The reason for the higher flood risk is because of a weather event predicted by the Bureau of Meteorology: La Nina.
It essentially means more rain for the east and south of the country - and lots of it - for the rest of spring and into summer.
Dr Andrew Watkins is the weather Bureau's chief long range forecaster.
"A La Nina event is when we see cooler than normal temperatures in the tropical Pacific Ocean, and these changes in the temperatures of the ocean cause changes in the weather patterns right around the globe. For Australia that typically means that we get wetter than normal conditions, particularly in the spring and early summer."
Professor Howden says La Nina - the girl child, in Spanish - can be thought of as the opposite phase of the hotter, drier weather trend known as El Nino - the boy child.
"We often talk about those together, and it's where the trade winds across the Pacific either strengthen or weaken. And what that does is it allows large amounts of cold water or warm water to move across the Pacific Ocean from the Americas. So typically in an El Nino you've got a huge amount of warm water stretching across the Pacific Ocean and in a La Nina like this year we've got a huge amount of cold water. And that piles up the warm water next to Indonesia and the Philippines, some of which flows down around Australia, and that tends to bring us much wetter conditions than we normally would have."
La Nina is a naturally occurring weather pattern. It's the third such event Australia has experienced in recent decades.
