El Nino cooling, but Australia faces increased chance of bushfires: BOM

December broke heat records across large parts of South Eastern Australia, and El Nino conditions mean there is a heightened chance of bushfires this summer.

Firefighters at a fast moving grass fire in the Epping area in the northern suburbs of Melbourne

Firefighters at a fast moving grass fire in the Epping area in the northern suburbs of Melbourne Source: AAP

Large parts of southeastern Australia received record temperatures in December, and the Bureau of Meteorology (BOM) warns the continued El Nino conditions this summer mean heightened chances of bushfires this festive season.

On Wednesday morning, a BOM representative in Adelaide said the eastern parts of South Australia would have an increased risk of bushfires.

Christmas Day in South Australia will be hot - 37 degrees - the BOM representative said.

"What will be a pleasant warm, even hot Christmas Day will be caught up with some blustery winds as we see the afternoon and evening move through," the BOM representative said.

"Even as it gets cooler but the winds come up, we see the most dangerous fire conditions."

December this year broke records, Wednesday's  says.

Adelaide had four consecutive days where the mercury reached 40° C - the first time in recorded history to occur in December.

"Mildura recorded the highest minimum temperature ever observed at a Victorian site and a number of other locations in northern Victoria had their hottest night on record for any month," the BOM's report says.
December climate record
Large parts of South Eastern Australia had record temperatures in December. Source: Bureau of Meteorology
Earlier this month, the BOM warned of increased bushfire risk in their .

"Heatwave and bushfire risks are raised in any El Nino summer," the BOM's outlook said.

The outlook said Australia had received above-average rains in November, yet, large parts of Australia are still in drought and Australia is going into the new year with less water in many agricultural areas.

"Areas of short-term rainfall deficiency are now widespread," BOM said.

Could cooling in the Pacific shorten the El Nino?

Recent cooling below the surface of the Pacific Ocean may diminish the shelf life of the El Nino event that has plunged parts of Australia into drought.

The Bureau of Meteorology says the El Nino, a warming of sea surface temperatures in the central and eastern tropical Pacific that tends to bring drier weather to Australia, remains strong and is near its peak.

But some below-surface cooling has occurred in the eastern tropical Pacific over the past fortnight, the BOM's latest says.

"Changes in the sub-surface are an important indicator, as the sub-surface plays a significant role in maintaining the strength and longevity of El Nino events," the report said on Tuesday.

The below-surface ocean temperatures are still significantly warmer than average.

This year's El Nino event is one of the strongest on record, matching the strength of record El Ninos in 1997/98 and 1982/83.

Both of those events brought severe droughts to eastern Australia, and the 1982/83 drought was a major factor in the Ash Wednesday bushfires that killed 71 people in Victoria and South Australia on February 16, 1983.

The influence of El Ninos varies at this time of year, depending on how quickly they begin to break down, but most deliver below-average rainfall and a continuing drying influence on southeastern Australia but more rain in inland Western Australia.

Models suggest the event will start to decline in 2016, but the tropical Pacific is unlikely to return to neutral until at least autumn.

Meanwhile, a warming of Indian Ocean sea surface temperatures known as the Indian Ocean Dipole may provide extra moisture for rain systems across Australia.


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3 min read
Published 22 December 2015 8:32pm
Updated 23 December 2015 1:36pm
Source: AAP, SBS News


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