Folk wisdom says

Red sky over the Duchy says I'll have an opportunity to catch up on my studio work today.

Red sky at morning, sailors take warning;
Red sky at night, sailors' delight.

Dawn this morning featured a lovely rose-colored sky. Since I trust the ancient couplet, above, as much as (or more than) I trust the Weather Channel, I’ll be teaching in the studio tonight.

How old is that couplet? It’s quoted in Matthew 16:2-3, making it at least two thousand years old:

[Jesus] answered them, “When it is evening, you say, ‘It will be fair weather, for the sky is red.’ And in the morning, ‘It will be stormy today, for the sky is red and threatening.’ You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times.

For those who don't read sky signs and don't trust their arthritis, there is NOAA's weather page, with its hourly graphs. They include sky cover, which makes them the plein air painter's best tool for predicting sunsets.

Joseph Mallord William Turner had a great interest in painting atmospherics. Here is his Sunrise, with a Boat between Headlands, c. 1835-40.

This wisdom works where there are strong westerlies, which happen in the middle latitudes (in which both Jerusalem and Rochester fall). Of course, I also use NOAA’s website; their hour-by-hour weather graph is the plein air painter’s best friend.

I have three openings left for my 2014 workshop in Belfast, ME. Information is available here.