Rainfall warnings issued on South Coast as atmospheric river approaches

As much as 100 millimetres of rain is expected to fall on parts of the Lower Mainland this weekend, as the South Coast sees its second atmospheric river since Thursday.

Environment and Climate Change Canada issued a rainfall warning for Metro Vancouver, Howe Sound and the Fraser Valley Saturday morning, saying periods of rain "will gradually intensify" overnight and continue through Sunday evening.

In most of the region, rainfall totals are expected to be in the 50-to-70-millimetre range, but the North Shore mountains and the Howe Sound region should expect 80 to 100 millimetres.

Rainfall warnings have also been issued for B.C.'s Central and North Coast regions, as well as the coasts of Vancouver Island.

HIGH WINDS EXPECTED

Environment Canada is also warning of high winds, with gusts near 70 km/h forecast for the Boundary Bay area, and sustained winds of 50 km/h possible elsewhere.

The City of Vancouver told CTV News it has increased staffing and availability of equipment to respond to potential localized pooling of water and blocked catch basins.

BC Hydro said it is also ramping up staffing.

"We have brought in contractor crews that are on standby," said Susie Rieder, a spokesperson for BC Hydro.

"This storm system looks like it's going to be quite a serious one.”

The strong wind could mean the potential for downed power lines.

"A downed line is an emergency," Rieder said. "Please stay back and call 911 if you see one ... Stay back 10 metres. That’s about the length of a bus.”

She said Hydro crews had been preparing for a storm such as this one even before meteorologists forecaste the weekend's storm.

“We’re going around looking to identify weakened or dead trees and removing them to mitigate the chance that there could be power outages because of trees or branches falling in to our lines,” Rieder said.

Meanwhile, BC Ferries has cancelled sailings between Bella Bella, Ocean Falls and Bella Coola for Sunday. Those sailings have been rescheduled to the following Wednesday.

"In consultation with the senior marine meteorologist with Environment Canada, it was determined that the wind would exceed the Northern SeaWolf's parameters, making sailing unsafe,” said Karen Johnston, the executive director of communications and engagement for BC Ferries.

Johnston suggests passengers of other sailings check online beforehand, as adverse weather conditions can always change schedules.

FLOOD PREP INFORMED BY LAST YEAR

"Heavy rain will ease Sunday night with the passage of the system," Environment Canada said in its warning.

"Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible." 

In Abbotsford – where some residents of the Sumas Prairie neighbourhood saw their homes underwater for weeks during last year's catastrophic flooding – the city issued a warning to residents on Friday. 

While this weekend's weather is not expected to be as severe as the storms that caused last year's flooding, Abbotsford is once again making sandbags and sand available at its public works yard on King Road.

Mayor Henry Braun told CTV News he's feeling optimistic heading to the weekend.

"Our dikes are half a meter higher than pre-flood last year, we have strengthened it and all the temporary repairs have been made,” Braun said.

He noted that last year's devastating flood was made worse because of a massive amount of melting snow.

Though the community isn’t dealing with snow right now, he said the fall season can bring on another dangerous issue instead.

“Please check your storm drains and catch basins on the streets, because the leaves are coming down and if they’re plugged, the water is just going to head downhill and in to the first driveway,” Braun said. 

The B.C. River Forecast Centre has issued high streamflow advisories for the entirety of the B.C. coast, including Vancouver Island and Haida Gwaii. 

A high streamflow advisory means that "river levels are rising or expected to rise rapidly, but that no major flooding is expected," according to the forecast centre.

Minor flooding in low-lying areas is possible during a high streamflow advisory.