Officials have issued flood watches and high streamflow advisories for parts of northern B.C. and the Interior as rains and thunderstorms pass through the province.

Environment Canada has issued a special weather statement warning of up to 40 mm of rain and embedded thunderstorms in the southern Interior through Saturday afternoon.

Flood watches — which mean river levels are rising and could go over the top of banks — have been maintained for the Upper Columbia and East Kootenay regions in the east, as well as a portion of central B.C.

Meanwhile, high streamflow advisories, which indicate that river levels are rising, are in place for regions stretching from the Peace in northern B.C. to the Similkameen in the south.

"We're watching this pretty broad area, because it is a large precipitation event coming in, and it's coming from this unusual direction," said Natasha Cowie, a hydrologist with the B.C. River Forecast Centre.

"It's a bit of an unusual storm because it's coming in from the eastern side, hitting the Rockies," she added. "So Alberta is probably going to get quite wet, and then some of that rain is going to make it on over to us as well."

It's hard to predict the exact areas where flooding could occur, as forecasters don't know exactly how much rain will fall, and how the ground will absorb it, Cowie said.

"Use a lot of caution around rivers and streams, especially if you're out with children or with pets," she said. "Just be aware that flows are probably going to be pretty high. There could be a lot of debris in the water."

Environment Canada said showers will be widespread Saturday in the southern Interior, and thunderstorms will further increase precipitation rates.

A severe thunderstorm watch was issued for the South Thompson region, including Kamloops, just before 11 a.m. PT.

Jane Cook, a fire information officer with the B.C. Wildfire Service, said the rainfall was good news and is helping bring down fire danger in the province.

She added, however, that the thunderstorms in the southern half of the province could lead to wind gusts of up to 70 km/h.

"Although this precipitation can bring a reprieve from that elevated fire activity, [in] regions that are receiving heavy rainfall, particularly those that have been experiencing prolonged drought, it brings the potential for moderate flood hazard to emerge," she said.

Cook said that firefighting personnel were on standby in case they needed to assist with flood support this weekend.