"the lowest 500-mb heights are generally associated with the latitude stations. these upper air features result from cooler temperatures in the air column between 500 mb and the surface."

The height shapes on the map are really the height of the 500 mb weight surface in meters above ocean level. The normal pneumatic stress close to the ground is around 1000 mb, and since gaseous tension abatement as one moves upward, at some elevation the pneumatic force will tumble to 500 mb. The least 500-mb heights are for the most part connected with the most elevated scope stations, meaning the highest. These upper air highlights result from cooler temperatures noticeable all around section between 500 mb and the surface.

Uncle grandma