A rain-storm being gentle?

Question

From Where I Lived, and What I Lived For by Henry David Thoreau:

This small lake was of most value as a neighbor in the intervals of a gentle rain-storm in August, when, both air and water being perfectly still, but the sky overcast, mid-afternoon had all the serenity of evening, and the wood thrush sang around, and was heard from shore to shore.

A gentle rain storm seems odd to me, isn't it to be at least at some degree of furious to be qualified as a storm? How can gentle be the adjective of a storm?

Answer 1

A gentle rain storm can happen and it depends on the geography of the area and atmospheric conditions. Thoreau is referring more to the downpour of water than the wind and thunder that can accompany storms.

The type of rain Thoreau is writing about also occurs in more southern climates on a regular basis during the summer months when there can be a sudden downpour for a few minutes to release moisture from the air on a daily basis. This type of rain also occurs in the Boston area (Walden) during hot summers and are caused by nimbus clouds. It is usually referred to simply as a downpour as distinct from rain or raining.

Thunderstorms with their great winds are caused by cumulonumbus clouds and require flat terrain to reach their full potential, for example in the Midwest of the US. Because of rolling terrain, cumulonimbus clouds form less regularly in the northeastern US.