A stratocumulus cloud is another type of a cumuliform or stratiform cloud. Like lower altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Like other cumuliform and stratocumuliform clouds, altocumulus signifies convection. This thick cloud layer may be accompanied by embedded towering cumuliform or cumulonimbiform types. Cirrocumulus are, like other members of the cumuliform and stratocumuliform categories, formed via convective processes. Cirrocumulus are, like other members of the cumuliform category, formed via convective processes. These are fair weather cumuliform clouds of limited convection that do not grow vertically. Cumuliform clouds have also been detected on Saturn. In general, small cumuliform clouds tend to indicate comparatively weak instability. Cumuliform clouds generally appear in isolated heaps or tufts. Larger cumuliform types are a sign of greater atmospheric instability and convective activity. Unstable free-convective "cumuliform" clouds are formed mostly into localized heaps. However, with sufficient airmass instability, upward-growing cumuliform clouds can grow to high-towering proportions.