B.C. watches flood risk as rains ease, but heat has potential to melt snowpack

VANCOUVER – Sunshine may have replaced rainy conditions across much of British Columbia, but the warm spell may not offer respite from risks of flooding.

Dave Campbell, head of the River Forecast Centre, said water levels are being watched closely as temperatures rise into the low-to-mid 30s.

"We do anticipate that this is certainly going to drive up snow melt rates across the province," he told a news conference Friday.

British Columbia is in the advanced stages of the snowmelt freshet season, he said.

"We're seeing now that the high elevation snowpack has advanced in terms of its melt," Campbell said.

"We're about half to three quarters of the way through the upper elevation snowpack, and we are seeing that a lot or most of the mid-elevation sites are now snow free."

Localized flooding has already been reported along some areas of Shuswap Lake, but officials predict levels will peak this weekend, avoiding severe overflow, while the City of Abbotsford says the Lower Fraser River will crest within six to nine days.

The city's website says levels will stay high for several days once the peak is reached and "residents living in areas along the Matsqui Dyke and Glen Valley Areas may experience pooling of water or seepage."

An evacuation alert issued two weeks ago by the District of Kent, just east of Abbotsford, is still in effect for properties at the mouth of the Harrison River where it joins the Fraser River.

But drier conditions have allowed the District of Sicamous to lift the latest evacuation alert for 27 properties in a mobile home park at the base of a slope considered extremely likely to slide sometime in the next two years.

Armel Castellan, a meteorologist with Environment Canada, said high temperatures will cocoon most of the south coast, the southwest and central Interior regions all the way up to Dease Lake through the weekend into Monday.

"We're talking about five to 10 degrees above seasonal daytime high temperatures," he said. "This is not record-breaking like we saw during the heat dome of 2021."

Tuesday will see an end to the heat, with rain forecast for south of the Yellowhead Highway between Prince Rupert and Prince George, Castellan said.

"This is not a textbook event with dry cold fronts and lightning reaching dry ground the same way that we can sometimes see in the middle of summer, but it will bring precipitation again on Tuesday and it could be quite heavy."

Campbell said the centre is also keeping a close eye on the forecast for unsettled weather and thunderstorms, which could bring additional flood risks.

Several areas are vulnerable to flooding from a combination of rain and run-off, but most of the province will “turn the corner” and go past the critical period of snowmelt over the next few days, he said.

"We're not there yet," Campbell said. "I do anticipate that as we come into the latter part next week that those risks related to the snowmelt component of flooding will start to taper off, but we have to kind of get ourselves through this weather over the coming weeks."

This report by The Canadian Press was first published June 24, 2022.