What is an east coast low?
* An intense low pressure system that forms in the Tasman Sea.
* East coast lows drive high winds, heavy rain and dangerous surf into coastal areas of NSW, southern Queensland and far eastern Victoria
* They tend to be most frequent in autumn and winter, and particularly in June
Why east coast lows cause bad weather
* East coast lows draw strong, moisture-laden winds across the coast, which cause heavy rain to fall when they are uplifted by the hills and ranges that run parallel to the coast
Are they dangerous?
* They can cause gales or storm force winds that can damage buildings, fell trees and powerlines, cause powerful surf that can damage the coast and, in some cases, run ships aground
* They can also dump hundreds of millimetres of rain, causing flash flooding and riverine flooding
Other east coast lows
* June 2007: Bulk carrier Pasha Bulker runs aground near Newcastle amid wind gusts up to 124km/h
* October 2004: Mean wave heights off Sydney of 5m with a maximum height of about 10m
* August 1998: More than 300mm of rain over four days in Sydney and Illawarra, 420mm at Beaumont and 401mm at Kangaroo Valley
* May 1974: 165km/h gust at the Newcastle Nobbies, bulk carrier the Sygna runs aground
* August 1857: The Dunbar wrecked at South Head, 121 dead and one survivor
(Source: Bureau of Meteorology)
