It was a chilly morning and heat was leaving my pool at 6 am. The northwest breeze was light but had a cool bite to it. The overnight low temperature was just plus 2 Celsius again. Arctic sea smoke was leaving the lake and taking a lot of heat energy from where I swim with it. The large area of heavy rain had moved east of Singleton and we unfortunately did not get a drop of it.
Sea smoke is also called frost smoke or steam fog. I also saw some steam devils. These weak whirlwinds draw vapour inward into the vortex. These vortices were all cyclonic as far as I could tell which was consistent with my Coriolis hand approach to operational meteorology. The fog formed when the light overnight breeze of cold air mixed with the shallow layer of saturated warm air immediately above the warmer water. The warm air is cooled lower than the dew point and can no longer hold as much water vapour. The condensation of the vapour releases heat energy which helps to fuel the upward convection along with the heating from the relative warm water surface below.
Cold air advection with those northerly winds also created vortices in the top of the stratus. Friction adjacent to the land will slow the surface wind but aloft the wind is unchanged. The resulting wind shear creates curls tumbling along that boundary like a pencil rolling along a desk. The swirls I painted in the top of the stratus reveal that wind shear. These wind shears are typically invisible but they are always present.
I had started my season of swimming as I normally do on May 15th. The water was warming up nicely every day. This last day of May was an exception. There was even some frost on the roof. For this and much more art, click on Pixels. Thank you.
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