Sunday, July 18, 2010

Fair Weather Fun

It is a challenge to paint convective cloud. No sooner have you blocked in the cloud structure and colour, but the cloud changes both in shape and colour. Typically the convection is taller and the bases are darker. The taller clouds places some neighbouring clouds in shadow and these take on a grey colour with a tint of burnt sienna. I have a few of these in this painting.

A knowledge of the meteorology of the situation does indeed help but it is not the solution. The fix is to practice what I preach and that is to leave things "unfinished". Get the first attempt right and leave it alone. That is what I did with this bit of summer-time fun. The cumulus continued to develop and by the time I was finished, the scene was overcast cumulus. The little ridge was passing through Brockville so more weather was on the way!

The sailboats came by just at the right time. I wanted to practice what I preach and this time, there was no delicate touch-ups! It is becoming easier to ignore the finagley details as my older eyes don't see it as clearer as they used to.

Saturday, July 17, 2010

Winter Sunrise

A brilliant sunrise over Ogdensburg, New York -  There was a lot of science in this scene. I hope there was a lot of art as well.

The reflection of the sunrise is most brilliant where the water is smooth and more mirror-like. For sun glint, a rippled surface at a given distance, is less bright as the amount of surface area oriented to reflect the direct sunlight to the eye is certainly less than that of a mirror at the same distance. The amount of sun glint decreases as one looks more directly down on the ripples as the surfaces of the small waves are less likely to be oriented to produce direct reflection of the sunlight to the eye. The best and brightest sun glint reflections occur when the viewing angle is less than 15 degrees to the surface of the water.

The amount of reflected light also decreases as the viewing angle increases so that one is looking more directly into the water. At these angles, refraction of the light into the water dominates reflection. Thus the small amount of reflected light at these angles is light from the sky thus making the ripples more blue. Most light gets refracted into the water and thus the overall appearance of the water is darker.

Sunday, July 11, 2010

"July CU and CI"

Fair weather cumulus (CU) developed early Sunday afternoon. There was more cumulus over the American shore with a minimum over the St Lawrence River. It was apparently holy cumulus - appropriate for a Sunday. A few of the cumulus towered rapidly upward with the crazy wind shear and then was quickly torn apart. The towering cumulus tops sheared up river with the outflow from a high pressure area to the north.

There was a backdrop of cirrostratus (CS) far to the south. In addition there were a few tentacles of fair weather cirrus (CI) in the upper right of the image. The low pressure area far to the south was never a threat for rain along the St Lawrence River.

Monday, July 5, 2010

Tom Thomson - Artist and Weatherman

Thoreau MacDonald (J.E.H. MacDonald's son) wrote a perfect foreword to Ottelyn Addison's book... ``Tom Thomson : The Algonquin Years``

“Thomson’s work would be a fine study for some competent critic, but anyone attempting it should be familiar, not only with every phase of his work, but with the country too. He must know the trees, rocks, lakes, rivers, weather; to have them in his bones ..."

I do not profess to be an art critic or curator but I am fully qualified to discuss the meteorology in Tom`s art. I do hope that you enjoy the discussions in this new web page and that it encourages reflection and positive debate.  In some cases, there are multiple plausible solutions and I attempt to give each a fair presentation. I always try to conclude with the most likely interpretation. Of course, I am making this all up but it is based on some pretty sound science. I wasn't there painting with Tom at the moment of the sketch creation but Tom was a truthful and gifted observer of the natural world. Through CSI (Creative Scene Investigation), I can return to the scene of the time... 
I have been doing presentations based on this material since the early 1990's. I feel it is important as well as interesting to put Tom 's art into context. There are not many of his works that I have yet to apply CSI to.

Sunday, July 4, 2010

"Rocking" - Something a lot different than usual...

It was about to rain but I wanted to play with a panel that I had been using to scrape off my palette knife. I wanted to use the random colours and texture of the scrapings on the panel within the painting of the granite rock on the south shore of Jim Day Rapids. I had the paint and the time and plus there are no rules in the art world... It sprinkled a few drops before I finished but not enough to affect real oil paint.

This can be hung either way - it was meant to be a fun reflection piece.

Saturday, July 3, 2010

Every Cloud Has A Green Lining

I made time to paint. The cold frontal convection was setting up and I thought that it would be fun to try to capture the moment under the shelter of the balcony. This was a thunderstorm although I could not hear the thunder until after it passed. The cell turned right as it crossed the St. Lawrence which is a clue that it was a supercell. It changed so quickly that I just blocked in the colours and shapes. An area of dark heavy rain was followed by a whiter swath of heavier rain and I believe some hail. The updraft was definitely tilted to the northwest. The outflow winds stirred up the waves which were then pounded down by the heavy precipitation. The cloud elements really were that dark.

The cloud has a green lining because the canvas was tinted a cool green but also because the rain is much needed for the ecosystem of the St. Lawrence river valley and the low water levels of the summer of 2010. The cloud also blocks a fair bit of the harmful UV radiation. In fact I much prefer a cloudy day when I am en plein air. There was no way I could have painted this cell from the field.


The process of transformation happens every day. Morning cloud morphs into something new due to daytime heating and the wind. In this case, overcast stratocumulus transforms into cumulus and cumulus fractus with the strong daytime heating commensurate with the sun of early summer. Warm, calm conditions exist under the rising thermals of the cumulus while cool downdrafts mark the compensating descending air that balances the updrafts. What goes up must come down.

The stratocumulus transformed to cumulus faster over the land than it did over the water. Streets of cumulus aligned along the southwesterly winds and funneled down the St. Lawrence River. The cloud patterns changed quickly and it was challenging to keep up with the composition. With time there was more blue sky between the clouds that were transforming from the horizontal to the vertical.