CFC Meteorological Briefing & Interpretation 5 — Questions and Answers
Question 1: A weather briefing describes a rapidly deepening low-pressure system with the pressure falling 6 mb in 3 hours. A flight communicator should recognize this as:
- An explosive cyclogenesis ('bomb'), indicating rapidly deteriorating weather (Correct answer)
- A standard frontal passage with predictable timing
- A high-pressure ridging event bringing clear skies
- A thermal low with minimal moisture and stable conditions
Correct answer: An explosive cyclogenesis ('bomb'), indicating rapidly deteriorating weather
A pressure drop of 1 mb/hour or more over 24 hours (24 mb/day) qualifies as explosive cyclogenesis, signaling rapidly worsening conditions.
Question 2: A warm front passage is typically associated with which sequence of weather changes?
- Gradual improvement from stratus/drizzle to warmer, clearer conditions as the front passes (Correct answer)
- Rapid clearing followed by cold temperatures and gusty winds
- Isolated thunderstorms followed by an abrupt drop in dew point
- Heavy snow immediately followed by fog and freezing rain
Correct answer: Gradual improvement from stratus/drizzle to warmer, clearer conditions as the front passes
Warm fronts bring prolonged low ceilings, drizzle, and fog ahead of the front, with conditions improving gradually after passage.
Question 3: When interpreting a weather depiction chart, what does a station model with a circle entirely filled in (blackened) represent?
- Overcast sky cover at that reporting station (Correct answer)
- Thunderstorm activity at the station
- Freezing precipitation
- Unknown or missing sky cover
Correct answer: Overcast sky cover at that reporting station
On a weather depiction chart, a completely filled circle indicates an overcast sky (8/8 coverage).
Question 4: A flight communicator notes that the temperature/dew point spread in a METAR is 2°C. This spread is significant because it suggests:
- Conditions are close to saturation, increasing likelihood of fog or low clouds (Correct answer)
- The air is very dry with minimal cloud formation risk
- Freezing precipitation is imminent at the surface
- Winds will increase as atmospheric instability develops
Correct answer: Conditions are close to saturation, increasing likelihood of fog or low clouds
A small temperature/dew point spread (2°C or less) indicates near-saturation; fog or low stratus is likely, especially at night or at dawn.
Question 5: An occluded front forms when:
- A faster-moving cold front catches up to and lifts a warm front (Correct answer)
- Two cold air masses converge and stall
- A warm air mass overruns a stationary front
- A tropical airmass moves poleward and encounters cold air
Correct answer: A faster-moving cold front catches up to and lifts a warm front
Occlusion occurs when the cold front overtakes the warm front, lifting the warm air mass off the surface.
Question 6: Which type of weather briefing should a flight communicator recommend when a pilot is already familiar with general conditions but needs a quick update on hazards?
- Abbreviated briefing (Correct answer)
- Outlook briefing
- Standard briefing
- NOTAM-only briefing
Correct answer: Abbreviated briefing
An abbreviated briefing supplements a pilot's existing weather knowledge with specific updates on current hazards or changing conditions.
Question 7: A prognostic chart valid 24 hours from now shows a trough of low pressure aligned NNE–SSW across the central US. A flight communicator should anticipate this trough will likely bring:
- Scattered showers and possible thunderstorms along and ahead of the trough axis (Correct answer)
- Clear and calm conditions directly under the trough
- A temperature inversion and widespread fog formation
- Rapid improvement in visibility and ceilings as the trough passes
Correct answer: Scattered showers and possible thunderstorms along and ahead of the trough axis
Troughs of low pressure trigger convergence and uplift, increasing the likelihood of convective activity and precipitation along and ahead of the trough.
CFC Meteorological Briefing & Interpretation 5
A weather briefing describes a rapidly deepening low-pressure system with the pressure falling 6 mb in 3 hours.
A flight communicator should recognize this as: