Tom Thomson's Artist's Camp, Canoe Lake, Algonquin Park

Aside from the stated justifications for these blogs as included in "Tom Thomson Was A Weatherman - Summary As of Now", there are some personal reasons why considerable effort is put into turning the draft Thomson book into a Blog. I am obsessed with learning - mostly focussed on the "nature of things" (Thank you David Suzuki) but really, anything is fair game. This endeavour helps to keep my meteorology sharp… use it or lose it.

The Tom Thomson experts that I know are a wealth of knowledge - something that became more obvious when the concept of this "Artist's Camp" blog was germinating. The weather in this painting is a patch of stable altostratus. That cloud was important to Tom as he included it with some difficulty behind the screen of trees. There are a few possible explanations for why that front-lit cloud was there but I will only depict the most likely below. The really interesting information comes from my Thomson friends.

On one occasion when I presented in Algonquin Park, September 1st, 2017, the staff had Tom’s tent set up in the Visitors Centre. I took a bunch of pictures and recorded the story behind Tom’s tent for my notes. It was thrilling to see his actual tent. The "balloon silk" was no longer white but the provenance of the tent via  Tom's friend Ranger Thomas Wattie of South River is very convincing. 

Thomson's tent was certainly not displayed as Tom would have had it assembled at camp. There was limited space in the Visitor's Centre but I was still exhilarated to be so close to something that Tom prized. My Tomson friend noted the greenish, tan colour of the tent on display and how it was so very different from the tent that Tom painted. I thought it was just the age of the fabric but perhaps Tom might have followed the advice from Horace Kephart's book "Camping and Woodcraft" which is detailed below. Page 41 describes why and how to dye a white tent to make "the tent less attractive to flies, and renders it less conspicuous in the woods, which latter is worth considering in some localities where undesirable visitors may drop in." 

My friend Roy MacGregor wrote in his 2010 book "Northern Light" that Tom Wattie's son Gord (then in his nineties) was persuaded by his nephew Cooper "that the family should donate their Tom Thomson belongings to the Algonquin Park archives." See Roy's book starting on page 172 for more details but the tent, sleeping bag and other camping items were listed by Ron Tozer of Algonquin Park on August 19th, 1998. Almost no one knew about these items except for Thomson's friend Tom Wattie. 

After selling a few paintings (including  $500 from the sale of Northern River to the National Gallery in 1915) and with some money coming in, Tom went shopping in the summer of 1915. He did not have access to the materials we enjoy for lightweight canoe tripping a century later. Fibreglass, kevlar and especially carbon canoes were not even a dream back then. Tom's canoeing adventures were decades before LED lanterns, water purifying kits, and a multitude of inventions that modern trippers deem essential. After all, every item had to be carried across the portage and I doubt if even Tom thought that portaging was fun…Tom wanted light and state-of-the-art gear (for 1915 at least)!

In late July or early August, 1915 Tom bought his new 16-foot Chestnut Guide Cruiser canoe, silk tent and other essential camping supplies. Tom used a $2 tube of cobalt blue oils with a standard marine grey to make his canoe truly unique. The "dove grey” colour would stand out from all of the traditional red and green canoes used by the lodges.  

 

The above classic photo shows Tom Thomson with a full load in his dove grey canoe and white silk tent in the background. The large Duluth pack at the middle thwart is heavy enough even with nothing in it. Tom had a lot of other gear as well. His painting box and supplies must have been buried in there somewhere. His tent had not yet been dyed. There is a story behind this photo that shows an enthusiastic artist about to embark on a couple of very creative years with his new gear. In fact, there is certainly a photographer behind every photo but that story is seldom told. Who took Thomson's portrait and did he wade out into the shallow water to do so? 

Tom paddled out from Canoe Lake on a long trip that likely went to the Magnetawan River, coming out at South River around Labour Day. Thomson then joined J.E.H. MacDonald (1873–1932) at MacCallum’s cottage on Go Home Bay to measure the walls for a series of seven commissioned decorative panels. Tom then returned to the park, where he remained until the weather drove him back to Toronto at the end of November.

Given the autumn colours, this painting would have been painted in October or early November before his return to the big city - back then the big smoke of Hogtown was Toronto the Good before it became Hollywood North. 

Thomson painted at least four images of his beloved tent. The following graphic includes the other three paintings of his brand-new silk tent.

At this point, I asked one of my Thomson friends to weigh in:

"The Artist's Camp has such a nice feeling to it - it makes me feel that I'd like to be there... One vivid memory is lying awake in the middle of the night with a full moon casting shadows of leaves on the tent - lovely. I would guess that the most likely location for this sketch was Hayhurst Point. It clearly is fall, with the yellow leaves on the birches and a few red leaves on perhaps some maple saplings. To me the light looks like morning - I think the alternate title Night Camp is probably incorrect. In fact, I can't think what in the sketch suggests night."

"I still think it is most likely a morning scene.  It's easy to imagine Tom setting up his tent with the door facing east to enjoy the sunrise and morning light."

As explained in previous blogs, morning light is more likely to be pure white. After a day of wind and convection stirring up particles into the lower atmosphere, the afternoon light takes on a distinctly yellow tone. Rayleigh scattering of the blue component of white light out of the direct beam from the sun is responsible for this subtle transformation. People are generally, subconsciously in tune with such phenomena without thinking of it. 

