- Associated Press - Monday, July 9, 2012

HELENA, Mont. — Firefighters expected to have the state’s largest wildfire contained Monday, but the victory could be short-lived with lightning, heat and 50 mph wind gusts forecast to sweep into central and southeastern Montana later this week.

All the fire lines holding back a complex of five wildfires burning in southeastern Montana held overnight, information officer Terina Mullen said Monday in a statement. The largest of the five, the 250,000-acre Ash Creek fire, was 90 percent contained Monday morning, with full containment expected later in the day.

“There are no smokes near the fire lines, and rehab and patrol of fire lines is the primary focus. Demobilization of resources is in full swing today,” Mullen said.

The fire has burned at least 16 homes and 22 other structures.

A high-pressure system moving into the region is expected to raise the temperature and drop the humidity. The National Weather Service issued notice Monday that critical fire weather conditions are expected to arrive on Tuesday afternoon, with temperatures up to 100 degrees, relative humidity at 10 to 15 percent and 50 mph wind gusts that have the potential to cause fires to spread rapidly.

In addition, scattered thunderstorms are expected to bring lightning that could threaten more fire starts, according to the weather service.

A Sunday night infrared flight spotted three possible new fires in southeastern Montana, and fire officials planned a flyover Monday to better gauge their size as Bureau of Land Management crews headed to the area, Mullen said.

Crews were mopping up one of the most active fires in the region, the 62,000-acre Taylor Creek fire about 12 miles southeast of Fort Howes, and it was 65 percent contained as of Monday morning.

The three other fires that make up the Southeast Montana Complex were between 95 percent and 100 percent contained. More than 920 crew members were on the scene.

In western Montana, cloud cover slowed the spread of a 60-acre wildfire burning in the Bitterroot Mountains on the Montana-Idaho border. The Missoulian reports the Chrandal Creek fire has been burning for about two weeks but escaped detection until a rapid spread on Saturday.

Firefighters said the improved weather Sunday helped, but they are also concerned by the hot, dry conditions forecast for the week.

In southwestern Montana, Mammoth residents were allowed back to their homes Monday for the first time since late last month after officials said the Pony fire southeast of Whitehall was contained.

That fire has burned more than 5,100 acres and its cause was under investigation.