VANCOUVER -- Travellers in British Columbia's southern Interior faced challenging conditions Thursday and driving wasn't recommended as a severe winter storm was forecast to bring 40 centimetres of snow to the region.

An avalanche threat caused the closure of Highway 1 between Revelstoke and Golden until at least 8 p.m. Thursday and no detour was available.

The B.C. government says in a statement that other routes in the same area may be closed while crews work above the highways to eliminate the avalanche threat.

Environment Canada has issued winter storm warnings for most major passes through the Interior, including the Coquihalla Highway from Hope to Merritt where another 20 centimetres of snow was forecast by Friday.

The weather office also warned that an intense Pacific front system will bring hazardous conditions on the Squamish to Whistler section of the Sea-to-Sky Highway as 10 centimetres of snow was expected before turning to rain.

Rainfall warnings were posted for most of Vancouver Island, Metro Vancouver, along Howe Sound, in the Fraser Canyon and the Fraser Valley, with accumulations of up to 50 millimetres of rain in the forecast.