A major change in the weather pattern will occur this weekend and Monday. The change will take place in two steps - the arrival of a Pacific front followed by an Arctic front.
Late on Saturday afternoon a Pacific front will sweep across the North Coast. The snow level will fall rapidly with this system. Rain ahead of the front will turn to snow flurries at higher elevations behind it.
Very cold Arctic air will begin spilling out of the North Coast inlets Monday morning causing significant windchills and probably a few hours of flurries as the front passes. With strong winds accompanying the flurries, visibility may be briefly reduced to zero on the roads in snow and blowing snow. By late Monday the North Coast will be covered by a very dry and chilly Arctic airmass. Sunshine will prevail thereafter.
The Pacific front will cross the South Coast on Sunday night. In the cool moist unstable air behind this system rain showers may turn to snow flurries - even at sea-level. In this scenario, the intensity of the rain is important: the air will cool near heavy rainshowers and this cooling may prompt a local phase-change from rain to snow with local accumulations of a few centimetres.
Late Monday the Arctic air will begin draining out of the South Coast mainland inlets.Residual moisture from the previous front may result in a brief period of snowflurries and local accumulations of a few centimetres. Again, with strong winds accompanying the flurries, local white-out conditions are possible in some preferred locations on the South Coast: Sumas Prairie in the Fraser Valley, Howe Sound and possibly the East Coast of Vancouver Island if the Arctic 'push' is strong enough.
By Tuesday morning the South Coast will be bathed in brilliant sunshine but the windchills will continue as usual in the Fraser Valley Howe Sound and the East Coast of Vancouver Island. Right now it appears the brilliant but cold conditions will persist through next week as another blocking ridge sets up over the Pacific. However an Arctic outbreak often leads to significant snowfall events on the BC coast.
Monitor the latest forecasts and warnings from Environment Canada at www.weatheroffice.gc.ca.
The public is advised to monitor future forecasts and warnings as warnings may be required or extended.
Please monitor the latest forecasts and warnings from Environment Canada at www.weatheroffice.gc.ca
WOCN11 CWVR 291422
Special weather statement
Updated by Environment Canada
At 6:22 AM PST Friday 29 November 2013.
Special weather statement for:
Southern Gulf Islands
East Vancouver Island
West Vancouver Island
Inland Vancouver Island
North Vancouver Island
Central Coast - Coastal Sections
Central Coast - inland sections
North Coast - coastal sections
North Coast - inland sections
Arctic air to reach the BC coast...