What are the general areas of high and low pressure?

Answer 1

High pressure is dry air; low pressure is moist air. The reason: the molecular weight of water vapor is less than the average molecular weight of the gasses in dry air. So, a column of moist air weighs less than dry air and exerts less pressure on the ground. Moist air forms over water, and evaporation is highest where the temperature is the warmest. Dry air forms over continents, so the bigger the land area, the drier the air.