Tom’s motivation to “record” this particular observation – colours of the hills and the cloud structure. I suspect he was also attracted by the rapid motions of the cirrus clouds with the jet stream and the dramatic dissipation of the cumulus in the warmer air south of the jet.
Given the title one might think that the burnt trees were what attracted Tom’s attention and that the low horizon was just a by-product of that composition. The following meteorological discussion will reveal that it was probably the motions demonstrated by the clouds that drew Tom to this scene. – so to speak.
Sunset colours in the sky confirm that this sketch was a sunset painting and that it was appropriately named. The backlit forest and trees are dark so that the sun had already set although it still illuminated the sky. The brighter part of the sky was on the left side of the panel so that the setting sun was isolated there and Tom must have been looking westerly. One can fine tune this direction by adjusting the location of the sunset to the season - more southwest in the winter and more northwest in the summer.
There is snow on the ground with no leaves on the burnt trees (humour intended), so this is certainly a spring “record” from 1915. There is abundant cirrus and stratocumulus in this cloud mix. These cloud types are consistent with the large scale dynamic lift associated with the distant approach of a low pressure area.