Thursday, July 30, 2009

'Like shoving an elephant'

That means the weak frontal systems that normally spin in from the open Pacific Ocean onto the West Coast during the summer are now being deflected far up to Alaska and Canada's north.

"It's so broad, so big, it's almost like shoving an elephant out of the way," said Martin.

Just when the elephantine heat wave will move on is impossible to predict, she said.

That's because it will likely require a series of frontal systems to gradually break down the high-pressure ridge starting in the upper atmosphere, and there are no such systems strong enough to do that in the forecast.

Any long-term weather forecasts that show the temperature dropping in four days, even those from Environment Canada, are somewhat misleading, said Martin.

"The models keep saying it's coming to an end in four days. There may be a slight reprieve through the weekend, but after that, it will likely to heat up again," she said.

The problem with long-term forecasts is that they are based on statistical models that assume the temperature will return to the season average after four days. But under this massive high-pressure ridge, there's nothing pointing to that happening anytime soon, she said.

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