Tom Thomson's “Dawn on Round Lake" tells a story...

Creative Scene Investigation "Dawn on Round Lake"

Thomson painted the wood panel in November 1915 on a small lake just west of his favourite place, Algonquin Park. "Dawn on Round Lake" was one of four oil paintings completed that day while on a hunting trip. Tom was staying at Island Camp with park ranger and friend Tom Wattie (from South River) and Dr. Robert  McComb. Apparently, "Dawn on Round Lake" was painted at Mud Bay on what is now called Kawawaymog Lake.

Tom gifted this particular painting to Dr. McComb. The painting remained in that family for 94 years and then was sold at auction in Calgary to Albertan Tom Budd for $350,000 on April 19, 2009. The painting was expected to fetch $600K but only Tom Budd raised his hand. Mr. Budd expects to donate the painting someday.

Kawawaymog Lake. Some islands in the middle were probably
the location of the "Island Camp"

Dawn on Round Lake [Kawawaymog Lake]
November 1915 Oil on wood 8 1/4 x 10 1/2 in
Tom Thomson's Sketch Box size

First, let’s start with what we know about the work. The title gives the first important piece of information: it was dawn. We can deduce from the painting’s yellow tamaracks that it was also the fall of the year – actually November because the deer rut and hunting season were on. Rifle season for deer typically starts on the first Monday in November. 

Since Thomson shows no sun glint on the water, the sun was at his back. As a plein air painter, Tom would normally paint with the sun to his back anyway. Painting while staring into the sun is difficult at best and at worst, dangerous for your eyes. This typical situation is confirmed by the bright fall colours of the subject matter. The shadowed side of a backlit subject would be in shade and not nerarly so colourful.  So we know through indirect logic that Tom was facing westward. 

The painting has large cloud elements, at least in the foreground. Look at how bright and white the cloud in the left foreground is – that front-lit cloud also confirms the lighting from behind Tom. As a general rule of thumb, a backlit cloud is dark in the middle while a front-lit cloud is white in the middle. 

The vertical cloud elements at the top of the panel are altocumulus floccus which indicates an unstable but dry air mass over the region. The surface temperatures were sure to climb with continued daytime heating. Such an air mass is typically unstable on the outer edge of an approaching low pressure area.

The layered clouds in the distance coming up from the horizon imply a completely different type of air mass — stable with layered moisture — consistent with a low pressure area and gentle lift in the atmosphere. This is the warm conveyor belt of the approaching weather system. The layered cloud is the cirrostratus on the leading edge, lowering to altostratus in the distance. There was no sign of nimbostratus yet so the precipitation was still several hours away. The linear nature of each layer of cloud is the result of the deformation zone. 

The multiple deformation zones that encircle the cloud are characteristic of the leading edge of the warm conveyor belt in the conveyor belt conceptual model of mid-latitude dynamic systems. The deformation zones occur at ever lower levels in the atmosphere until the warm air reaches the surface — the lowest deformation zone is actually the warm front. 

The deformation zone process is very three-dimensional and occurs throughout the atmosphere but is only made visible by the quasi-horizontal layers of the cloud where those layers of moisture intersect with the flow. Perhaps the accompanying graphic might assist with these concepts.

The anticyclonic companion (see The Relativity of the Companion Flows in the Warm Conveyor Belt for more explanation) of the warm conveyor belt was directed toward Round Lake. This is supported by the more stratiform nature of the cloud with the approaching storm. The overhead floccus that certainly attracted Tom's attention would have also been lifted by the "cyclonic swirl" that is an essential part of the deformation zone conceptual model. 

Clearly, there were two contrasting air masses painted here. Tom was in the dry, unstable air mass with chilly morning temperatures. A cloudier, warmer, and probably precipitating air mass was on the way. Note how the deformation zones show no sign of curling/curving so that the warm air mass that they encircle extends far to the right and to the left. This was a large storm. There is no way that the approaching system was going to miss Tom.

The CSI solution is that Tom was looking westerly at a very large approaching low pressure area. The wind, if any was from the east and Tom’s back. This easterly cold conveyor belt wind, however, had not yet been felt at the surface as the air mass still had a radiation inversion set up after a long autumn night of cooling. All of these weather clues were clearly hidden in the bold brushwork of Tom Thomson just waiting to be discovered.

Warmest regards and keep your paddle in the water,

Phil the Forecaster Chadwick

PS: For the Blog Version of my Tom Thomson catalogue raisonné, Google Search Naturally Curious "Tom Thomson Was A Weatherman - Summary As of Now" or follow this link “http://philtheforecaster.blogspot.com/2022/10/tom-thomson-was-weatherman-summary-as.html”