Sparrows were feeding in a freezing drizzle
That while you watched turned into pieces of snow
Riding a gradient invisible
From silver aslant to random, white, and slow.

There came a moment that you couldn't tell.
And then they clearly flew instead of fell.

Howard Nemerov

http://www.poemhunter.com/poem/because-you-asked-about-the-line-between-prose-and-poetry/