Identifying Features on Contoured Maps

On surface charts, we often contour isobars

This allows to identify key features at the surface like:

• • Surface high pressure systems

  • Surface low pressure systems

  • Weather fronts

  • Wind direction

On upper-level charts, we often contour isoheights

This allows to identify key features at the surface like:

• • Troughs: elongated areas of low pressure

  • Ridges: elongated ares of high pressure

  • Wind direction