Metro Vancouver weather warning: flash floods possible

A wet weather system that dumped heavy rain and snow acrosssouthern B.C. early Wednesday morning is forecast to continue.

Environment Canada is forecasting up to 75 mm of rain could fall in areas such as the North Shore and Fraser Valley by Thursday night.

Some mountain passes, including Allison Pass on Highway 3, saw whiteout conditionsTuesday, and officials with the Ministry of Highways say 27 cm of snow accumulated on Highway 6 through the Monashee Pass overnight.

At lower elevationsin the Fraser Valley, residents have been warned to watch out for flash floods and water pooling on roads, particularly inChilliwack and Abbotsford.

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Motorists are advised to check driving conditions before setting out.

'Volatile week' in Vancouver area

In Metro Vancouver, Environment Canada said that Tuesday's heavy rain would be just the beginning this week.

"An active storm pattern over the Eastern Pacific Ocean will lead to a volatile week of weather ahead," it said.

Between 60 and100 mm of rain is expected over low lying areas this week, with up to 150 mm possible on southwest-facing slopes. And with the heavy rain comes the possibility of flooding.

"With the ground already saturated, river levels are expected to rise in response to the rainfall. Rising temperatures may result in the melting of mid-elevation snow packs which would contribute to the runoff," Environment Canada said.

By Saturday, cold air from the north and strong outflow winds will cause below-normal temperatures and a blustery weekend.

El Nio predicted

Overall, West Coast residents should be expecting above average temperatures this winter according to CBC meteorologist Johanna Wagstaffe.

"NOAA still predicting a 58 per cent chance of an El Nio this winter, which typically means warmer winters for the Pacific Northwest," says Wagstaffe.

"While La Nias do have a correlation with higher snowfall, El Nio doesn'tnecessarilymean less snow, and it doesn't look like it will be a very strong one either."

Across the rest of Canada colder than average temperatures are forecast for the winter ahead.