The respite from dense smoke in the Rogue Valley may give way to more haze from regional fires for the next three days.

Smoke from Chetco Bar, Miller Complex, and High Cascades Complex fires could thicken above the Rogue Valley, weather forecasters say, before cooler air and northwest winds arrive late in the week.

A one-two rain and wind punch last last week chased much of the smoke from the valley, leading the National Weather Service's Medford bureau to tweet it measured 10-mile visibility at the airport for the first time since Aug. 31.

"The rain rinse the particulates out of the air and then there was a strong push of marine air from the northwest as a cold front came through," said Dan Weyand, a meteorologist with the National Weather Service in Medford. "The stronger winds at the ridge-tope level pushed the smoke out of the valley."

By Saturday, Medford's air quality index reading dropped to 90, improving from hazardous earlier in the week to moderate.

"We had such an improvement in relative humidity that it reduced the strength of the fires, and they were producing less smoke," Weygand said.

Nonetheless, the warming trend with three straight days in the 90s through Tuesday may trigger more fire activity. On Sunday, visibility was 6 miles and it may fall to 3 miles the next couple of days.

Heading into the middle of the week, forecasters anticipate a system delivering moisture from the south. It will spur a cooling trend, but could spark thunderstorms, predominantly in the south Siskiyous and east of the Cascades.

"The cooling will be noticeable by the end of the week," Weygand said. "Early next week, we might see some rain."

The Miller Complex grew to 34,088 acres over the weekend, and remains 33 percent contained.

The Joe Bar area, located in California near the north edge of the Abney Fire, remains under an evacuation warning.

Firefighters took advantage of higher humidity, lower temperatures and moisture reduced fire behavior to extending containment lines on the Creedence, Bigelow and Burnt Peak fires. Crews on the Abney fire will continue to build, improve and secure containment lines to the east, north and northwest of the Abney fire.

"We're seeing a lot more black line (showing containment) on our maps and that's what everybody wants to see," Miller Complex public information officer Charissa Reid said. "There's still going to be activity in the interior of the fire. But we've got a couple of things working in our favor in the Palmer Creek and Applegate Road areas, including the inversion lifting. We're working on a long-term plan, so it requires patience for it to come to fruition.

The 184,208-acre Chetco Bar fire turns two months old, but remains just 5 percent contained.

The fire remains about 10 miles from residential areas around Cave Junction. Higher temperatures are expected to kick up fire activity today.

About 40 miles of old Biscuit Fire bulldozer lines were reopened and completed on the east end of the fire, and new bulldozer lines have been completed since Saturday.

"The area around Mount Emily is stationary, giving opportunities for firefighters to get lines in," Chetco Bar fire spokesman Jon Koeespies said.

— Reach reporter Greg Stiles at 541-776-4463 or business@mailtribune.com. Follow him on Twitter at www.twitter.com/GregMTBusiness, and on Facebook at www.facebook.com/greg.stiles.31.