Help me understand what a barometer reading on a weather forecast means and how it predicts the weather?


2 Answers

HappyTo BeHereTo Profile

I'm no expert, but here's the basics as I understand it.  I think of the Earth like a casserole.  It's not perfectly even all over the world.  There are pockets of granite here and sandstone there, like there are gooey cheesy bits here and meat there. 

Same with the air.  It's thick here and thin there. 

The barometer reads the current air pressure.  It doesn't predict the weather.  Gravity pulls everything down, even air.  The barometer measures how much pressure is being exerted on us.

The sun warms the Earth.  Warmed air from the surface rises.  When the pressure is high, the air can't rise to the upper troposphere and lower stratosphere  where clouds are formed.  When we are under high pressure, we are less likely to see rain clouds form.  The opposite is true when we have low pressure.

When high and low pressure collide, we are more likely to see storms.  Our casserole bubbles over and we have to clean the oven.

Tom  Jackson Profile
Tom Jackson answered

Here's a quote from a great internet site that will give you a good short overview of what tends to happen when we are under low and high pressure conditions.

"Now there is much more to it than just high pressure = nice weather and low pressure = bad weather (otherwise I would be out of a job!), but hopefully after reading this, you have a better understanding of why meteorologists talk about pressure systems."

3 People thanked the writer.
Danae Hitch
Danae Hitch commented
I always learn something when you answer, Tom. Thanks.
Tom  Jackson
Tom Jackson commented
You're quite welcome Danae Hitch---I try to be informative.

I have numerous and various interests in my life and the opportunity (some might say obsession) to pursue pretty much all of them.

That gives me a certain advantage when searching for sites that best explain what the person is asking.

Answer Question