I was having a quick look around for information on the size and frequency of severe storm events like the one we have just experienced. I cam across this document, and thought that others here may be interested in it.
http://www.goldcoast.qld.gov.au/documents/bf/storms-east-coast-1770-2008.pdf
http://www.goldcoast.qld.gov.au/documents/bf/storms-east-coast-1770-2008.pdf