Artist's Camp, Canoe Lake, Algonquin Park
Alternate title: Night Camp Fall 1915
Oil on wood panel 8 5/8 x 10 11/16 in. (21.9 x 27.2 cm)
Tom's Paint Box Size, Catalogue 1915.78

The trees also tell a tale, and my Thomson friend suggested several observations. 

The illumination of the tent face and the extreme left edge of the trees can be combined with the orientation of the elongated band of altostratus. The following geometry results with the morning sun on Tom's left shoulder looking at the arch of a swath of stable cloud. The altostratus was likely associated with the anticyclonic companion of an approaching warm conveyor belt. Tom was looking westward. The winds were probably light. It would have been a great day to paint outside with no biting bugs. 

Horace Kephart, 1862-1931

My Thomson friend, also an avid canoe tripper recalled an "excellent source for information on old-style camping in Horace Kephart's book "Camping and Woodcraft". The first book  "Camping and Woodcraft: a Guidebook for those who travel in the Wilderness" was first published in 1906. Tom might have owned a copy! Volumes One and Two were written in 1916 and 1917 and were combined in 1921 as the "Two Volumes in One" Edition. Horace Kephart's writings are certainly relevant to the period of interest concerning Tom Thomson.  The complete work is available free online. Further, my Thomson friend located "Chapter V, Tents for Shifting Camps".  

Horace wrote: "the most suitable material is very closely woven stuff made from Sea Island or Egyptian cotton... the standard grade of 'balloon silk' runs about ... 5 1/2 oz (per square yard) when waterproofed with parafine. This trade name, by the way, is an absurdity: the stuff has no thread of silk in it, and the only ballooning it ever does is when a wind gets under it." Horace had a wonderful sense of humour as well. 

Balloon silk was tightly woven and would shed the rain unless touched from the inside. Thankfully, modern tents have largely eliminated that problem!

As my Thomson friend also noted: 

"Kephart talks a lot about outfitting for groups, but also more individual efforts, and includes contemporary information about everything related to camping and getting along in the woods.  Interesting to read in 2024, and gives us a good idea about how things were more than 100 years ago.  I think there is a lot that can give us some idea of Tom's equipment, food and camping experience..."

 

Thomson took this photograph of his prized "silk" tent and the catch of the day. A stark photograph of a white tent does not tell the story of Tom's tent nearly as well as his painting. The picture shows the ballooning effect of the wind on the very closely woven fabric of the tent. 

Tom had pitched his tent properly for this image with the ridge pole on the inside. Tom did not have the side poles to hold the side walls out but had set guy lines and pegs. 

Artist's Camp, Canoe Lake, Algonquin Park

But first, before Tom could camp in the woods and be away from the bustle of the big city, he had to make a living. The following interview with "Leonard Rossell, Reminiscences of Grip, members of the Group of Seven and Tom Thomson" provides a wonderful background to Tom Thomson.

Grip was a commercial design firm Thomson worked at in Toronto. Tom Thomson is in the front right of the above photo. J. E. H. Macdonald is in the background, at the end of the row. A. H. Robson is likely the man seated on the left side of the image. Tom looks like a man who would rather be elsewhere.. almost anywhere else would be just fine.

This link is to the entire interview with Leonard Rossell but the following quote sums Tom up nicely: 

"At the office we had great arguments on the relative value of tents, fishing tackle, etc.; on anything to do with camping and woodcraft Tom was a master. He could pack his camping equipment, paints, etc. etc. into the smallest compass. He knew all about the best rods and flies for fishing. Indeed he eked out his small supply of cash by acting as guide up in the wilds of Algonquin. That he was an expert canoeist goes without saying. While the mosquitoes were singing outside his silken tent he would be painting some mood of nature from the inside."

Artist's Camp, Canoe Lake, Algonquin Park

This is another one of those panels from the stack of Thomson's paintings retrieved from the Shack.  Lawren Harris and J.E.H. MacDonald had taken on a formidable task in the spring of 1918. In this case, the application of the Estate Stamp on "Artist's Camp, Canoe Lake, Algonquin Park" did not cause much damage to the lower right of the panel. This time, these gentlemen selected the perfect name for one of Tom's paintings. 

Inscription recto: 

• 
  l.r., estate stamp 

Inscription verso: 

• l.l., estate stamp; 
• label, Laing Galleries, Toronto; 
• sketch of deer Thomson Collection @ Art Gallery of Ontario 

Provenance: 

• Estate of artist 
• George Thomson, New Haven, Connecticut and Owen Sound, Ontario 
• Laing Galleries, Toronto 
• Father of J.S.D. Tory, 1951 
• J.S.D. Tory, Toronto 
• Montreal Trust Company, Executor of Estate of J.S.D. 
• Tory Private Collection, 
• Toronto Thomson Collection @ Art Gallery of Ontario

This painting went to Tom's older brother George - certainly as one of George's allotment. Each of Tom's siblings received at least ten paintings. 

The mythology of Thomson has grown around the man in the last century. Roy MacGregor wrote the following on page 172 of  his book "Northern Light":

"The Wattie family has its own lore about Thomson. They joked about how he had, over time, become revered as an expert outdoorsman. 'He was not an expert canoeist,' says Copper. ' He hadn't even seen a canoe until he got to the park.' But Thomson was game and generous, and Wattie took him under his wing..."

Thomson was indeed game and he wanted to learn. That opportunity is available to everyone (as it was detailed at the start of this blog). Thomson's story is similar to the lyrics of "Rocky Mountain High".  John Denver  (1943-1997) had moved to Aspen, Colorado in 1969 and he wrote the truth about his inspiration with his guitarist Mike Taylor. The song was released in September 1972. 

"He was born in the summer of his 27th year

Coming home to a place he'd never been before

He left yesterday behind him, you might say he was born again

You might say he found a key for every door..."

Thomson arrived in Algonquin Park in May of 1912. He was 34 years old with less than five years of serious painting ahead of him. Tom was a solitary painter during the last three years… and he blazed his own trail. You can’t go anywhere new by following the herd.

I am greatly indebted to my Thomson friend for the valuable insights and suggestions included in this post! It was a banner week and there were many things to be learned. The story behind the art can be just as illuminating as the brush strokes.  Thank you!

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: Should you wish to have Creative Scene Investigation applied to one of Thomson's works that I have not yet included in this Blog, please let me know. It may already be completed but needs to be posted. In any event, I will move your request to the top of the list. If you made it this far, thanks for reading! There is a lot of science in this small panel and I wanted to cover most of it...

PSS: Tom Thomson had a close friendship with Tom Wattie, the Park Ranger stationed on North Tea Lake. They first met in 1913 when Thomson paddled north through the Algonquin lake chains. Wattie and his family lived in South River, but owned a small cabin (camp) on an island on Round (Kawawaymog) Lake, at the western edge of the park. In the fall of 1915, Tom Thomson, Tom Wattie and local South River doctor, Dr. Robert McComb, spent several days at the camp. While Wattie and McComb went hunting, Thomson painted, and in a frenzy it would seem. Although several birch board paintings fueled the nighttime campfire, at least 5 remain from that time: Sand Hill, White Birches on Round Lake, The Tent, Dawn on Round Lake, and Chill November (which was also set on Kawawaymog Lake, but painted the following winter in his Toronto studio).

Tom Thomson's Evening Cloud Fall 1915

Thomson was inspired by the weather. Artistic compositions full of varying tones and colours are presented hourly with the changing weather - and the paintings literally come to you! One does not need to travel to the south of France to be energized. I have been blessed with the same situation during the past four years of COVID. Nature and specifically the weather can be everything that you need to find a purpose in life. 

"Evening Cloud" from the fall of 1915 is an exuberant example of Tom at his best. The low horizon characterizes his skyscapes with the clouds as the star attraction. 

Evening Cloud
Alternate titles: Evening Clouds; Storm Cloud; Storm Clouds Fall 1915
Oil on composite wood-pulp board 8 9/16 x 10 9/16 in. (21.7 x 26.8 cm) 
Tom's Paint Box Size, Catalogue Number 1915.76

Tom included all the clues we needed to fully understand the weather that autumn evening. I asked my colleague Johnny Lade to have a look at this painting as if he was making a weather observation. Known to his students as "Johnny Met", he has a lifetime of experience observing the actual weather. Johnny nailed this observation since Thomson painted exactly what he saw.

"This painting looks like the true atmosphere The main cloud mass is a towering cumulus in a dissipating stage. The tops are still in the sunshine maybe at the 20,000 range. The grey bottoms are blocked from the sunshine by the tops. The clouds are moving away from the painter and the bottoms might indicate a passing showers. The dark horizon indicates showers as a cold front moves away leaving a fresher brand of air. The wind behind the front is stirring up the lake and the sun is reflecting off the waves."

Johnny's observation rings true and will be further explained in the following graphics.  

The towering cumulus was front-lit. The sun was on Tom's back and his right shoulder.  The distant shore was in shadow (dark tone) and lacked colour. The sun had set at least at the lowest levels of Tom's vista.

The cumulus congestus cloud was still vigorous but starting to dissipate with the setting sun. The cold front that Johnny mentioned provided the trigger to initiate that convection but a significant portion of the convective available potential energy (CAPE) was still provided by the sun. The bright faces of the towering cumulus turned toward the setting sun lacked the cauliflower texture of a robust, convective bubble. 

Rayleigh scattering removes the shorter wavelengths from the direct beam of the setting sun. The original white light of the sun becomes increasingly orange and then red as it passes through an ever-increasing atmospheric path until the sun sinks below the western horizon. 

The following graphic (made to explain another painting) summarizes the effect of Rayleigh scattering on the colour of the light remaining to illuminate the scene. Increasing amounts of particulates within the planetary boundary level during the day can scatter all but the longest wavelengths from the visible spectrum - only red light remains in some sunsets. Red sunrises are rare and more likely to be yellow or orange. 

Tom observed the dark cumulus congestus cloud base as purple! As Johnny noted, the direct beam from the setting sun was no longer reaching that portion of the cloud. The cloud was optically thick and no light was getting to the cloud base through that towering cumulus. Blue light from Rayleigh scattering could reach the cloud base. Red sunset light forward scattered by large particles (Mie scattering) in the lowest levels of the atmosphere combined with the blue to result in the purple that Tom painted. 

