atmospheric river

This is another name for what we have called a cloud band which Macquarie defines as ‘a cloud formation which is a nearly continuous band of cloud stretching for up to hundreds of kilometres’.  The difference between an atmospheric river and an ordinary cloud band is that they are extremely narrow, possibly only a few hundred kilometres wide though stretching for several thousand kilometres.  They drag water vapour from the tropical oceans and carry it along the plume until it reaches the coast where the moist air rises and the rain falls down in an extreme precipitation event.

In Australia we mostly get atmospheric rivers in the northwest which originate in the Indian Ocean and bring heavy rainfall to the northwestern central and southeastern parts of the country.  But we also have them on the eastern side.