An Australian navy ship is on its way to rescue a Lithuanian man rowing from San Diego to Brisbane after he was caught up in Tropical Cyclone Alfred.

Tropical cyclone is the catch-all term for the powerful, spinning storms that feed off warm oceans and the strength of which is determined by wind speeds. The strongest are known as hurricanes in the Atlantic and typhoons in the Western Pacific and simply tropical cyclones in the South Pacific.

The unusual activity is "a lot to happen at once, but not unprecedented," an atmospheric science professor said.