Southerly is the name of a storm or front of air coming from the south. In the southern hemisphere these can be cold and have bad weather. In Wellington, New Zealand these storms are normally short and frequently have winds gusting between 120 km/h and 160 km/h though higher speeds are known. In Sydney, New South Wales, Australia these events are known as southerly busters. On sunny days in the Sydney Summer, the land heats up rapidly during the morning, while sea temperatures remain cool, typically 20 to 23 degrees. The prevailing early morning wind is a light south-west offshore breeze (a catabatic wind) that blows from land to sea, but as the land heats up a north-east convection wind develops. This is a typical "sea breeze". It starts shortly after sunrise on the coast and gradually pushes inland as the day proceeds, typically reaching the City by mid to late morning and the Western Suburbs by early to mid afternoon.