The Sheep Fire at the southern edge of Glacier National Park has roughly tripled its size in three days, and following the evacuation of Essex Thursday, officials with the fire team say today will be a critical test for firefighting efforts as powerful winds are forecast to sweep through the region.

The Sheep Fire started Aug. 15 and has burned through an estimated 1,595 acres. The fire is a half-mile west of U.S. 2 and about one mile south of Essex.

During a Friday afternoon briefing at the team’s fire camp at the West Glacier KOA, fire officials made clear that today will be critical test for firefighters as a cold front could bring ridgetop wind gusts up to 45 miles per hour and sustained winds between 25 and 30 mph.

A red flag warning is in effect today from 2 p.m. to midnight across Northwest Montana, meaning a combination of wind, heat and low humidity have the potential to dramatically increase fire activity.

Fire behavior specialist David Greathouse added that record dry fuels on the ground only add to the potential for the fire to spread.

“It’s severe, profound, critical fire conditions out here, sometimes at historical records,” he said, referring to the energy release component, an index used by analysts to measure the dryness of fuels and their potential to add to a fire’s heat.

Multiple drainages in the area will funnel wind through varying terrain, making the fire’s activity and direction all but impossible to predict.

“You’ve got three drainages — Sheep Creek, McDonald Creek and Essex Creek — and what happens is the winds funnel down those drainages and come into the Middle Fork drainage,” Greathouse said after a Thursday night meeting for evacuated Essex residents. “For lack of a better term, when all these winds come together, it just starts swirling.”

However, Tom Clemmons, the team’s meteorologist, said the high pressure system hanging over the region for the past week should give way to more seasonable weather starting Sunday.

“We’re going to receive cooler temperatures and a little better precipitation over the next six to ten days,” Clemmons said.

A 60 percent chance of precipitation is forecast for Sunday, with high temperatures through next week remaining in the mid-60s to low 70s.

On Friday, Greathouse said that if the fire heads into Tank Creek, it could quickly work its way up the drainage and toward Essex. It could also spot over a cliff to the north and begin burning toward the community from the southwest.

“Basically what this fire’s going to want to do is come in the back door toward Essex,” Greathouse said.

Other possibilities include the fire reaching the flatter terrain close the highway, at which point Greathouse said it could build enough intensity for winds to push spot fires across the road and Middle Fork of the Flathead River into Glacier National Park.

“This fire is really kind of setting itself up for big gains,” he said.

Deputy incident commander Mike Goicoechea said five residents have opted to remain behind rather than evacuating.

“We’ll make one more attempt to try to get them to go if it gets real bad and we have to pull out,” he said Friday.

Residents are not allowed to return after leaving the area, since U.S. 2 is closed, although Goicoechea told people Thursday night that they may be allowed back during the cooler evening and early morning hours if fire activity remains modest. Such an action would require the permission of the Flathead County Sheriff’s Office.

For now, crews are focusing on structure protection in the community of Essex, where local fire departments have stationed multiple engines and personnel to assist the management team.

The 332 personnel assigned to the fire are beginning to feel the strain on resources nationwide. The Type II management team arrived 17 days ago, and while normally a fresh team would be brought in to take over management, Rob Gump said none were available.

And since their stay has been extended past two weeks, personnel are required to take a two-day leave on a rotating basis.

“I won’t say we’re a skeleton crew, but we’re a thin crew. So far, we’re dealing with it, but it adds another level of complexity,” said Gump, planning section chief for the firefighting effort.

However, the evacuation came with a thin silver lining, having elevated the priority level for the personnel-strapped management team.

Goicoechea announced Thursday that a Type 1 hotshot crew had finally arrived — a crew the team had been requesting since it took over operations 15 days earlier. A second hotshot crew was scheduled to arrive Friday night.

He also said that Sunday and Monday may provide an opportunity for firefighters to get on the ground to conduct direct suppression efforts and establish a fire line. He added that the pattern in which the Sheep Fire has been burning the heavily timbered forest won’t leave the landscape completely devastated.

“It’s not like this fire is just going to blow on through on a big run and leave a moonscape,” he said. “There’s still going to be some mosaic look and some trees that are OK, [but] whenever it gets an uphill run, it’s going to take out the trees and leave a little pocket of nothing but black.”

U.S. 2 remains closed to traffic through the Middle Fork Corridor, forcing east-west travelers to either take Going-to-the-Sun Road through Glacier Park or the longer southern route through the Swan Valley and Montana 200.

For the time being, some trains are being allowed to traverse the Middle Fork corridor, although operations are limited to nighttime and early morning, when cooler temperatures have been slowing fire activity. However, by Thursday night, fire officials estimated the 1,595-acre fire had spread to within 120 yards of the BNSF Railway tracks.

For obvious reasons, no tankers carrying crude oil are being permitted to traverse the corridor.

Only two Essex residents spent the night at a Red Cross shelter in West Glacier, and they found alternative housing by Friday.

For information on the Sheep Fire, call 406-387-4854 or email 2015thompsonfire@gmail.com.

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