Pat Shingleton:"What About Those Old Sayings"
Prior to the assistance of satellites, radar or other technological advances, folks would rely on the sky, plants and animals for weather predictions. Success in matching nature with weather expectations also created a variety of weather expressions an folklore. You've heard the old adage: "Red sky at night, sailor's delight...Red sky in the morning, sailors take warning." Close to sunset, the western sky is especially clear, creating beautiful red sunsets. As the sun goes down it bops through the lower atmosphere, hitting scattered particles of dust, smoke and pollution. In this "scattering" process the shorter wavelengths of light, depicted as violets and blues, are eliminated with the longer wavelengths of reds and oranges remaining. Sinking air gathers the contaminants closer to earth, making the sunset even redder. This is caused by high pressure that brings fair weather. If the eastern sky is red in the morning, high pressure has passed, replaced by low pressure, clouds, rain and possibly hefty thundershowers, that we have experienced recently. "Mare's tails and mackerel scales make tall ships take in their sails." This adage refers to the sky. Sailors of old could only rely on the sky, wind and wave heights to determine their weather. A mackerel sky means that cirrocumulus clouds are present. These cloud types occur prior to a warm frontal passage. An approaching warm front shifts the winds from northeast to east then southwest and west. This would require the captain or skipper of the ship to reef or take in their sails. "Clear moon, frost soon," suggests that the earth will cool rapidly as daytime heat escapes at night. With limited or no cloud cover, there's no blanket to hold the day's heat close to the surface. As the temperature drops and winds subside, the falling temperature will create the frost.