Southerly
Encyclopedia
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.
In the hot Sydney summer, the land heats up rapidly each morning, and faster than the sea. The prevailing wind is a light south west offshore breeze that blows from land to sea, but by mid to late afternoon, the land rapidly cools and a north east convection current wind sweeps in from sea to land. This is a typical "sea breeze", but often it is strong offsea gale bringing a rapid fall in temperature, and a short, violent rain/hail storm.
A more persistent but potentially violent Sydney NE storm is known as a "black nor'easter" . This is not a convection wind, but a storm system that develops offshore which can last several days. This is heralded by the rapid build-up of dense black cloud that can convert to a gale in well under one hour.
Occasionally, when there is a strong colder system to the south west, the temperature is dramatically broken by an equally violent storm-laden south west wind, and it is this that is known as a "southerly buster".
All these wind storms have been known to cause widespread damage onshore, and to sink small craft on the water. Yachtsmen on Sydney Harbour in the summer know to keep looking at the flags near Garden Island Naval base for the black flag that warns of these strong winds, to listen to the Marine Weather Channel 67 VHF and to watch for the "Roll Clouds" that precede the cold front ahead of a cold southerly change.
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
these can be cold and have bad weather. In Wellington
Wellington
Wellington is the capital city and third most populous urban area of New Zealand, although it is likely to have surpassed Christchurch due to the exodus following the Canterbury Earthquake. It is at the southwestern tip of the North Island, between Cook Strait and the Rimutaka Range...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
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
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
, New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
these events are known as southerly busters.
In the hot Sydney summer, the land heats up rapidly each morning, and faster than the sea. The prevailing wind is a light south west offshore breeze that blows from land to sea, but by mid to late afternoon, the land rapidly cools and a north east convection current wind sweeps in from sea to land. This is a typical "sea breeze", but often it is strong offsea gale bringing a rapid fall in temperature, and a short, violent rain/hail storm.
A more persistent but potentially violent Sydney NE storm is known as a "black nor'easter" . This is not a convection wind, but a storm system that develops offshore which can last several days. This is heralded by the rapid build-up of dense black cloud that can convert to a gale in well under one hour.
Occasionally, when there is a strong colder system to the south west, the temperature is dramatically broken by an equally violent storm-laden south west wind, and it is this that is known as a "southerly buster".
All these wind storms have been known to cause widespread damage onshore, and to sink small craft on the water. Yachtsmen on Sydney Harbour in the summer know to keep looking at the flags near Garden Island Naval base for the black flag that warns of these strong winds, to listen to the Marine Weather Channel 67 VHF and to watch for the "Roll Clouds" that precede the cold front ahead of a cold southerly change.