CTO Weather Observation & Reporting 4 — Questions and Answers
Question 1: At what point is a SIGMET for convective activity (WST) issued in the conterminous US?
- When severe or extreme turbulence or severe icing is associated with thunderstorms (Correct answer)
- Whenever cumulonimbus clouds are observed
- When thunderstorms affect more than 50% of an area
- When a pilot reports a thunderstorm encounter
Correct answer: When severe or extreme turbulence or severe icing is associated with thunderstorms
Convective SIGMETs (WSTs) are issued for severe or embedded thunderstorms, tornadoes, and hail 3/4 inch or greater.
Question 2: What is the standard duration of a Convective SIGMET?
- Two hours (Correct answer)
- One hour
- Six hours
- Four hours
Correct answer: Two hours
Convective SIGMETs are valid for up to two hours, or until the hazard no longer exists.
Question 3: A TAF includes the group 'TEMPO 1416 6SM -RA BKN030.' What does 'TEMPO' indicate?
- Temporary fluctuations lasting less than one hour and covering less than half of the period (Correct answer)
- Temperature forecast for the period
- Terminal weather expected to persist throughout the period
- Turbulence expected temporarily
Correct answer: Temporary fluctuations lasting less than one hour and covering less than half of the period
TEMPO in a TAF indicates temporary conditions expected to last less than one hour and occur during less than half of the specified period.
Question 4: What does 'BECMG' indicate in a Terminal Aerodrome Forecast (TAF)?
- A gradual change expected to occur within a specified time period (Correct answer)
- Becoming severe weather imminent
- Backup ceiling when main forecast fails
- Boundary conditions for adjacent airports
Correct answer: A gradual change expected to occur within a specified time period
BECMG (becoming) indicates a gradual change in conditions expected to occur within a stated transition period.
Question 5: Which PIREP descriptor indicates severe turbulence that makes aircraft control difficult?
- SEV (Correct answer)
- MOD
- EXTRM
- CAT
Correct answer: SEV
SEV (severe) turbulence in PIREPs indicates abrupt changes in altitude/attitude and aircraft may be momentarily out of control.
Question 6: When must a controller pass a PIREP for severe or extreme turbulence to other aircraft?
- Immediately upon receipt (Correct answer)
- During the next routine position relief
- Only if the pilot requests it be passed
- After verifying with the METAR
Correct answer: Immediately upon receipt
Controllers must immediately relay PIREPs for severe or extreme turbulence to other aircraft that may be affected.
Question 7: What is the lowest RVR value at which an ILS Category I approach may be conducted under FAR Part 91?
- 1800 feet RVR (Correct answer)
- 2400 feet RVR
- 1200 feet RVR
- 2000 feet RVR
Correct answer: 1800 feet RVR
Category I ILS approaches require a minimum RVR of 1800 feet under FAR Part 91 operations.
CTO Weather Observation & Reporting 4
At what point is a SIGMET for convective activity (WST) issued in the conterminous US?