New Zealand CPL Meteorology (MET) Practice Exam

Altostratus clouds are typically indicative of a middle stage in the development of a weather system that can bring precipitation. These clouds form at altitudes of 6,500 to 23,000 feet and usually cover the sky with a grey or blue hue, often suggesting that a layer of moisture is present in the atmosphere.

When altostratus clouds are observed, it usually signals that a warm front is approaching, which can lead to stable weather conditions that are conducive to the development of moderate to heavy precipitation as the front moves in. The clouds are associated with precipitation that can start as light rain or snow and may intensify, depending on the underlying weather dynamics.

While altostratus clouds themselves do not directly cause heavy thunderstorms or marked turbulence, these scenarios are more commonly associated with cumulonimbus clouds, which develop under different conditions. Additionally, the presence of altostratus typically rules out dry conditions, as they indicate the presence of moisture that is likely to lead toward precipitation. Thus, the statement regarding possible moderate to heavy precipitation is aligned with the typical meteorological conditions associated with altostratus clouds.