AS temperatures in Canberra plumbed minus 5.8C this morning, frozen locals may be surprised to learn that the warmer, drier El Niño weather conditions may be on the comeback.

Tom Saunders, senior meteorologist at The Weather Channel, says that after two years of record rain and flooding, Australia’s weather patterns are taking a dramatic turn.

“Sea surface temperatures through the central tropical Pacific Ocean have gradually warmed during the past few months and are now more than 0.5°C above average, passing the threshold for El Niño conditions,” he says.

“Extensive warming through the Pacific Ocean causes a major shift in weather patterns throughout the world and for Australia, causes below average rain and drought-like conditions.”

Other El Niño indicators are also emerging including a current Southern Oscillation Index (SOI) of -10 and weaker trade winds through the western Pacific. Sustained negative SOI values below ?8 can indicate an El Niño event.

“For a fully fledged El Niño episode, temperatures must remain at least half a degree above average for at least five months, but climate models predict the warming trend will continue over the coming months,” Saunders says.

“El Niño conditions typically bring below-average rain and above-average temperatures to the eastern half of Australia during winter and spring, and this is already being reflected in seasonal outlooks which forecast dry weather for most of the country,” says Saunders.

“Following Australia’s wettest two-year period on record, much of the country has seen substantial vegetation growth. Dry, hot weather associated with El Niño could therefore not only bring drought, but also lead to a devastating bushfire season due to the increased fuel load,” he concludes.

The last El Niño was in 2009 and caused near-record low rain through winter and spring across much of Queensland and the NT. A more devastating El Niño during 2006 brought the driest weather on record to many parts of southern Australia.

Unlike La Niña events, the effects of an El Niño typically do not carry on through summer except across the northern tropics.