FAA Commercial Pilot Airplane (CAX)WeatherMedium
A pilot is conducting a preflight briefing and notes a SIGMET for 'FRZLVL SFC-080'. What does this indicate about the freezing level?
- AThe freezing level is at 8,000 feet MSL.
- BThe freezing level extends from the surface up to 8,000 feet MSL.
- CFreezing rain is occurring from the surface to 8,000 feet MSL.
- DThe freezing level is at 800 feet AGL.
Show answer & explanationAnswer & explanation
Correct answer: B. The freezing level extends from the surface up to 8,000 feet MSL.
In a SIGMET, 'FRZLVL' stands for Freezing Level. 'SFC' means surface, and '080' refers to 8,000 feet MSL. Therefore, 'FRZLVL SFC-080' indicates that the freezing level is at the surface, and extends up to 8,000 feet MSL, meaning the air is at or below freezing throughout this entire layer.
Why the other options are wrong
- A. Incorrect. This implies a single freezing level at 8,000 feet, not a range from the surface.
- C. Incorrect. 'FRZLVL' refers to the freezing level, not necessarily freezing rain, although freezing precipitation could occur within this layer.
- D. Incorrect. '080' in this context refers to 8,000 feet MSL, not 800 feet AGL.
SIGMET Freezing Level
In a SIGMET, 'FRZLVL' indicates the freezing level. 'SFC' denotes the surface, and numerical values (e.g., '080') represent thousands of feet MSL, describing the altitude of the 0°C isotherm.
- FRZLVL = Freezing Level.
- SFC = Surface.
- Numbers (e.g., 080) are in thousands of feet MSL.
- Can indicate a single level or a layer (e.g., SFC-080).
- Crucial for assessing potential icing conditions.
Memory trick: SIGMET FRZLVL: Freezing Level, from the Surface, up to the Sky.