A “wintry blast” is forecast to hit south-eastern Australia this weekend, while the Bureau of Meteorology also announced the development of a negative Indian Ocean Dipole (IOD), which could bring further heavy rain in the coming months.

Bureau meteorologist Jonathan How says two cold fronts will sweep through from tomorrow, bringing high winds, rain, dangerous seas and alpine blizzards.

Warnings are current for parts of Victoria and NSW for damaging winds strengthening above 90kmh, and there’s also a warning for abnormally high tides along some areas of the Tasmanian coast.

“There is some minor flooding about and catchments will respond quickly to further rain,” Mr How says in a video update.

“Coastal communities should also brace themselves for dangerous seas as waves exceeding six metres pummel the coast.

“Combined storm surge and abnormally high tides will create hazardous conditions really only seen once a year that may lead to coastal erosion and inundation.”

The Bureau says the negative IOD will increase the likelihood of above average winter-spring rainfall for much of southern and eastern Australia.

“Most climate models surveyed by the bureau predict a negative IOD pattern is likely to persist until at least mid-spring,” the latest climate driver update says.

The IOD Index, which reflects differences in sea surface temperatures between the eastern and western tropical Indian Ocean, has been below the IOD threshold for eight of the past nine weeks, reaching the point at which an event is declared.

The Insurance Council of Australia last month declared a catastrophe for floods and storms across Victoria, with 20,000 claims leading to insured losses of $182 million so far.

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