May is prime for thunderstorms in Algonquin Park - especially the supercell type. Tom’s motivation to “record” this particular observation was indeed an approaching thunderstorm. The horizon is at the very bottom of this painting making it yet another skyscape. Tom was a weatherman.
This is a thunderstorm but it would not be obvious to anyone but a meteorologist and to Tom, who was evidently there at the time. Tom could paint the cloud and the wind and the rain but how do you paint the sound? This could be any type of thunderstorm – a pulse, a multicell or even a supercell. Tom only included the approaching lowest level of the convective cell but that is enough. The conclusive components of this painting are the shaft of heavy rain producing the resultant outflow, gust front and the shelf cloud.