FAA Ground School Practice Test

What temperature is forecast for MKC at 6000 ft?

1. -6 degrees C

2. +3 degrees C

3. +1 degree C

4. -1 degree C

The correct answer is: +3 degrees C

Determining the forecast temperature at 6,000 feet involves understanding the general lapse rate, which is approximately 2 degrees Celsius per 1,000 feet of ascent in the troposphere under standard atmospheric conditions. At higher altitudes, temperatures typically decrease due to the decrease in atmospheric pressure and density. If the temperature forecast at the surface (or a lower altitude) is known, you can apply this lapse rate to calculate the expected temperature at 6,000 feet. In this case, if you start from a reasonable surface temperature and factor in the lapse rate, the expected temperature would drop as you ascend to 6,000 feet. The value of +3 degrees Celsius at 6,000 feet suggests that the forecast is considering a relatively warm surface temperature or an inversion layer where temperatures do not follow the typical lapse rate. This makes it the most reasonable choice among the given options, as it indicates that the temperature is still above freezing at 6,000 feet, which is significant for flight operations, particularly regarding conditions related to icing. The other temperature options would suggest colder conditions that may not be consistent with common atmospheric behavior or the understanding of temperature forecasting at that altitude.