What indicates high-pressure systems in terms of air rotation?

High-pressure systems are characterized by clockwise rotation in the Northern Hemisphere due to the Coriolis effect, which arises from the Earth's rotation. In these systems, air descends from higher altitudes and moves outward at the surface, causing the air to spiral outward in a clockwise direction. This outward motion creates divergence at the surface, which is associated with clearer skies and fair weather conditions.

In contrast, low-pressure systems exhibit counterclockwise rotation, which is where air converges and rises, often leading to cloud formation and precipitation. The distinct behaviors of high and low-pressure systems are critical for weather prediction, as they determine wind patterns, temperature changes, and precipitation likelihood in various regions. Understanding the rotation of these systems is essential for pilots when assessing weather conditions during flight.