Which type of weather phenomenon is indicated by the presence of an anvil cloud?

The presence of an anvil cloud is a strong indicator of severe thunderstorms. Anvil clouds form at the top of cumulonimbus clouds, which are associated with intense convective activity, typically found in severe thunderstorms. The anvil shape results from the strong updrafts within the storm that carry moisture and latent heat high into the atmosphere, where it spreads out into the characteristic shape.

In severe thunderstorms, these updrafts can lead to the formation of hail, heavy rainfall, and even tornadoes. The anvil cloud itself can extend for miles and is often a visible sign of powerful storm dynamics at play. This makes it an important feature for pilots and meteorologists in forecasting severe weather and assessing flight safety.

The other options—clear skies, cumulus clouds, and dissipating thunderstorms—do not accurately describe conditions associated with anvil clouds. Clear skies would indicate calm weather with no significant cloud formation, cumulus clouds generally indicate fair weather or light precipitation, and dissipating thunderstorms signify a loss of intensity and the absence of the strong updrafts that lead to an anvil formation.