Canty unlikely to have summer drought

23:41, Oct 07 2012

A fizzer of an El Nino means Canterbury is unlikely to face a summer drought.

Instead, average weather - a normal mix of bracing easterlies, warm nor'westerlies and colder southerlies - is more likely.

The El Nino atmospheric pattern that brings drier than normal weather and long spells of strong west to southwest winds to the South Island's east coast looks to be fading before it has even properly begun.

The National Institute of Water and Atmospheric Research (Niwa) says the El Nino is "borderline" and appears unlikely to strengthen through the remainder of spring or be anything other than short-lived.

Senior climate scientist Georgina Griffiths said warmer sea temperatures in the Pacific Ocean were a reflection of weak El Nino conditions in the ocean.

However, the atmosphere had not moved into an El Nino phase yet.


"The Pacific Ocean's been trotting along at borderline thresholds for a while but it hasn't coupled up with the atmosphere," she said.

"When they don't couple, it's like it doesn't get the kick it needs to start, so it doesn't have the hallmarks of a major El Nino."

Spring was traditionally changeable, with periods of west to southwesterly winds, which could give the impression of an El Nino, she said. "So it looks a bit El Nino-like at the moment but it's just spring."

Niwa principal climate scientist Brett Mullan said global computer models had now weakened El Nino predictions, relative to forecasts from August.

"While the El Nino is looking a bit of a fizzer at the moment, we can't count it out entirely just yet," he said.

Niwa's seasonal prediction for Canterbury for October to December is for near-average to above-average temperatures and average to below-average rainfall, soil-moisture levels and river flows.

Sea-surface temperatures are expected to be warmer than normal around the South Island, and cooler than normal to the east and north of the North Island.

The Press