High streamflow advisory issued with hot weekend forecast

Photo: File photo - Castanet staff

Temperatures are forecast to spike to the mid-to-high 20s this weekend, bringing a risk of rising waters in creeks and rivers across the Interior.

The BC River Forecast Centre issued a high-streamflow advisory Wednesday afternoon, warning of the possibility of “extremely high flows” and possible flooding in the Okanagan and Thompson regions, along with areas as far north as Prince George.

A strong upper ridge is expected to bring toasty temperatures to B.C. beginning Thursday. In Kelowna, the mercury is forecast to hit a high of 27 C on Saturday, followed by 26 C Sunday, while Kamloops could see 28 C Saturday and 26 C Sunday.

The River Forecast Centre says mid-elevation snowpacks (between 900 and 1,500 metres) have “ripened,” meaning the snowpacks have already warmed up enough to yield meltwater. As a result, these snowpacks are “expected to respond with sharp rises in snowmelt rates over the weekend.”

The River Forecast Centre says the warming at higher elevations is expected to be absorbed into snow ripening, and will cause less meltwater.

“River responses will be variable across the region, with watersheds containing a high degree of mid-elevation terrain expected to have the most significant increase in river levels over the weekend,” the River Forecast Centre says.

Locally, waterways that could see impacts include Salmon River near Falkland and Salmon Arm, Whiteman Creek on the west side of Okanagan Lake and Inkaneep Creek between Oliver and Osoyoos, along with Cache Creek, Bonaparte River and Guichon Creek in the Thompson region.

Additionally, the River Forecast Centre says “similar creeks and rivers across the region” could also see impacts.

The advisory warns people to stay clear of fast-flowing rivers and potentially unstable riverbanks and avoid fishing, swimming, boating or hiking near high streamflow rivers or streams.