The low horizon classifies this as another of Thomson's weather studies. There is more going on in the sky than he probably imagined.
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!
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| 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). 
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:
Inscription verso:
Provenance:
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.
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... |
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