The speaker is describing the weather and linking it to his mood’it tore the elm tops down for spite’ spite is a desire to hurt, annoy, or offend someone.I think he’s in this mood as he might have to kill porphyria but he doesn’t want to as he loves her so much.

in sonnet 29 the speaker seems to thinking wildly as said ‘my thoughts do twine and bud’ she’s using nature here to describe her thinking.