CPFM CPFM Weather & Atmospheric Conditions 2 — Questions and Answers
Question 1: What term describes the depth of the atmospheric layer where vertical mixing occurs, directly affecting smoke dispersal?
- Convective ceiling
- Mixing height (Correct answer)
- Thermal boundary
- Smoke transport altitude
Correct 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.
Question 2: Which fire weather forecast product provides site-specific meteorological data tailored to a single burn unit?
- Standard weather forecast
- Red Flag Warning
- Spot weather forecast (Correct answer)
- Marine weather advisory
Correct 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.
Question 3: What does ERC stand for in fire weather forecasting?
- Energy Release Component (Correct answer)
- Expected Rate of Combustion
- Extreme Risk Category
- Environmental Risk Calculator
Correct 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.
Question 4: What does a low Ventilation Index indicate for a planned prescribed burn?
- Excellent smoke dispersal conditions
- Poor smoke dispersal conditions (Correct answer)
- High expected fire intensity
- Low available fuel moisture
Correct 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.
Question 5: Which wind component most directly determines fire spread direction during a prescribed burn?
- Jet stream winds
- Surface winds (Correct answer)
- Upper-level winds
- Geostrophic winds
Correct 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.
Question 6: How does a Fire Weather Watch differ from a Red Flag Warning?
- A watch is less urgent — critical conditions possible in 24–72 hours (Correct answer)
- A watch is more urgent than a warning
- A watch applies only to nighttime hours
- A watch is issued only for forested regions
Correct 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.
CPFM CPFM Weather & Atmospheric Conditions 2
What term describes the depth of the atmospheric layer where vertical mixing occurs, directly affecting smoke dispersal?