As thunderstorms swept through Northwest Montana on Friday, wind, lightning and parched conditions created dozens of new fires while fanning the flames of existing ones.

Five separate wildfires are now burning at more than 1,000 acres apiece throughout the region, including the new Trail Creek and Marston fires, burning at 1,300 and 1,200 acres, respectively.

On the Kootenai and Flathead national forests, there were 55 active fires burning Friday night.

Little development has been reported by fire officials on the two major fires burning in Glacier National Park.

The size of the Thompson Fire was downgraded late Friday to 13,202 acres after aircraft used GPS mapping to pin down a more precise estimate of its perimeter in the Nyack Creek drainage of Glacier.

The cause of the Thompson Fire is unknown. It was first reported Sunday afternoon.

The amount of smoke being generated by the fire prompted the Montana Division of Environmental Quality to install temporary air quality sensors in St. Mary and Browning downwind of the state’s biggest wildfire.

Fire team spokesman Greg Dinetto said the fire appeared to gain little size Friday.

“We did have a fairly strong thunderstorm cell come through about an hour or so ago, and it did put some rain and lightning down, but we didn’t get a lot of wind,” Dinetto said Friday evening. “From what we can tell, [the fire] did not cross the Divide.”

If the weather permits today, the management team plans to begin putting limited ground crews into the fire area.

One team of 10 firefighters will work in the Nyack drainage suppressing hot spots in avalanche chutes. The other 10-member team will land at Cut Bank Pass and search out hotspots with the potential to spread into that drainage.

Two water-dropping helicopters are also deployed at the fire, and Dinetto said that little to no more resources are expected at this time.

“With as many fires as are happening, both in our area and nationally, resources are in high demand. Unless we have some very significant resources or values at risk, then likely we’re not going to see any additional crews.”

A total 104 personnel are listed as working on the fire, a small fraction of the number sent last month to Glacier Park’s Reynolds Creek Fire, which topped out at 4,311 acres.

That fire is still being mopped up by a Type III fire team, according to the last available report.

On Friday, a third wildfire popped up in the park at Goat Haunt.

Park spokeswoman Denise Germann said firefighters from the adjacent Waterton Lakes National Park were responding to the lightning-started fire with water drops from helicopters.

The Goat Haunt Fire was clearly visible Friday on one of Glacier Park’s webcams (www.nps.gov/glac/learn/photosmultimedia/webcams.htm).

Across Northwest Montana, 44 new wildfires had been reported on Friday by press time, and firefighters continued to chase smoke reports and find new fires burning throughout the night.

Fifteen new wildfires had been reported by Friday evening by Kalispell fire dispatch, which handles incidents in the valley, Glacier National Park and the lands in and around the Flathead National Forest.

Spokeswoman Ema Braunberger estimated 20 active fires were still burning throughout the 2.5 million-acre forest.

The Bear Creek Fire southwest of Spotted Bear Ranger Station slowed down after hitting 151 acres Friday. It began after a lightning strike on Wednesday and tore through 135 acres in one day.

Pushed by Friday’s winds, the Three Sisters Fire spilled over the Divide into the Lewis and Clark National Forest after remaining quiet since it slowed down at about 44 acres the previous week. No estimate of the fire’s new size was available, however.

In the Swan Valley, the Richmond Complex grew to an estimated 400 acres on Friday and the plume was clearly visible from Montana 83.

The Sucker Creek Fire, which had burned through 1,500 acres near Lincoln by Friday night, prompted a mandatory evacuation order for the Alice Creek area.

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.