Firefighters kept a nervous eye on gusty winds blowing from the southeast Sunday as they worked to prevent a forest fire in northern Minnesota from advancing on developed areas along Gunflint and Loon Lakes.

Forecasters predicted sustained winds of 10 mph to 15 mph gusting to 25 mph with a 50 percent chance of thunderstorms later in the day along the Gunflint Trail, where a fire that began last weekend has scorched nearly 83 square miles in Minnesota and Ontario combined. The thunderstorms weren't expected to bring enough rain to counterbalance the danger from high winds and lightning.

Cook County Chief Deputy Leif Lunde warned residents at a public meeting Sunday morning that it might be necessary to evacuate the Trail Center area about halfway up the road, including Poplar Lake, if the fire started spreading again.

"Hopefully that will be secure enough where it won't be a problem, but that is the danger," Lunde said.

In an attempt to stop the fire from advancing back on homes and popular resorts on Gunflint Lake and nearby Loon Lake, firefighters intentionally burned an area Saturday evening between the fire and their bulldozer and hand-cut protective lines.

"It went extremely well by all accounts," said Mark Van Every, a spokesman for the firefighting effort. "People have been out there looking this morning and it's looking really good. So we're optimistic that that's going to help us stop that fire from spreading ... It's not a guarantee but we're certainly in a much better position than we were before."

Van Every said firefighters would strive Sunday to prevent the fire from breaking through the lines they've established.

U.S. officials were working closely with Canadian officials who were hoping to conduct burnouts on their side of the border to try to stop the advance of the fire in Ontario, Van Every said. "This is a very high priority fire for them as well," he said.

Officials also reported some progress. The fire was declared 15 percent contained — up from 5 percent most of last week — though there's still no estimate on when it will be fully contained. It grew by only about 700 acres since Saturday.

The areas that burned toward the end of the trail near Sea Gull and Saganaga lakes early last week has cooled considerably, officials said.

Lunde said it might be possible to allow residents along the evacuated upper part of the trail to return to inspect their properties around the middle or end of this week, depending on whether the weather cooperates.

Marilyn Kufahl, manager of Voyageurs Canoe Outfitters, one of several businesses at the end of the trail, said their operation came through the fire in good shape. She said her husband, Don, who's also a volunteer firefighter, went out on Saganaga to escort back some guests who had been canoeing in Canada. She said he was reassured by how the landscape on the big, island-dotted lake remained unspoiled.

"He couldn't even tell anything had happened," she said. "The loons are out, the eagles are flying."

The fire, which began May 5 near Ham Lake, has closed about half of the 57-mile long Gunflint Trail, a dead-end two-lane highway from Grand Marais into the wilderness. The area has been in a prolonged drought.

Officials on Sunday revised their estimate on the number of structures destroyed to 133, including 61 residences and 17 commercial structures. They estimated the value of buildings lost at $3.7 million, and said the costs of fighting the fire were approaching $4 million.