As cooler weather comes into town, The Coconino National Forest will be performing three hand pile burns and one machine pile burn beginning Monday. All operations are due to leftover material from previous treatments both north and south of Flagstaff and reduce the potential for a catastrophic fire. The Hotshot Ranch Piles project will burn northwest of Flagstaff just east of Highway 180 near Valle, and the Mountainaire Pile project will burn east of Interstate-17 at the Mountainaire exit. The Narrows Hand Piles will burn even more east than the Mountainaire burn, just off Forest Road Three. The machine pile burn will be at Willard Pit, south of Flagstaff, just west of the I-17. Officials say the smoke impact from the Willard Pit burn will be high during the ignition period which will last about three weeks, but the smoke impact from the other burns should be light and short. Evening smoke may settle close to Snowbowl Road and the Mountainaire exit on I-17. Ignitions are planned to begin on Monday, and are expected to be finished by Friday.