Some rain relief for southwestern B.C. before deluge resumes

Heavy rain is expected to return across B.C.'s most densely populated region Monday and continue through Thursday as the latest atmospheric river of the season approaches.

Since Saturday, an atmospheric river — a narrow band of heavy precipitation moving eastward from the Pacific — has resulted in 50 to 200 millimetres of rain falling from Vancouver Island to the Fraser Valley, according to the province's River Forecast Centre.

Environment Canada has issued a rainfall warning for Howe Sound, up to Squamish and Whistler. It said up to 100 millimetres of rain could fall in the region by Tuesday morning.

In the Vancouver and Victoria areas, morning rain on Monday is expected to transition to cloudy conditions, with temperatures as high as 14 C, the forecaster said. Periods of rain are expected to begin again Monday evening and last until Thursday.

Flood warnings downgraded

On Monday, the River Forecast Centre downgraded flood warnings for rivers around Abbotsford and on Vancouver Island to flood watches.

But it said another strong weather system is expected for the region Monday into Tuesday, with the heaviest rainfall forecast over western Vancouver Island and the Coast Mountains.

"Temperatures are expected to warm during this period, and snowmelt at lower and mid-elevations will provide additional runoff to rivers," it said. "Rivers have risen and are expected to experience periods of high flows into next week."

A flood watch is the second level on the provincial forecast centre's three-tiered warning system. It means that river levels are rising, and flooding in areas adjacent to riverbanks may occur.

The latest bulletin from the River Forecast Centre said although high water flows for the Nooksack River in Washington state, south of Abbotsford, have reached a local flood stage, levels began to recede Sunday night.