The large convective raindrops that comprise the shower under the towering cumulus were painted distinctly grey! Tom had to mix some burnt or raw umber with his oils to record that colour. Matching that distinct colour had to be a very deliberate act! The larger raindrops can only Mie scatter any incident light in a forward direction. The setting sun only provided minimal red light at that low elevation and an even smaller amount of that could be returned to Tom's eye. Minimal light passed through the optically thick cloud. The colour of the shower had to be darker and lacking in colour. Tom painted what he saw. 

There is another factor to consider when explaining the purples and pinks that Tom observed! Tom was also possibly looking at the eclipse of the atmosphere by the shadow of the earth - the Belt of Venus (associated with the Greek goddess Aphrodite and Roman goddess Venus - not the second planet in the Solar System). The Belt of Venus is not an available option for any back-lit illumination. 

The earth casts a shadow on the lower atmosphere twice a day at your location: the first at sunrise if you gaze toward the west and the other at sunset looking toward the east. The shadow in the sky lasts only about 15 minutes - just long enough to boldly observe and lay the oils on a sketch. This “Belt Of Venus” phenomenon helps to explain the even pinker colours of the towering cumulus on the eastern horizon. 

The following graphic to explain this phenomenon must be greatly distorted.  

• Remember that the atmosphere is actually quite thin similar to the skin of an apple. The troposphere where almost all weather occurs extends only 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is dense and thus the most likely to scatter light creating the visual effects that we enjoy. 
• Also, recall that the sun is far from the earth at about 8.3 light-minutes away. On average, the earth is 150 million kilometers away from the sun.
• The earth is only 12,742 km in diameter. The dimensions of the earth are dwarfed by the distances involved. 

The Belt of Venus (also called Venus's Girdle or the anti-twilight arch) is an atmospheric phenomenon visible shortly before the sun rises or after sunset, during civil twilight (the geometric center of the sun is within 6 degrees below the horizon). The pinkish glow surrounds the observer and extends 10 to 20 degrees above the horizon.

An artist can't chase the fleeting colours of light while painting en plein air. Nature and especially the weather change so fast that one must decide when to lock in the colours and composition and ignore what changes might occur after that. My advice to students was to first paint what was changing the fastest - "lay the oils in and leave them alone - move on". Remember that light moves at 186,000 mi/sec or 3 followed by eight zeroes meters per second. That is fast! Students to tried to chase the light usually ended up painting "mud". Thomson's strength was "to observe, lay it in, and never touch it agin."

The study of light and its interactions with particles in the atmosphere can fill several textbooks. Happily, artists can stay scientifically accurate if they just paint what they see. Tom did just that!

The gravity waves in the altocumulus clouds at the top of the panel indicated that the winds were southerly at that elevated level. The wavelength of those gravity waves can even be used to estimate the wind speed - something I did when I was an operational meteorologist. I do not do that anymore and you do not need to. 

All of the above allows us to place Thomson within the weather patterns of that autumn evening. The cold front was passing Tom's location as the warm sector of the weather system receded to the east. 

Significant wave action but with minimal white caps suggested that the winds were Beaufort Scale Gentle Breeze of 7 to 10 knots producing "large wavelets, crests begin to break, scattered whitecaps". The surface winds had been blowing from right to left (from the south) but with the passage of the cold front, the winds would have started to veer to the west. The shore on which Thomson was standing would have significantly reduced the fetch of the wind over the lake justifying a higher wind speed estimate based solely on the Beaufort scale.

The nondescript distant shoreline location could be anywhere... and probably no one knows.

The oils were smeared along the left and right 
edges of the panel when Tom placed and later
removed the art from his paint box. 

Inscription recto: 

• l.r., estate stamp 

Inscription verso: 

• c., estate stamp; 
• u.c., in pink graphite or pastel, 28; 
• u.l., in graphite, (undistinguishable) / Tom Thomson / p..d / 35OO ; 
• u.l., in graphite, le… (crossed out); 
• u.l., in graphite, RWL (crossed out); 
• u.l., in graphite, …(crossed out); 
• u.l., in graphite, S..nset; 
• u.c., in red pencil, Laidlaw; 
• u.r., in graphite, fall 1915 2?; 
• u.r., in red pencil (circled), 16; 
• l.r., in green graphite or pastel, B or 13; 
• l.r., Gift to R.W.L.L./R.a. Laidlaw; 
• l.r., in green graphite or pastel, B or 13; 
• l.c., in graphite, 14. M. Thomson (crossed out); 
• l.c., in graphite, 8; l.l., in graphite, J & ???t / Studio Bldg / To; 
• u.l., label, in red pencil, Gift to R.W.L. Laidlaw / R.A. Laidlaw; 
• u.r., label, in red pencil, T 45 Thomson Collection @ Art Gallery of Ontario 

Provenance 

• Estate of the artist 
• Elizabeth Thomson Harkness, Annan and Owen Sound 
• W.A. Laidlaw, Toronto 
• R.A. Laidlaw, Toronto, 
• after 1959 R.W.L. Laidlaw, Toronto and King City, 
• by descent Ken and Brenda MacDonald, Winnipeg 
• David Loch, Toronto 
• Private collection, Toronto 
• Thomson Collection @ Art Gallery of Ontario

This is another one of those panels from the stack of Thomson's paintings retrieved from the Shack. In the spring of 1918 Lawren Harris and J.E.H. MacDonald had a virtually impossible task to sort through The application of the Estate Stamp on "Evening Cloud" did not cause much damage to the lower right of the panel. 

