rünkpilved

Rünkpilved, scientifically known as cumulus clouds, are distinct, detached clouds with clearly defined, puffy, or cauliflower-like outlines. They are typically white and appear bright when illuminated by the sun. Their bases are usually relatively flat and dark, while their tops can grow vertically, sometimes reaching considerable heights.

These clouds form through convection, where warm, moist air rises from the Earth's surface, cools as it ascends, and condenses into water droplets or ice crystals. The flat base of a cumulus cloud often marks the condensation level. The vertical development depends on atmospheric stability; in unstable conditions, cumulus clouds can grow into towering cumulonimbus clouds, associated with thunderstorms.

Cumulus clouds are commonly observed on fair-weather days, often appearing in the morning and dissipating by evening. Their presence indicates that the atmosphere is generally stable enough to prevent significant vertical development. However, their appearance can sometimes be a precursor to more active weather if atmospheric conditions change. They are a common sight globally across various climates.