Weather Maps

Features and their most common weather characteristics found on surface weather maps:

The general movement of weather systems are from West to East.

Isobars;

Isobars are lines on a weather map, connecting points of equal atmospheric pressure.

When isobars are spaced far apart then the pressure changes more gradually over distance and thus the wind speed is weaker.

When isobars are spaced closer together then the pressure changes less gradually over distance and thus the wind speed is stronger.

Anticyclone (“high”);

In the Southern Hemisphere, an anticyclone, or high, is an atmospheric pressure system in which there is a high central pressure relative to the surroundings with an anticlockwise circulation of winds.

• Air sinks down.
• It has higher pressure at its center than the areas around it.
• The winds blow out away from high pressure.
• A blue H denotes the location of a high pressure system.
• characterised by fine weather with light winds

It is characterised on a synoptic chart by a system of closed isobars, generally approximately circular or oval in form, enclosing the central high pressure.