This graphic also highlights the wave action lacking in white caps. 

The alternate titles for "Evening Cloud": Evening Clouds; Storm Cloud; Storm Clouds suggested by Harris and MacDonald missed the mark. The cold front had passed and fair weather was on the way overnight. The westerly or northwesterly winds would diminish. The pressure was rising, The following day would be a great day for more pein air painting of the autumn colours. 

This painting went to Thomson’s eldest sister upon his passing. Elizabeth's husband was Thomas “Tom” J. Harkness who was appointed by the Thomson family to look after the affairs of Tom’s estate. T. J. and Elizabeth lived in Annan, Ontario, just east of Owen Sound. From Elizabeth, aka "Mrs. Harkness", the painting went to the Laidlaw family who were avid collectors of Thomson's art (as encouraged by Harris). Eventually, the painting went to the  Art Gallery of Ontario where I first saw it - nose to nose. 

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: Should you wish to have Creative Scene Investigation applied to one of Thomson's works that I have not yet included in this Blog, please let me know. It may already be completed but needs to be posted. In any event, I will move your request to the top of the list. If you made it this far, thanks for reading! There is a lot of science in this small panel and I wanted to cover most of it...

Tom Thomson's Autumn Clouds Fall 1915

There is an element of a detective story in the Creative Scene Investigation (CSI) of each of Thomson's weather observations. The Who, What, When, Where and Why of the story always starts with just the image. That is all we have. The cloud types and wind that Tom painted can only be found in one portion of a weather system. Please let me explain. The story started decades aog...

Autumn Clouds Fall 1915
Oil on wood panel 8 9/16 x 10 9/16 in. (21.8 x 26.9 cm) 
Tom's Paint Box Size, 1915.75  

I was very fortunate to attend a lecture by Roger Weldon in 1981 while working at the Alberta Weather Centre in Edmonton. Weldon's work on storm patterns and specifically deformation zones was illuminating! His words opened a whole new world of scientific inquiry. 

It took a couple of years of fermentation and working with the new satellite data "for the penny to drop". The Eureka moment came on a 1983 night shift at the Atlantic Weather Centre in Bedford Nova Scotia. Every line in the atmosphere was a deformation zone when viewed from the atmospheric frame of reference - something that the new satellite data allowed. Everything made immediate sense when examined while moving with the atmosphere. The earth (a spinning ball with a thin and fragile skin of atmosphere) was not even close to being the perfect frame of reference. "Humans" were not the centre of the universe. 

The current conceptual model of the deformation zone (above) took years of further investigation. Some consistent terminology needed to be invented to differentiate between paired and companion vortices that differentiated between the swirls. Swirls that were across the deformation zone from each other were "paired" and responded in opposite directions to changes in confluent asymptote curvature. The "companion" swirls straddled the inflows to the col along the axis of contraction. They were simply cross-sections through the "3-D smoke ring" generated by the system relative wind. These swirls reacted to the inflow wind speed and deformation zone curvature. The shape of the two divergent confluent asymptotes that comprise the axis of dilatation (deformation zone) also contained information on system motion, thermal advections and stability. Deformation zones are independent of time and space scales and can be stacked vertically to diagnose changing stability due to advections. The deformation zone became my new bestie!

For further background information, consider "A Closer Look at Lines in the Sky" and "The Swirls and Deformation Zone Revisited" among the many times I have written on the subject. Most people are challenged by a frame of reference other than their own experience. I visited that material in "Down to Earth Meteorology" and "A Jet Streak with a Paddle" as well as several other posts. My strategy was to attempt different approaches to the same material until one reached the client. We all see things through different filters and lenses. 

The concept that a cold front was actually a deformation zone received a luke-cold reception (actually frosty) when I got to the Atmospheric Environment Service (AES) Training Branch. I probably did not explain the ideas succinctly (I still stuttered especially when I got nervous).  A warm front is also a deformation zone along with every other edge of moisture you care to scrutinize.  Examining atmospheric processes from the vantage of a moving perspective was not easy in 1985. A representative from the Ontario Weather Centre (OWC) was sent to learn my approaches to satellite imagery but spent the time in the cafeteria. I persisted but it took decades and the effort continues today within these blogs. New computer approaches to data display are making the atmosphere come alive even on your phone.

Tom's "Autumn Clouds" had to be along a cold front. The wind shift that Tom recorded also places him in a very specific location along that deformation zone. The following graphic will explain that better than words. 

The following graphic describes the diagnosis of the cloud types and winds painted by Tom.

The cumulus clouds were triggered by the cold frontal passage. The individual cells leaned forward toward Tom with the strong southerly to southwesterly winds aloft. The surface winds were reduced by friction in the planetary boundary layer (PBL) while those aloft were largely unaffected by the rough terrain and were thus stronger.

The turbulent stratocumulus clouds were paralleling the cyclonic companion winds of the dry conveyor belt. The instability along the cold front provided the necessary conditions for those Langmuir streaks. 

