Weather Observation Flashcards
7 cards from real S-130 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Weather Observation flashcards as text
What is a 'Red Flag Warning' and what conditions typically trigger it?
Answer: A National Weather Service alert for critical fire weather combining low humidity, high winds, and dry fuels
Red Flag Warnings are issued by the National Weather Service when a combination of low relative humidity, strong winds, and dry fuels create extreme fire danger.
Which topographic feature causes a 'saddle' or 'notch' effect that dramatically accelerates wind speed through it?
Answer: A col or gap between two peaks
Cols, saddles, and notches between terrain features act as funnels that compress and accelerate wind, creating locally extreme and dangerous conditions for firefighters.
A fire weather forecast states 'winds become erratic after 1400.' What should incident commanders do with this information?
Answer: Ensure all crews are in safe zones or have escape routes identified before 1400
Predicted erratic winds are a critical trigger: all crews must be in defensible positions with clear escape routes before the forecasted time.
What is meant by 'fuel moisture recovery' during nighttime hours?
Answer: The reabsorption of atmospheric moisture by dead fuels as temperature drops and humidity rises at night
Overnight, dropping temperatures and rising relative humidity allow dead fine fuels to absorb moisture from the air, temporarily reducing their flammability.
What does the acronym 'RAWS' stand for in the context of fire weather data collection?
Answer: Remote Automated Weather Station
RAWS (Remote Automated Weather Stations) are unmanned weather monitoring stations that continuously collect and transmit fire-weather data from remote locations.
How does a Foehn wind (or its North American equivalent, the Chinook) affect fire danger?
Answer: It is a warm, dry downslope wind that rapidly dries fuels and increases fire danger
Foehn/Chinook winds descend and compress on the lee side of mountains, warming and drying dramatically, which can critically lower fuel moisture and drive extreme fire behavior.
When observing smoke column behavior, what does a smoke column that leans and then 'mushrooms' at a low level indicate?
Answer: An inversion layer capping the convection at a low altitude, indicating atmospheric stability
Smoke that rises then spreads laterally at a low level is hitting a temperature inversion, indicating atmospheric stability and reduced convective column strength.