Smoke: Fire Weather Forecast
Several elements from the National Weather Service’s Local Fire Weather Forecast can help predict smoke dispersal. Mixing height is the distance to which vigorous mixing of the air occurs due to convection. The mixing height can be capped under stable conditions by an inversion layer, prohibiting the smoke from rising any higher. Transport winds are the upper-level winds that move smoke from the burn area. Ventilation rate or vent rate is a measure of how well the smoke will be moved from the area by transport winds expressed in square meters per second or knot-feet. The following are some guidelines for good smoke dispersal:
- Mixing height: 1,700-6,500 ft. above ground
- Transport windspeed: 9-20 mph
- Ventilation rate: greater than 6,000 m2/second
Courtesy of NWS