Barometers are used to determine the pressure in the atmosphere, so that we’ll know what type of weather to expect. Early barometers were referred to as "weather glasses" and, when they fell, this would indicate that a storm was approaching.
Sometimes, a low pressure system is the result of a backing wind, which is the term that’s used for winds which begin in the west and move in a counterclockwise direction, to inevitably result in a southeasterly wind. These types of winds indicate that a low pressure cell is moving in, foretelling a storm. This old adage expresses it quite well:
"When the wind backs and the weather glass falls, prepare yourself for gales and squalls."
High air pressure, on the other hand, is typical of fair weather, so when the barometer – or wind glass – rises, then good weather is on the horizon. Sometimes, the quality or scent of the air speaks for itself. For instance, while high pressure tends to keep the natural scents of the earth (plants, soil, etc.) close to the ground, a low pressure system will release their fragrances into the air, as expressed in this old saying:
"When the ditch and pond affect the nose, look out for rain and stormy blows."
Have you ever heard someone say that they know when it’s going to rain because the corns on their feet ache? Well, that’s not an old wives’ tale! When the barometer falls – indicating an approaching storm – a number of people experience aches and pains in these problem areas, which has precipitated the saying:
"If your corns all ache and itch, the weather fair will make a switch."
It’s no coincidence that fish will start jumping when rain is approaching. When the barometric pressure falls, gases are sometimes trapped on the bottom of a pond or lake, causing debris from decaying plants to disperse. When this happens, tiny organisms that hide within the plant matter are flushed into the surrounding waters. As a result, the fish that are present go on a feeding binge and become quite active, due to their excitement at discovering such abundant food in the waters all of a sudden. Therefore, a lot of jumping and splashing will be noted when there’s an impending storm, hence the lore: