CPL Meteorology and Weather Interpretation 1 — Questions and Answers
Question 1: What causes wind to flow around high and low pressure systems?
- Cloud movement
- Jet stream
- Pressure gradient and Coriolis effect (Correct answer)
- Temperature inversion
Correct answer: Pressure gradient and Coriolis effect
Wind flows from areas of high pressure to areas of low pressure due to the pressure gradient force. However, the Coriolis effect, caused by the Earth's rotation, deflects this wind. In the Northern Hemisphere, it deflects winds to the right, leading to the characteristic clockwise flow around high-pressure systems and counter-clockwise flow around low-pressure systems.
Question 2: What does a METAR report provide to pilots?
- Forecast for next week
- Runway availability
- Current weather conditions (Correct answer)
- Passenger manifest
Correct answer: Current weather conditions
A METAR (Meteorological Aerodrome Report) is a routine aviation weather report that provides a snapshot of the current weather conditions at an airport. It includes vital information such as wind speed and direction, visibility, sky conditions, temperature, dew point, and altimeter setting. Pilots use METARs for pre-flight planning and to assess real-time conditions.
Question 3: Which weather phenomenon is most hazardous during landing?
- Drizzle
- Humidity
- Wind shear (Correct answer)
- Fog
Correct answer: Wind shear
Wind shear, a sudden and drastic change in wind speed and/or direction over a short distance, is particularly hazardous during landing. A sudden decrease in headwind or increase in tailwind due to wind shear can cause a rapid loss of airspeed and lift, potentially leading to a dangerous sink rate, a hard landing, or even a stall close to the ground.
Question 4: What does a SIGMET alert pilots to?
- Routine weather updates
- Pilot errors
- Severe weather conditions (Correct answer)
- Airport schedules
Correct answer: Severe weather conditions
A SIGMET (Significant Meteorological Information) is a weather advisory that alerts pilots to severe weather phenomena that are potentially hazardous to all aircraft. These include severe turbulence, severe icing, widespread dust storms, sandstorms, or volcanic ash. SIGMETs are issued for conditions that are widespread or of significant intensity, requiring immediate attention from pilots for flight safety.
Question 5: What indicates potential aircraft icing conditions?
- High altitudes and turbulence
- Warm temperatures
- Visible moisture and subfreezing temperatures (Correct answer)
- Clear skies
Correct answer: Visible moisture and subfreezing temperatures
Aircraft icing occurs when supercooled water droplets (visible moisture like clouds or rain) come into contact with an aircraft surface that is at or below freezing temperatures. These droplets then freeze upon impact, accumulating ice on wings, propellers, and other surfaces. Both visible moisture and subfreezing temperatures are necessary conditions for structural icing to form.
Question 6: What causes a temperature inversion in the atmosphere?
- Cold front movement
- Nighttime cooling of the ground (Correct answer)
- High humidity
- Rising pressure
Correct answer: Nighttime cooling of the ground
A temperature inversion occurs when a layer of warmer air sits above a layer of cooler air, which is the reverse of the typical atmospheric temperature profile. This phenomenon often happens on clear, calm nights when the ground cools rapidly by radiation, subsequently cooling the air directly above it. The air higher up retains its warmth, creating the inversion layer.
CPL Meteorology and Weather Interpretation 1
What causes wind to flow around high and low pressure systems?