Friday, May 10, 2013

Conveyor Waves

It was a chilly morning to paint. A cold easterly wind of dry air was being drawn into the low pressure centre approaching from the southwest. Meteorologists call this the cold conveyor belt inflow part of the storm. If this flow actually produces an easterly wind at the surface, one knows that the lift and probably the precipitation in the real atmosphere will be enhanced. The combination of the earth frame easterly winds and the motion of the low toward the east (earth-frame again) increase the atmosphere relative collision of air mass flows which produce enhanced vertical lift and thus precipitation.

These gravity waves were at the top of the planetary boundary layer adjacent to the earth. After a night of ground layer cooling the top of this layer was relatively warm and thus pretty stable. Any wind blowing within the boundary layer causes the stable layer to "wave" just like the surface of a lake. These gravity wave clouds are very interesting but with continued daytime heating they quickly disappeared just as I was painting the water surfaces. One of my plein air strategies is to paint the transient subject matter first and leave the content that isn't going to go anywhere until last.
A lone turkey vulture soared the skies while a wild turkey picked bugs in the lawn. The birds, bugs and bull frogs played the sounds of spring. The tree swallows were busy picking off bugs within my reach. A Canada goose sat on the marble point apparently oblivious to my presence.

It occurred to me that the best painters might not know where they are going until they get there and even then they aren't sure... who cares? History will decide if of course history cares...

I actively tried to keep my colours clean with minimal secondary strokes. The joys of plein air painting include picking subjects that interest only you and recording them solely for yourself. The weather does control the plein air painter and I needed to get this completed before the rain heralded by the cold conveyor belt arrived - no problem... it started to rain at 2:30 om local.

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