Summer’s record-busting hot, dry conditions are likely to extend into autumn, according to the latest long-range weather forecasts.
The weather bureau’s outlook for autumn, released this week, predicts warmer than average days and nights across almost the whole country from March to May.
During the day there will be an 80 per cent chance of above-median temperatures, the Bureau of Meteorology (BoM) predicted.
“These warm outlooks follow Australia’s warmest December and January on record.”
BoM said it predicted a 50 per cent chance of an El Nino developing during autumn – double the normal chance. El Nino events typically bring drier than usual autumns to southern Australia.
However, the US National Weather Service says El Nino has already developed in the Pacific Ocean. The USNWS expects that pattern to continue for the next three months.
Commercial forecaster Weatherzone says Australia and the US use different thresholds to define El Nino and La Nina (which brings wetter than average seasons). Australia’s thresholds are higher than those of the US.
“There’s no doubting that the Pacific Ocean is in an El Nino-like pattern, and this could influence Australian rainfall during the coming months,” Weatherzone said.
The weather bureau’s outlook warns that Australia’s climate patterns are being influenced by the long-term increasing trend in global air and ocean temperatures, as well as the natural El Nino drivers.
It also predicts a below-average rainfall for northern Australia – parts of which are still recovering from a record soaking that brought devastating floods.
“In contrast, most of southern Australia shows no strong swing towards either a wetter or drier than average autumn,” the BOM said.
“However, in southern, and particularly south-eastern Australia, recent years have seen a decline in the average autumn rainfall.”
First look at #BOMOutlook:
No strong likelihood of either wetter- or drier-than-avg conditions in southern #Australia, but recent autumn breaks have tended to be late.
Northern Aus likely to be drier than avg.
Warmer than avg likely across the country.https://t.co/THUcDGOB5y pic.twitter.com/eetiFfVDbe
— Bureau of Meteorology, Australia (@BOM_au) February 13, 2019
The bureau says there has been below-average rainfall in south-eastern Australia in 24 of the 29 years since 1990.
“While southern Australia shows little shift towards wetter or drier conditions, the past two to three decades have seen a decline in autumn rainfall,” its forecast says.