Another rainstorm is drenching B.C.'s South Coast, dumping up to a full month's worth of rain and triggering flood and high water warnings.

Up to 150 mm of rain – or about six inches – will fall on parts of Vancouver Island, Vancouver's North Shore, Howe Sound and the Fraser Valley, while rising freezing levels will melt more snow, according to Environment Canada.

The average rainfall amount for January in these areas is usually about 140 mm.

A flood watch has been issued for several rivers on the island – including the Cowichan, Chemainus, Nanaimo, Englishman and Tsolum – with a warning that flooding could occur Friday when rising rivers meet a high tide.

A high streamflow advisory has been issued for Metro Vancouver and the Fraser Valley where rivers and steams are expected to rise quickly in some areas.

Winds whipping up

The stormfront is also causing strong winds. Southeast winds of 50 to 70 km/h have developed over sections of Greater Victoria, West Vancouver Island and Southern Gulf Islands, Environment Canada said.

Further north, southeast winds of 80 to 100 km/h have developed over the central coast. Winds will abate over the central coast Thursday night and Friday morning over the South Coast.

Unseasonably warm weather combined with the heavy rainfall has already forced the closure of Cypress Mountain Resort, Vancouver's Olympic ski hill, one month before several 2010 Winter Olympics begin.

Alpine ski runs at Cypress, on the North Shore of Metro Vancouver, will remain closed to the public in order to preserve the snow remaining on the slopes. With files from The Canadian Press