I’ve noticed that when barometric pressure drops this is usually followed by bad weather and vice versa. I’ve always thought that when rain is approaching this means humid air which has water vapour molecules in it (so it must be heavier than dry air?) thus higher pressure reading on the barometer because heavier air is exerting more force on the Earth’s surface. I’m clearly wrong here but couldn’t find a clear explanation as to why.
In: Physics
Low pressure means the air is less dense and warmer than the surrounding air (doesn’t ha e to mean it’s warm). That will cause the movement of gas from area of higher pressure/lower temperature to move towards it . The warmer air has more energy and more moisture – when it meets colder air, the moisture might condense (depending on the temperature) and turn into clouds, precipitation etc etc.
It indicates a low pressure system which is an area of higher winds and possibly but not always wetter weather.
why do cows lie down before a rainfall?
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