Both the cumulus and stratocumulus clouds locate Tom at the cold front of the weather system but there is more to be discovered in the mid-levels of the atmosphere...

The conveyor belt conceptual model that I tend to use in these blogs is for a mature weather system. Heat and moisture must follow constant energy surfaces on their journey from the source region in the tropics to the poles. Three adiabatic levels are good summaries of this flow. The highest flow (yellow in the graphic below) symbolizes the cirrus level. The orange flow is for mid-level moisture (altostratus and altocumulus) and the red level is reserved for low-level moisture. 

This is a big part of the energy balance of the planet moving heat, moisture and momentum (as well as electricity) around the globe. The high-level cirrus layers are typically confined to the warm side of the jet stream. As the low (vortex) intensifies and the system slows down, the original vortex occludes. This means that the surface wave and fronts (and cirrus) keep moving with the jet stream. The surface wave remains attached to the vortex only by an occlusion or a trowal. The "trowal" is a Canadian invention meaning a "trough of warm air aloft" since the characteristics of the elevated air mass (the occluded front) are often not distinguishable at the surface. 

Tom was painting a weather system that was in the early stage of occlusion. The mid-level cloud following the mid-level adiabatic surface (orange layer in the accompanying graphic) was wrapping westward to the occluding low-pressure area (cold low or vortex). The satellite image on the right side of the graphic shows a fully occluded weather system with bands of moisture wrapping around a cold low. This is a frequent occurrence in the atmosphere including January 13th, 2024 as I write this post (satellite image below).

Often, satellite imagery provides the first clue that a weather system is occluding. The cyclone (vortex) in the upstream cold trough starts to really wind up. The strengthening circulation that occurs at the mid and lower levels in the atmosphere draws the mid-level moisture around the cyclone and out from under the cirrus cloud shield. This mid-level "hang-back" moisture may be upstream from the warm conveyor belt but is still an important part of the storm. This moisture is also frequently referred to as the comma head of the storm. The track of the occluding low is a good place to start when forecasting the swath of heavy precipitation. This is what Thomson saw and painted. Tom observed the layer of altostratus reaching back to the low. 

The following graphic is a close-up of the viewing angles for the leaning cumulus at the surface cold front and the turbulent stratocumulus streaks along the frontal surface. The mid-level altostratus is also depicted forming in the overrunning above the warm frontal surface and being drawn westward along the occlusion and around the vortex. 

Mid-level moisture is witnessed as it climbs the warm frontal surface and is drawn around the intensifying vortex at the red X. Satellite water vapour imagery often displays several layers of cloud at different levels of the atmosphere swirling around the vortex. The above sketch suggests that the altostratus had not yet completed one swirl around the vortex. More vigorous or older vortices can cause that moisture to make several trips around the low. This graphic illustrates the simplest case occlusion. 

These occluding systems gradually move slower as they intensify and typically become a nearly stationary and vertical cutoff cold low while the warm moist air of the warm conveyor belt continues to move away with the jet stream. This is the occlusion process described in just a few words. The cold low will remain stationary producing lots of weather, wind and precipitation until another impulse of atmospheric energy (an atmospheric wave rippling along the jet stream)  approaches to eject it back into the flow. When the upstream pulse of energy gets within "twenty degrees of latitude", the cold low moves back into the jet stream flow. 

The following graphic assembles all of the puzzle pieces into a solution. The occlusion process was just starting and not developed sufficiently to block the setting sun.

This is all old-school meteorology before the rapid advances of numerical weather prediction (NWP). This approach dates from when understanding the atmosphere was an observational science of the real atmosphere through satellite and radar and not the tweaking of NWP simulations and equations.

The clues analyzed within the painting require that Tom was looking northwestly to observe these cloud types which were still illuminated by the late afternoon sun. The surface cold front was crossing his easel while the hang-back altostratus was being drawn westward around the occluding cold low. 

At this point, I reached out to my Thomson friends inquiring if they might know where "Autumn Clouds Fall 1915" was completed. The result came back in minutes… and it was a match.

Tom accurately observed and painted the weather so that a century later, one can deduce where he was and what he saw. We already knew who! The late afternoon colours of the clouds even reveal when. The colours of the terrain and vegetation suggest that the timing of this plein air painting was also quite late in autumn before the snow started to fall. We can even guess why. The weather and wind were unusual and just had to be recorded in oils - an occluding cold low was just to the west.

Discovering this story allows us to almost be there beside Thomson while he painted, experiencing the weather with him. The art can become an experience beyond the simple pleasure of enjoying the brush strokes and pigments. Sharing this with others is a big motivation for these posts. The opportunity to do so would be lost without the knowledge and generous support of my Thomson friends.

Inscription recto: 

• l.l., estate stamp 

Inscription verso: 

• c., estate stamp; 
• c., in red crayon, Laidlaw; 
• u.l., in graphite, 17 (underlined); 
• u.l., in red crayon, L; 
• u.l., in graphite, WCL (circled); 
• u.r., in graphite, Not to be touched / up round stamping / J.MacD. (underlined); 
• u.r. quadrant, in red pencil, 29 (circled); 
• c.r., in red ink, Gift to McMichael, R.A. Laidlaw (underlined); 
• u.r. quadrant, in graphite, No. / 51 Mrs. Harkness; 
• c.l., in green ink, 12 McMichael Canadian Art Collection, Kleinburg (1966.15.25) 

Provenance:

• Estate of the artist;
• Elizabeth Thomson Harkness, Annan and Owen Sound 
• R.A. Laidlaw, Toronto
• McMichael Canadian Art Collection, Kleinburg (1966.15.25). Gift of R.A. Laidlaw, Toronto, 1965

This is another one of those panels from the stack of Thomson's paintings retrieved from the Shack. In the spring of 1918 Lawren Harris and J.E.H. MacDonald had a virtually impossible task to sort through Tom's efforts of the previous three years. Sadly large chunks of paint flaked off the panel where the estate stamp was applied. 

This painting went to Thomson’s eldest sister upon his passing. Elizabeth's husband was Thomas “Tom” J. Harkness who was appointed by the Thomson family to look after the affairs of Tom’s estate. T. J. and Elizabeth lived in Annan, Ontario, just east of Owen Sound. From Elizabeth, aka "Mrs. Harkness", the painting went to Robert .A. Laidlaw and then to the McMichael in 1965.   

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: Should you wish to have Creative Scene Investigation applied to one of Thomson's works that I have not yet included in this Blog, please let me know. It may already be completed but needs to be posted. In any event, I will move your request to the top of the list. If you made it this far, thanks for reading! There is a lot of science in this small panel and I wanted to cover most of it...

PSSS: It has taken time and effort since the Training Branch in 1985 but the unifying theories of lines and swirls observed from an atmospheric frame of reference have gained wide acceptance elsewhere through the support of COMET, NOMEK and EUMETSAT. I met some wonderful friends on those trips. These posts hopefully will spread the ideas to everyone so that like Tom Thomson, they might appreciate the beauty of the weather and the science that explains it. The conceptual models and meteorology are also blogged in "The Art and Science of Phil the Forecaster".

Tom Thomson's Ragged Lake 1915

 

The low horizon classifies this as another of Thomson's weather studies. There is more going on in the sky than he probably imagined.

Ragged Lake was a short paddle downstream from Canoe Lake. The canoe made Algonquin accessible long before the Frank MacDougall Parkway. Frank MacDougall would have been just 19 years old in 1915 when Tom painted this skyscape. Frank would be the Superintendent of Algonquin Park between 1931 and 1941. Highway 60 was started around 1937 during his tenure making Algonquin much more accessible. 

The outline of the waterway is very convoluted and torn so the name of the lake is not a mystery. Tom was certainly painting from shore but which location was a riddle to me. My Thomson friend provided a very plausible suggestion located at the gold star in the above graphic. I certainly do not recognize the trees or the terrain in Tom's painting and it does not matter anyway. This composition is all about the clouds and in that matter, I can help!

Ragged Lake
Alternate titles: Northern Lake; Ragged Creek Fall 1915
Oil on wood panel 8 3/8 x 10 5/16 in. (21.2 x 26.2 cm) 
Tom's Paint Box Size, Catalogue 1915.74

The clouds that Tom observed were stratocumulus. These humble clouds are vastly underappreciated as they can reveal much about the atmosphere and the weather - past, present and future. Please read on. 

Clouds like stratocumulus found in the planetary boundary level exchange energy with the terrain. In fact, the planetary boundary layer is defined as the zone in which the atmosphere exchanges heat, moisture and momentum with the land. The Tephigram is an essential tool to fully understand and appreciate these clouds. Some of the details of the tephigram may be found in "What Goes Up ...".  Tephigrams along with satellite and radar data were my best friends when I was trying to understand and predict the weather. I always started with observations of the real atmosphere.

Examining clouds and weather using the Tephigram can go both ways. When I am outside (perhaps painting), I examine the base, sides and tops of the clouds and determine the LCL, LFC, CAPE, NBL  and Energy Balanced Level. Don't worry, these abbreviations will be described and labelled on the following summary graphic which is an example of an unstable Environmental Temperature Profile (ETP).

• The LCL reveals how much moisture is in the air mass. The closer the cloud base is to the ground, the higher the relative humidity of the air mass. 
• The characteristics of the cloud base reveal whether it was the sun and daytime heating or turbulent mixing which raised the parcels from the surface to the lifted condensation level. A uniform and level cloud base indicates that the sun did the lifting and the air parcels rose like hot air balloons along the dry adiabats.  A ragged cloud base indicates that the wind and turbulent mixing over a rough terrain raised the air parcels to saturation. 
• If the lower levels of the cloud rise vertically (examine the lower cloud edges), the LCL is also the level of free convection, LFC. If the lower cloud edges are rough, ragged and not vertical, the LFC is to be found higher in the atmosphere - or not at all in a stable environment. Any cloud edges above the LFC are oriented more vertically and shaped like cauliflowers as the thermals rise convectively. 
• The Level of Neutral Buoyancy, NBL is where the cloud tops start to flatten out especially on the outer edges of the thermal.
• If the air parcels accumulate significant Convective Available Potential Energy, CAPE during their ascent, some thermals will continue to climb above the NBL until that momentum is all spent in reaching the Energy Balance Level. These energetic "hot air balloons" are typically located in the central updrafts of the cloud as opposed to the edges. 

