The atmosphere moving very slowly in huge blocks of air is called high-pressure systems.

Here's why:

* High-pressure systems are areas where the air is sinking. This sinking air creates a high pressure at the surface.

* Sinking air is associated with clear skies and calm, dry weather. This is because the air is descending, it compresses and warms, inhibiting the formation of clouds and precipitation.

Let me know if you'd like to learn more about high-pressure systems!