DULUTH – The Greenwood fire burning in northeastern Minnesota's Superior National Forest doubled in size Monday, stretching to some 30 square miles.
As teams fight the state's largest wildfire, four new smaller fires started Monday within the Boundary Waters Canoe Area Wilderness, and a fire at the edge of Ontario's Quetico Provincial Park moved closer to the Canadian border.
Officials extended the BWCA closure another week, to Sept. 3, as a result.
Mapping of the Greenwood fire via an infrared flight Monday night showed how far the fire spread during its intense run northeast that afternoon, with a preliminary footprint of 19,493 acres. The drought-stricken rural Lake County region didn't get the rain Tuesday that other parts of northeastern Minnesota did, but cloud cover tempered the fire, said Clark McCreedy, public information officer for the interagency team managing the fire.
With such parched vegetation, "what we really need is a belligerent soaker of a rain," he said.
The fire created a pyrocumulus cloud — or fire cloud — visible for miles, with smoke and ash from the fire reported as far as Lutsen, about 30 miles east. On Tuesday, smoke from the fire permeated Duluth for several hours, and residents were advised to keep their windows closed.
Northern Minnesota hasn't seen a pyrocumulus cloud since the 2011 Pagami Creek fire, said Joe Moore, a meteorologist with the National Weather Service in Duluth.
The giant gray clouds are formed by fire-created hot air and smoke and can be dangerous to firefighters, causing gusty winds and lightning. The Weather Service did receive a report of lightning from the Greenwood cloud, Moore said, but couldn't confirm it.
"Based on radar, we guess it got up to 10,000 to 12,000 feet off the ground," he said. "It's incredible to think there is enough energy within that cloud to create the vertical motion for it to grow."
McCreedy said it's still unknown whether any cabins or other structures were lost in the McDougal Lake area, which sat in the path of the fire. He said downed trees made it difficult to access that area to assess damage. Still-standing dead trees were also a hazard.
Pat Prochaska's cabin near the southern lake in the McDougal chain appears to have survived, save for some melted siding, even with a temperature sensor reaching 165 degrees, he said. Four surveillance cameras attached to the house captured the blaze whipping through his 18-acre property Monday afternoon at 3:15 p.m.
"It's pretty amazing," he said. "As far as we know, the house is still standing."
The power was turned off so he's no longer receiving footage. He doesn't have trees within 30 feet of the cabin, and that likely helped, he said.
Fires within the Superior National Forest now number 13, although not all are being actively fought and some are contained. The Petit, Gabi, Rice Bay and Second Creek fires started Monday in the BWCA. All are a half-acre in size. An update from the U.S. Forest Service said one of several Canadian fires near the border moved to the north shore of Iron Lake and Curtain Falls, but hadn't crossed into the BWCA.
Nearly 430 people are now working on the Lake County fire, with more on the way. Two 20-person Type 1 crews — considered the most advanced at fighting fire — are now assisting, and others are on the way, along with more heavy equipment.
However, the fire isn't close to being considered a Type 1 incident yet, and all management teams with that classification are working other fires, McCreedy said. Complex fires like the massive Dixie fire in California with its much larger surrounding population are categorized as Type 1, he said.
Moore said that while the region where the Greenwood fire is burning isn't expected to get much rain in the coming days, it will be cooler, more humid and less windy.
"At least there won't be conditions to spark more extreme fire spread," he said.
Jana Hollingsworth • 218-508-2450