O. Be very cautious of nighttime burning. The wind may lessen or stop completely keeping smoke concentrations high in the vicinity of the burn. Burn at night only when you have a definite forecast of optimum conditions. A nighttime smoke patrol is often necessary. P. Anticipate down-drainage smoke flow.
Stable conditions tend to keep smoke near the ground.
In addition, downslope winds generally prevail at night. Thus, smoke will flow down drainage and concentrate in low areas. When relative humidity rises above 80 percent and smoke is present, the formation of fog becomes increasingly likely as moisture condenses on the smoke particles. There seldom are satisfactory solutions to these problems, so they should be avoided entirely whenever possible. Q. Mopup along roads.