#2982 "Singleton Sunset on the Ides of October"

#2982 "Singleton Sunset on the Ides of October"
16 x 20 oils on canvas
Started 9 am on Saturday, November 1st, 2025

The sunset colours were striking. One of the challenges would be to do those hues justice on canvas. The other trick would be to explain what the clouds were saying. Both the weather and the colours begged to be accurately depicted. 

The surface winds were light northerly in contrast to the southwesterly winds at the level of the altocumulus clouds. I watched the cloud masses drift toward the northeast, perpendicular to the leading edge. The virga precipitating from that deck of altocumulus clouds appeared to be heading northeast as well, but faster than the cloud! Can the wind below the cloud deck actually be faster than that moving the cloud? Strange! Meanwhile, the ice crystals wafting down from the cirrocumulus appeared to be drifting toward the south. How can we make any sense of this? I can explain.

I watched this sunset and can categorically confirm that the surface winds were light northerly. Singleton was within the cool northerly outflow of the ridge of high pressure on the cold side of an approaching warm front. 

Both layers of clouds were drifting toward me, propelled by southwesterly winds. The drift of the cloud masses toward the northeast confirms that a warm conveyor belt was approaching Singleton Lake. This was consistent with Singleton still being within the cold air. 

The following satellite images and the surface map summarize the meteorological situation. The water vapour imagery indicated that Singleton was under the anticyclonic companion of the warm conveyor belt.  This information is crucial to understanding the clouds.  That sunset sky was full of illusions. 

For those of you who are interested to learn a bit more meteorology, the following graphics will guide your journey, starting with a description of the Warm Conveyor Belt Conceptual Model. The explanations of the conceptual models can be skipped if you wish to jump to the final graphic that details the reason behind the drift of the virga and the observed winds. 

The next step is to employ your Coriolis Hand to decipher the Deformation Zone Conceptual Model. The deformation zone is a divergent flow stretching clouds outward from the col that marks the centre of the contrasting circulations. My favourite conceptual model!

With this information, you can deduce the probable weather by knowing which companion of the Warm Conveyor Belt is overhead. This information will not be on any exam, so no worries!

Now that you are familiar with the concepts, the following graphic summarizes all of the information. 

Now, back to the specific meteorology displayed in the October sunset sky and the painting. Remember that the clouds are always right. We just need to be careful how they are interpreted. 

All of the evidence confirms that Singleton was under the anticyclonic companion of the warm conveyor belt. That area, as described in more detail in the above graphic, is less likely to receive significant precipitation. Also note that the cirocumulus are organized into gravity waves perpendicular to the divergent flow in the atmospheric frame of reference. This could all be deduced without any of the satellite images, just by watching the drift of the cloud masses and individual cloud elements. Art and science actually do make sense. 

The virga illusions result from our non-inertial, rotating frame of reference. The clouds and virga are shaped by the relative winds solely within the atmospheric frame of reference.

How does one look at the relative winds and motions in the atmospheric frame of reference when we are stuck, spinning on the Earth? The average wind guiding a weather system will be in the same direction as the jet stream, only slower. Any motions perpendicular to the jet stream will certainly be the result of winds within the atmospheric frame of reference. These lateral motions will always be the result of a deformation zone. In this sunset, the altocumulus elements producing the virga had a pronounced motion to the left along the anticyclonic confluent asymptote of the deformation zone. 

Situational awareness is also a good place to start. For example, large Singleton storms typically form over the Gulf of Mexico and emerge from the southwest. Alberta Clippers approach from the west or northwest. Practice and ongoing weather watching will teach you everything you need to know?

Finally, here is the simpler, take-home message that anyone can apply. You just need to watch the clouds.

All lines are deformation zones. Deformation zones are typically perpendicular to the average wind. If the cloud along the deformation zone edge is shearing to the left as it approaches, the anticyclonic companion is approaching you. Cloud shearing to the right means that the cyclonic companion and more weather is on the way.  

The water level was probably as low as it would get. Autumn rains were due to arrive with synoptic-like weather systems similar to the one producing this sunset. The three rocky shoals, which are typically totally submerged, were still well-deserved islands. The swimming bear only surfaces in extreme drought. This was the first time in twenty years that we had seen that rock. We had witnessed numerous real swimming bears over the years, but not this boulder version. Every time we glance at the drought-stricken lake and that characteristic rock, we think it is a swimming bear. 

In a drought situation, any mention of precipitation will get everyone's attention. A meteorologist has to be very careful in using those terms. I recalled that we did not get much rain, if anything, from this system. That would be consistent with the anticyclonic companion of the warm conveyor belt passing overhead. Now you know why...

The sunset beaver was typically punctual, and I included my friend in this painting exactly the way it appeared. There are normally two sunset beavers that paddle at sunset to our shoreline to harvest trees. It is nature. I do not interfere.   

For this and much more art, click on Pixels or go straight to the Collections. Here is the new Wet Paint 2024 Collection. 

Warmest regards, and keep your paddle in the water,

Phil Chadwick