Choose instrumental sounds to represent wind, rain and thunder. Vary the speed of the wind, the texture of the rain - by having different instruments playing - and the loudness of the thunder. How do we control the variables and which sounds best? Use the same starting point, but add the "eye of the storm" by creating a section filled with fearful expectation, through the use of near-silence and understated power. Make a graphic score to show how the musical elements interact.
Debussy's piano portrait of an Atlantic hurricane, Ce qu'a vu le vent d'ouest, uses all the resources of the instrument. Listen to it, and use piano or keyboard to compose a piece in which, like Debussy's, melody itself disappears into the turmoil of evocative sound.
Listen to the Storm interlude from Britten's Peter Grimes. Investigate how the opening theme recurs as a fugue and as a set of variations, how the brass "groundswell" imitates itself at the interval of a minor ninth, and how the triplet passage ominously explores bitonality, visiting D natural and E flat at the same time. Use some of these ideas as a stimulus for a composition.