These quantities can also be identified from the tephigram perspective. Once analyzed, I typically drew pictures of the expected cloud on the edge of the Tephigram. The Tephigram was also a vital tool to predict the maximum temperature given the expected amount of solar radiation. In this way, one can anticipate the type and structure of cloud that must form, given the physics. Indeed, anticipation is just another word for forecasting.

So let's take a look at Tom's stratocumulus. 

The stratocumulus was shaped by a wind blowing from left to right. The clouds were front-lit with that light originating more from the right. Tom had to be looking northeast with the late afternoon sun on his right shoulder. There were subtle shadows from shoreline trees pointing away and toward the northeast consistent with the afternoon lighting of the scene. The cool, northerly breeze would have been keeping the biting bugs down. Life was good!

The following is the same interpretation as that above but with a focus on the tephigram and an estimate of the Environmental Temperature Profile - which was marginally conditionally unstable. 

Tom's weather observation is a good opportunity to distinguish between stratocumulus and cumulus clouds.

Cumulus clouds are the other cloud type that characterize an unstable profile in the planetary boundary layer. Cumulus clouds tend to be whiter and brighter than stratocumulus. Fueled by at least one thermal with significant CAPE, cumuli are composed of smaller and younger cloud droplets which Mie scatter the incident light in all directions. Stratocumulus are greyer and darker being composed of larger and older cloud droplets. Mie scattering from large cloud droplets tends to scatter incident light in a forward direction away from the source.

If the air mass is especially unstable, cumulus clouds can evolve into towering cumulus (upper left of the graphic below) and even cumulonimbus (right side of the graphic). One can gauge the amount of instability and CAPE by monitoring the top of the cumulus. Think of the updraft generating the convective, cauliflower top as a vigorous smoke ring with a vortex rotating and coiling around it. 

Try to visualize the three-dimensional hot air balloon thermals that comprise the various types and intensities of cumulus clouds. 

Clearly, the clouds that Tom observed were stratocumulus. Tom's painting does not reveal how these clouds were arranged over the landscape. The absence of higher clouds indicates that the weather was not associated with a warm conveyor belt. The northerly winds suggest that the stratocumulus was aligned in cloud streets paralleling that direction. Langmuir streaks are explained in the following graphic. 

If we assemble all of these puzzle pieces, we can picture where Tom was painting in the context of the weather. The following graphic is what we see. 

I asked a colleague to have a look at this painting. My meteorological friend John Lade was nicknamed "Johnny Met" by his very fortunate students. Even without a tephigram or laser ceilometer, Johnny offered the following:

"Stratocumulus. To me, it looks like it is late in the day with the setting sun making the clouds turn red. Daytime heating has ended and the afternoon cumulus are spreading out.  A tephi sounding would show the base of the clouds but I estimate the ceiling at around 3500 feet." 

A second diagnosis is always a good thing. 

My memories of tephigram analysis and clouds are all wonderful. The clouds would appear from those numbers and lines and I would sketch them on the tephigram margins with annotations of wind shear. "Tephigram Analysis" was listed as just one of the many duties that had to be completed twice a day for the radiosonde sites affecting the forecast area. I never viewed it as a chore but rather as an opportunity to be a creative detective solving the mysteries of the coming weather.

Inscription recto: 

• l.l., estate stamp 

Inscription verso: 

• c., estate stamp; 
• in graphite, T.T. A Northern Lake / NOT FOR SALE; 
• in graphite, 79 M. Thomson; 
• RAL; in red, 30 (circled) 
• Art Gallery of Hamilton (63.112.U) 

Provenance:

• Estate of the artist 
• Margaret Thomson Tweedale, Toronto 
• W. C. Laidlaw, Toronto? 
• R.A. Laidlaw, Toronto 
• Mrs. G.Y. Douglas 
• Art Gallery of Hamilton (63.112.U). Gift of Mrs. G.Y. Douglas, 1963

This is another one of those panels from the stack of Thomson's paintings retrieved from the Shack just south of the Studio Building at 25 Severn Street in downtown Toronto at the edge of the Rosedale Ravine. In the spring of 1918 Lawren Harris and J.E.H. MacDonald had a mountainous and virtually impossible task to sort through Tom's efforts of the previous three years. This painting went to Tom's youngest sister Margaret Thomson Tweedale (1884-1979). Margaret was the ninth of ten children born to John and Margaret Thomson. She was a teacher for 15 years before marrying William Tweedale. 

Margaret remained fiercely protective of her brother’s reputation. The creative siblings were brought even closer after his death. The oldest son George (about 1868 - 1965) started spring and fall painting expeditions which Margaret joined in on. She preferred to paint landscapes and "she created a small body of charming works". 

Margaret sold this painting to Walter Cameron Laidlaw (1875-1962), the older brother of Robert Alexander Laidlaw (1886-1976). Recall that Lawren Harris advised the Laidlaws to purchase Tom's work whenever they had the opportunity. Apparently, Margaret gave them that chance. Eventually, the painting went to the Art Gallery of Hamilton for all to enjoy. 

The Thomson Family Children 1887

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: Should you wish to have Creative Scene Investigation applied to one of Thomson's works that I have not yet included in this Blog, please let me know. It may already be completed but needs to be posted. In any event, I will move your request to the top of the list. If you made it this far, thanks for reading! There is a lot of science in this small panel and I wanted to cover most of it...