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Red Sky at Night

This week’s blogpost is written by Gabe, a monthly correspondent and Ursids alumnus. He analyzes the sunsets and explains why they are a little more than a pretty sight! Read more to find out how the sunset can predict the future! 

Red sky at night, sailors’ delight. Red sky at morning, sailors take warning.

A phrase passed down from generation to generation; truth or fallacy?

Sunsets are a thing of beauty. They are breathtaking scenes that everyone can enjoy. When we see a red sky at night, it means that the sun is sending its light through a high concentration of dust particles and water vapor. This, for the most part, is indicative of a high pressure system and smooth, stable air coming from the West. This means good weather!

Weather moves west to east, which means storm systems generally move in from the west. Since, the storm systems come in from the West and they are commonly low pressure systems, the high pressure system coming in instead indicates good weather.

Why are these pressure systems so important? If you look at a map of surface pressure, you will see alternating areas of high low pressure.  That is because pressure patterns are relative. This is because in a region of lower pressure, there must be higher pressure on either side. Low pressure causes air to converge, that is, air is trying  to fill the low, and converging air causes upward motion, which in turn produces clouds and precipitation (i.e. rain, snow, etc.). On the other hand, air diverges from the center of a high-pressure area. This causes downward motion, which suppresses cloud buildup and forces water vapor and dust down closer to the lowest level of the atmosphere.

Picture taken at Covington Lake, Covington Township PA