Does the weather proverb "Red sky at...

The basic idea here is a sound one for most of the United States, where the weather patterns move from west to east. A red color in the sky is the result of sunlight reflecting off clouds. If the sky is red in the morning, the eastern horizon must be clear, and the clouds foretelling a coming storm are in the west, indicating the potential for bad weather. By contrast, a red sky at night can be produced only if the western horizon is clear and the clouds overhead are moving east, or clearing out. So the proverb seems to have some validity.