It has been a good year for Australian global warming believers. Temperatures over the last year have been hotter than normal over most of the continent with mean maximum temperatures up to 1.5 degrees higher than recorded over the long term.
The Australian Bureau of Meteorology expects that the trend might not continue this summer except for the south eastern corner taking in southern NSW, Victoria, Tasmania and part of South Australia. The Bureau’s latest climate outlook for maximum temperatures averaged over summer (December to February) shows a moderate shift in the odds favouring warmer than average conditions in southeastern Australia but cooler daytime temperatures are favoured in southern Queensland and northeastern NSW.
“The pattern of seasonal temperature odds across southern Australia,” says the Bureau, “is mostly a result of continuing higher than average temperatures over parts of the tropical and sub-tropical Indian Ocean. The La Niña pattern of cooler than average temperatures in the central to eastern equatorial Pacific has contributed to the increased chances of cooler than average daytime temperatures in southern Queensland and northern NSW.”
While Western Australia and north eastern Queensland are predicted to avoid hot days, they can look forward to warm nights. The chances of increased overnight warmth (averaged over the coming three months) over much of the southern half of WA are greater than 60%, reaching above 80% over a large area. Cape York Peninsula in Queensland has values in the 60 to 65% range, while the chances in remaining parts of the country are in the 40 to 60% range.
To put the warmth of the last year in to a broader perspective, the Bureau has produced the following chart showing mean temperature anomalies back top 1910.