Assume a warm air parcel, at sea level, has a temperature of 21°C (70°F) and begins to rise upward. Assume it becomes saturated at 1000 m (3300 ft) altitude, and continues to rise to 2000 m (6600 ft.) altitude. What would the approximate temperature of the parcel be at an elevation of 2000 m (6600 ft.)?

b. 5C (46.4F)

Explanation:

When air that is not saturated rises, it cools at a rate of 10 °C per 1,000 m. The warm air parcel only became saturated at 1,000m so by then it had cooled by 10°C.

Temperature at 1,000 m = 21°C - 10°C

= 11°C

When air is saturated, it is generally assumed to cool at a rate of 6°C per 1,000m. From 1,000m to 2,000 metres the air parcel decreased by a further 6°C bringing its temperature to 5°C.