June: 8.06"
July: 6.32"
August: 4.14"
September: 5.41"
Oct 1-Nov 1: 3.67"

2009 Total: 48.77"
12-Month Total: 57.09"

The current 12-month total in Clintwood is 15.23" less than measured in the City of Norton, and 23.36" less than Big Cherry Dam of High Knob ( -26.36" when adding evaporative losses ).

For this western Appalachian Front Range location of Clintwood, the ONLY way that this consistency could be maintained over such a relatively long period ( 45-years ) is by the domination, within the MEAN, of significant downsloping and moisture extraction leeward of the High Knob Landform ( and Black Mtn ) on moisture rich SOUTHERLY air flow trajectories!


Regional Precipitation Point Samples

An inspection of 2009 and 12-month precipitation totals from other parts of the region reveals some rather significant variations via a few selected point samples.

2009 Total / 12-Month Total

Virginia
Richmond: 31.64" / 39.22"

Charolettesville: 32.56" / 37.79"

Roanoke: 39.09" / 43.26"

Bland: 39.70" / 45.57"

Wytheville: 41.52" / 46.63"

Richlands: 42.01" / 48.52"

Blacksburg: 42.16" / 47.54"

Lebanon: 44.40" / 52.08"

West Virginia
Martinsburg: 28.91" / 34.98"

Beckley: 38.06" / 45.22"

Bluefield: 39.27" / 44.77"

Elkins: 46.65" / 55.55"

Tennessee
Tri-Cities: 40.03" / 46.53"

Knoxville: 50.79" / 63.18"

Kentucky
Lexington: 49.04" / 57.60"

Jackson: 49.31" / 59.20"

London: 50.05" / 57.56"

A general east to west increase in both 2009 and 12-month precipitation totals is evident across the state of Virginia, with extreme variations of up to 4 FEET of total precipitation ( rain + melted snow ) between wetter parts of the High Knob Massif and drier portions of central-eastern Virginia.

Martinsburg, amid the shadow of the northern West Virginia highlands, reports among the lowest 2009 and 12-month tallies, with 34.98" during the past year being 45.47" less than measured at Big Cherry Dam of High Knob ( 48.47" less when adding in the 3.00" evaporative loss at Big Cherry ).

Locations west of the Appalachian Mountains in Kentucky, from the rugged foothills into the bluegrass, have measured more total precipitation during 2009 and the past 12-months than most places subjected to the more direct, stronger downsloping and moisture extraction leeward of the HKL ( since the best robbing of moisture for them occurs on SE air flow trajectories which are less common in the MEAN ).

Large precipitation variations during the past 12-months can be seen between the City of Norton ( 72.32" ) and locations within adjacent Russell & Tazewell counties, at Richlands ( 48.52" ) and Lebanon ( 52.08" ), as well as in the Tazewell-Bluefield ( 44.77" ) area at the head of the Clinch River. 

These large annual precipitation extremes have been well documented ( since 1990 ) by NWS rain gages as being common, and generate the rather anomalous pattern of DECREASING moisture upstream, northeast of the HKL, in the ecologically diverse Clinch River Basin.

[ In most river basins precipitation INCREASES upstream into their headwaters.  This anomalous pattern within the Clinch River Basin, of significant decreases in annual precipitation upstream of the High Knob Massif, has played important roles ( perhaps THE KEY role ) in establishing its vast diversity of life forms via the presence of significant climatic gradients upon which diversity naturally depends.

As stated by Frank Kilgore, this could be "the missing link" in understanding the epi-center of biodiversity which has developed across the truly wondrous Clinch-Powell River watersheds of the Upper Tennessee River Basin.

Panorama Across Clinch River Valley to HKL
Photograph by Richard Kretz - © All Rights Reserved.
  
In this beautiful panorama by photographer and naturalist Richard Kretz, the HKL appears only as a long, blue swell upon the horizon of the majestic Clinch River Valley.