Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are an everyday phenomenon which, along with anticyclones, drive the weather over much of the Earth. They are capable of producing anything from cloudiness and mild showers to heavy gales and thunderstorms. These types of cyclones are defined as synoptic scale low pressure weather systems that occur in the middle latitudes of the Earth (outside the tropics) not having tropical characteristics, and are connected with fronts and horizontal gradients in temperature and dew point otherwise known as "baroclinic zones".