because those giant H’s and L’s representing high and low air pressure systems on a weather map are meaningless without understanding their significance. HELP FROM HIGH PRESSURE: How Houston's ...

However, those H’s and L’s are not marking the position of high and low pressure ... have drawn weather maps describing upper air conditions using constant pressure surfaces.

High pressure often represents stable air, while low pressure can signify instability. On a cold, sunny day there will be a significantly higher atmospheric pressure than when a big storm is ...