The north slope of the Atna Bay fire as seen from Morice Lake, east of Kitimat, B.C., this weekend. (Contributed by: Erik Jensen)

B.C. firefighters are on high alert Monday as parts of the province are on a severe thunderstorm watch and many areas are at high to extreme fire risk.

For the first time this fire season, crews are on red alert, ready on base and prepared to load up helicopters as soon as a call comes in, says Penticton forest protection officer Jim Mottishaw.

"The fine fuels are such that any lightning strike is probably going to start a fire if it hits the ground," said Mottishaw. "We're not waiting if there's going to be a fire, we know something will start and it's a quick response."

An extreme thunderstorm watch is in effect for the North Thompson, South Thompson, Shuswap and Okanagan Valley.

"We have a system moving in a loft that's going to destabilize the atmosphere," explains Environment Canada meteorologist Doug Lundquist.

"We already saw some kind of bumpy cloud yesterday, late in the day, so there's some instability there that could set off thunderstorms today, so we have a thunderstorm watch for much of the southwest Interior."

50 new fires started in B.C. over the weekend

More than 50 new forest fires were sparked over the weekend, 15 of which were in the Kamloops fire zone, said fire information officer Michaela Swan.

"The largest was about 10 hectares in size, and that was located about 35 kilometres west of Summerland," said Swan Monday morning.

"We do actually have a new fire this morning, the air tankers will be launching here shortly out of Penticton, right near the Elkhart Lodge over the Coquihalla Connector, and that fire is estimated at about two hectares in size," she said.

Fire closes 40,000 wilderness hectares in northeastern B.C.

In the far northwest, crews are tackling a blaze at Good Hope Lake near Boya Park, east of the Dease River.

A wildfire in northeastern B.C. has forced the closure of 40,000 hectares of wilderness.

The Eskal fire is burning 60 kilometers southeast of Fort Nelson, and has grown to 35 square kilometres since being started by a lightning strike almost two weeks ago.

Burns Lake and Houston are both under a wildfire smoke advisory, due to smoke from the Atna Lake fire in nearby Morice Lake Provincial Park.