Chances increase for above-average winter rainfall

Local weather drivers within the Pacific and Indian oceans are pointing to an elevated probability of above-average winter rainfall in japanese Australia, the Bureau of Meteorology says.

The bureau says all of the local weather fashions it surveys counsel a adverse Indian Ocean Dipole (IOD) might develop within the coming months, whereas two of seven fashions say La Nina situations might proceed by the southern winter.

“Even when La Nina eases, the forecast sea floor temperature sample within the tropical Pacific nonetheless favours common to above-average winter rainfall for japanese Australia,” the Local weather Driver Replace says at present.

A adverse IOD is related to the prospect of above common winter-spring rainfall for a lot of Australia, in addition to hotter days and nights within the north.

“Whereas mannequin outlooks have low accuracy right now of yr and a few warning must be taken with IOD outlooks, there’s robust forecast consistency throughout worldwide fashions,” the bureau says. “Outlook accuracy for the IOD begins to considerably enhance throughout June.”

The IOD is the distinction in temperatures between the west and east tropical Indian Ocean, which might shift moisture in direction of or away from Australia.

Damaging phases usually tend to coincide with a La Nina and may have an effect from Could to December, the bureau says. Australia had its wettest yr on document in 1974 when a adverse IOD coincided with a La Nina.

The present La Nina, which has introduced heavy rainfall and catastrophic flooding to NSW and Queensland, is the second in two years. Consecutive occasions have been beforehand seen in 2010-2012.