The advisory covers the the Okanagan, Similkameen, Boundary, Kootenay and Thompson regions, and warns heat and rapid snowmelt mean rivers such as the Tulameen, Kettle and Salmon, and the traditionally flood-prone Mission Creek could surge.
River forecaster Dave Campbell says some smaller interior rivers such as the Salmo, West Kettle and Moyie are running high and could go higher as more hot and dry weather is expected over the weekend.
"We're expecting to see potential creeping-up of temperatures in the next few days and, with that, increased snow melt and increased river levels," he said.
Campbell said there could be some localized flooding in low-lying areas, and urges people to use caution around rivers and streams, which may be flowing faster than usual.
Fast-moving water is now rushing through an abandoned property in the community of Joe Rich, east of Kelowna.
John Collinson, president of the Joe Rich Community Association, says residents are concerned that parts of the washed-out property could damage a nearby bridge on Highway 33.
"Everybody is concerned about drinking water," Collinson said. "They're also concerned about being able to get through on the highway. It's the only way they can get into town."
The Ministry of Transportation was on site Thursday, placing boulders near the water's edge to prevent further road damage.
On Tuesday a 60-year-old woman was swept away in the Willow River, about 30 kilometres east of Prince George.
- Willow River search called off due to unsafe conditions
And on Wednesday afternoon, Cache Creek burst its banks about two kilometres outside the village of the same name.