©VANCOUVER PROVINCE – FRIDAY, OCTOBER 12, 2007

La Nina could mean winter will be colder and wetter
By Clare Ogilvie

Whistler – La Nina is here and that’s likely to mean wetter and colder winter weather in most of BC and Canada

“It was declared this week,” Environment Canada’s David Phillips said yesterday.

“It’s a legitimate La Nina and the models are all saying it is weak, but it is going to strengthen to a moderate-size event, and the more intense it is the more likely it will be colder and snowier.”

But La Nina will butt heads with climate change and that means the West Coast is likely to see a “normal” winter with considerable snow at higher elevations, some snow in Vancouver and coastal cities, cool temperatures and lots of rain.

“But that normal winter may feel pretty tough,” said Phillips, following as it does on the heels of several years of warmer winters.

“It is almost as if the models are sensing both the La Nina situation and the climate change situation and call for near normal.”

The last two La Ninas to hit BC did not behave typically. From 1998 to 2000 the weather was warmer and wetter than expected for a La Nina event. And in the 1995-96 La Nina, the weather was normal. But in the eight previous ones going back to 1950, most were colder and wetter.

“Because the last two were strange ones, kind of out of sync, it leaves more uncertainty,” said Phillips.

La Nina is a period of strong trade winds and unusually low sea-surface temperatures in the central and eastern tropical Pacific. It can affect weather patterns around the world.
Allan Chapman, head of the government’s River Forecast Centre, said that it’s too early to tell if this La Nina will mean a higher risk of spring flooding as the snowpacks melt.
“We have already communicated internally within . . . the Ministry of the Environment and with other ministries like the Provincial Emergency Program that we are in a La Nina winter,” he said.

“It is generally very positive for BC because we rely on so much of the snow melt to provide so much of the water supply for fish and for communities to fill up the reservoirs.”