why do clouds form at low pressure areas, but not high pressure areas?

Answer 1

In a low pressure zone, air flows into the area of low pressure and then rises. As the air rises, it cools, and any moisture in it will turn into clouds.

In a high pressure zone, air is flowing down.

Answer 2

High Pressure Areas

Answer 3

At surface levels, more air flows into a low pressure region than the air that flows out.This is called convergence.In a high pressure region, more air flows out than that which flows in.To compensate for the excess or deficiency of air at these regions ,air has to ascend or descend.
In a low pressure region the excess air that flows in is forced to rise above.When this upward flowing air cools by expansion or due to low temperature above,the air can no longer contain all the water vapour it holds with the result that some of the vapour condenses into cloud droplets forming a cloud.
At high pressure areas the winds descend.The pressure gradient is also small with the result winds are light.Weather is usually fair in summer.However, in winter if conditions are favourable for formation of radiation fog,thick fog forms sometimes and it is lifted up to form thick clouds creating an 'anticyclonic gloom' in the northern hemisphere.

Answer 4

It is all relative. Clouds can form in high pressure, but there has to be a higher % of water vapor present.
It has to do with something called 'partial pressures' and the 'perfect gas law'.

Condensation of atmospheric moisture occurs when:

1) the volume of air remains constant but temperature is reduced to dewpoint, e.g. contact cooling, mixing of different layers
2) the volume of an air parcel is increased through adiabatic expansion
3) evaporation increases the vapour partial pressure beyond the saturation point
4) a change of both temperature and volume reduces the saturation vapour partial pressure

Answer 5

Low pressure causes air to rise, as it rises it expands and cools and eventually at some point, condenses into water vapor. The opposite is true of high pressure. The descends and as it does so, is compressed and water vapor becomes less and less likely.