Campers leave Fintry Provincial Park beneath smoke from the Terrace Mountain fire on Wednesday evening. (Betsy Trumpener/CBC)

Another 2,200 residents living along the northwest shore of Lake Okanagan were ordered to leave their homes Thursday as firefighters struggled to bring the Terrace Mountain fire under control.

Forest fire officials say the blaze has already grown to 4,000 hectares and is expected to continue to expand rapidly on Thursday as winds and high temperatures fan the flames through a forest filled with dry fuel.

Environment Canada was forecasting wind gusts up to 80 km/h on Thursday and Friday as thunderstorms pass through the region, raising concerns lightning strikes could spark more forest fires.

The evacuation order applies to the northern sections of Westside Road about 30 kilometres north of West Kelowna, between Caesar's Landing in the south and Killiney Beach in the north.

Officials say the residents must leave the area by travelling north on Westside Road and register in person with Emergency Social Services at the Vernon Recreation Centre, at 3310 37th Ave. in Vernon.

Some refusing to leave

Some residents told CBC News they would not be obeying the evacuation order and would stay at their homes to protect them from the fire and looters, knowing they can leave on their boats if the situation becomes too dangerous.

A new evacuation alert was also issued for the Westshore subdivision to the north of the area under evacuation. To the south of that area, an alert has also been issued for the Cinnebar Creek subdivision to Trader's Cove and Bear Creek Provincial Park. Residents of those areas are warned they must be ready to leave on a moment's notice.

About 175 firefighters and seven helicopters were fighting the fire on Thursday, but its rapid advance was making it too dangerous for ground crews to attack the advancing front, according to forest protection technician Tim Neal.

"We are looking at contingency lines and putting in guards and natural breaks because we can't put the crews in front of the fires," said Neal.

"For one, the fire is moving. For another, we can't put crews in there because there are no escape routes and it's hard for us to get anchor points, so it's a response thing for our crews," he said.

Glenrosa and Rose Valley fires still smouldering

On Wednesday, 13 residents from the nearby Fintry High Farm area were ordered to leave their homes and another 2,200 living along the northwest shore of Lake Okanagan were placed on evacuation alert as the fire spread.

Meanwhile, several thousand residents of West Kelowna remained under an evacuation alert, ready to leave their homes again on a moment's notice, as firefighters continued to put out hotspots from two other fires in the Rose Valley and Glenrosa neighbourhoods.

The fires were fully contained and about 11,000 residents of West Kelowna returned home on Tuesday and Wednesday after the area was evacuated when those fires broke out on Saturday.