Why Are Sunrises And Sunsets So Colorful Before A Tropical System?

Even when I was a small child, and we had the occasional tropical storm approaching, Back in the Delaware Valley, we really didn’t get the storms directly, but we would get affected by the remnants every so often. I remember the sky being so vivid. Sunrises and especially sunsets were always so colorful. I had deduced that it was due to the storm, but never did know why then.

Of course, now I do.

When the sun is setting or rising, it must pass through more of the atmosphere. That scatters and attenuates some of the blue and violet light since it has to pass through more of the atmosphere with the gases in it scattering them more. It’s the same reason the sky is blue during the day. Since blue light is the most scattered, it makes the entire sky look blue.

This leaves the reds and oranges as the dominant light wavelengths to be reflected from the clouds. They tend to be high clouds before storms and well above the dust and stuff in the lower atmosphere, which block more of that light. If the clouds are too low, the bigger particles of dust and stuff block much more of the longer wavelengths of the sunlight, so you don’t really get the color.

I am by no means an expert, but this is the best explanation I could come up with.