Calmer winds and improved visibility on Sunday helped crews battle the Tatoosh fire that has burned 4,000 hectares near Manning Park in southern B.C. — but it's still spreading unchecked, a provincial official says.

"We still have no containment whatsoever on this fire," Jeff Moore, a fire information officer with the B.C. Ministry of Forests and Range, told CBC News on Sunday.

Since Thursday, the fire has grown to more than 4,000 hectares from 1,000 hectares, or 10 square kilometres. Moore said it was heading north towards Hwy. 3.

An evacuation alert imposed on Tuesday remained in place for people near the provincial park, which is about 150 kilometres east of Vancouver, as well as in the Pasayten River Valley and Eastgate.

However, Moore said the situation was "not alarming at this point and there is no increasing concern for those communities."

On Friday, dry conditions and high winds forced the temporary withdrawal of all crews fighting the blaze.

But Moore said Sunday that increased humidity on the previous day had cleared some of the smoke, allowing the crews to use infrared technology and GPS (Global Positioning System) overnight to map the fire.

"I guess the good news is today there are calmer winds so far and better visibility, although there's increasing smoke volume as the day wears on," Moore said.

The fire started after a lightning strike in Washington state on Aug. 22 and crossed the border over the weekend as a six-kilometre-wide wall of flame.

Not likely to join Border Lake fire

Firefighters had been concerned that the Tatoosh blaze would be joined by the smaller Border Lake fire, which has been burning to the northeast of Manning Park between Keremeos and Princeton.

But officials said they were no longer worried that it's much of a possibility.

As of Saturday, the Border Lake blaze had burned 1,700 hectares after tripling in size from Thursday.

The two fires are now about five kilometres apart.