“Indeed, we skipped the fall. We had this wet weather that continued for a few months and all of a sudden it was winter,” he says. “We didn’t have that intermediate period that we had for several seasons.”
He says meteorologists don’t use terms like “polar explosion,” though he acknowledges that a low-pressure system rising from the southwest has created a surprising climate in many parts of the country.
South Australia recorded a small tornado that hit the northern suburbs of Adelaide on Monday afternoon. Snow has fallen from Tasmania in the central highlands of NSW, and South Queensland suffered winds of 90 km / h while shaking below average monthly temperatures.
The La Nina system caused flooding in Queensland and NSW earlier this year, and is now expected to continue this winter until next summer. Credit: Getty
Professor Roger Stone, an international leader in climate science at South Queensland University, says the La Niña weather system that caused the devastating rains earlier this year is another factor in the sudden pot of cold.
“La Niña tends to delay the start of the frost season, in fact it makes it a very short season,” he says.
“La Niña still governs our general weather patterns: she is responsible for our flood rains and she is responsible for this current climate.”
Instead of an isolated cold system, Stone says the current cold weather is part of La Niña’s biggest pattern that is now expected to last next year.
This will flatten the temperature ranges this winter, with daytime highs being colder than average, but nighttime temperatures warmer than average in most parts of South Australia.
Stone says this also means more rain throughout the winter and next spring and summer, increasing the spectrum of more flooding like those seen earlier this year.
“We see this pattern of La Niña spread about four times a century, and in fact we saw it in 1955-56 where there were floods, in 1974-75 when there were big floods in Brisbane, in 2000-2001 and in 2010. -2012 when there were floods, a long La Niña that caused floods “, he says.
“So the risk is there again for another rainy summer; we still don’t know how intense it will be, which will determine if we see flooding as we saw earlier this year.”
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