By Susan Sandys  November 23 2009

An “oddball” El Nino pattern in the Pacific will deliver extreme weather to Mid Canterbury this summer, says Tony Trewinnard of Blue Skies Weather.

But whether that will be drought or too much rain is impossible to tell at this stage, due to the El Nino’s behaviour making it difficult to tell which way it will swing.

 “This would have to be one of the least predictable El Nino weather patterns I have seen in the last 25 years, it really is an oddball one,” Mr Trewinnard said.

 Mr Trewinnard said the El Nino’s variables of wind flows, ocean currents, movement of weather patterns were not tying in with each other in the way they would in a typical El Nino.

 If the El Nino dominated over summer it would ward off westerly weather patterns and this would cause wetter and cooler weather than usual, whereas if it peaked and then tailed off it would cause drier and hotter weather, possibly leading to drought in Canterbury.

 For the next six weeks he expected the El Nino to weaken slightly, causing predominantly fine and drier than normal weather, but after that it was hard to tell.

 Mr Trewinnard said the phenomenon behind the strange El Nino may be the same one causing extreme weather in other parts of the world, such as floods in England and bushfires in Australia, but it was not climate change as most understood it.

 It was instead “a very quiet sun” with lessened radiomagnetic output.

 Some research suggested it was the lowest output for at least 100 years, and the longer this went on for the more extreme the earth’s weather could become.

 “We may be in a period when climate is altering naturally around the world possibly due to solar influence,” Mr Trewinnard said.

 The effects had been seen in Mid Canterbury in the past 12 months, with several weather events making the news.

 August was the hottest on record, October the coldest for decades, while other months have featured hail and wind.