What does high and low pressure mean on weather maps?

[Swede]

And how does it affect local weather?
High assume is warm air and low is cool,but I could be wrong. :shrug:

[XemaSab]

1. High and low have almost nothing to do with warm or cool

It has to do with whether the air is sinking or rising vertically. :hi:

[HopeHoops]

2. There's a simple rule...

If there's a big circle around where you are with an "L" in it and a bunch of wavy lines with an "H" on the other side and the radar map shows a shitstorm from hell under the "H", it is time to hide because that shitstorm is heading your way.

In more general terms, whatever is going on in the high pressure areas is going to try to find its way into the low pressure areas to equalize the pressure. In practice that doesn't really ever happen completely but it does guide the direction of the fronts (which is where temperature comes in). That's why when the barometer starts to drop you should prepare for the possibility of a storm since you've become a target for any nearby high pressure area.

[underpants]

3. High pressure is generally nicer weather

[rurallib]

5. except in the winter when it's one of them damn highs Canada sends

down to torture us. Then it gets near as cold as George Bush's heart.

[datasuspect]

4. this is all you need to know

when we offend G-d, bad things happen.

when we propitiate G-d, good things happen.

[Jimbo S]

6. In general.

High pressure means air is sinking, usually leading to warm weather. Akin to a bike tire warming up when pumping air into it. Air flows clockwise around a H in the northern hemisphere.

Low pressure forms when air rises, and when air rises clouds will form. Fronts usually form out of low pressure systems.