CPFM Weather & Atmospheric Conditions Flashcards

What term describes the depth of the atmospheric layer where vertical mixing occurs, directly affecting smoke dispersal?

Answer: Mixing height

Mixing height is the vertical extent of the layer in which atmospheric mixing occurs, determining how high smoke will rise and disperse.

Which fire weather forecast product provides site-specific meteorological data tailored to a single burn unit?

Answer: Spot weather forecast

A spot weather forecast is issued by the National Weather Service for a specific location, time, and elevation to support a planned prescribed burn operation.

What does ERC stand for in fire weather forecasting?

Answer: Energy Release Component

Energy Release Component (ERC) is a fire weather index that estimates available energy in the upper fuel layer, reflecting cumulative drying and fire intensity potential.

What does a low Ventilation Index indicate for a planned prescribed burn?

Answer: Poor smoke dispersal conditions

A low Ventilation Index means limited mixing and wind transport, which can cause smoke to accumulate near the ground and create hazardous air quality.

Which wind component most directly determines fire spread direction during a prescribed burn?

Answer: Surface winds

Surface winds are in direct contact with surface fuels and flames, making them the primary factor controlling fire spread direction and rate.

How does a Fire Weather Watch differ from a Red Flag Warning?

Answer: A watch is less urgent — critical conditions possible in 24–72 hours

A Fire Weather Watch means critical fire weather conditions are possible within 24–72 hours, while a Red Flag Warning means those conditions are imminent or already occurring.