Rainbows In the Morning

Vero Beach Public Library
No LL

We had several brief but intense rain showers this morning. I got caught by one of them while walking to the library. Now I'm sitting here in the library in wet clothes and freezing because the air conditioner is set so low. At least the hot laptop in my lap feels good.

Anyhow, I wanted to comment on the three spectacular rainbows we saw this morning. I realized that we are accustomed to seeing rainbows much more often in the evening than in the morning. Why is that? For that matter, why do we see spectacular red skies more in the evening than in the morning?

During the years that we lived in Sweden at 59 degrees north, we got to see lots of beautiful rainbows, including double and triple rainbows. You see, near the arctic circle, the sun spends much more time near the horizon than it does at the zenith. Low sun angles and rain create rainbows.

Once, on the Neuse River near New Bern, NC, we saw a rainbow at noon when the sun was at the zenith. That is even more unusual. I recall that the rain bow had a strange squashed shape that puzzled me until I realized that it was precisely because the sun was so high.

My non-scientific guess is that during the day water evaporates from land and sea and at night it condenses. Therefore, there is more water in the air in the late evening than in the early morning. The same phenomenon would explain why thunderstorms happen more often in the evening than the morning.

What about the old proverb, "Red sky in the morning sailor's take warning. Red sky at night, sailor's delight?" It dates back to the Old Testament of the Bible. I make no sense of that and I fail to see that it predicts weather. Various web sites, here and here, attempt to explain it technically, but I think it's mostly bunk. Let me know if you disagree.