Hail is a form of solid precipitation that occurs during severe thunderstorms. Its formation involves the following key stages:

Updrafts: In strong convective weather, warm, moist air rises rapidly into colder regions of the atmosphere, where water vapor¹ condenses into cloud droplets².

Freezing Nucleation: Supercooled water droplets (liquid below 0°C) collide with condensation³ nuclei⁴ (e.g., dust or ice crystals) and freeze instantly, forming tiny ice pellets.

Layering Growth: The pellets are carried by updrafts and downdrafts within the storm cloud, repeatedly colliding with supercooled droplets and accumulating layers of ice, like a "snowball effect."

Fall to Ground: When the hailstone becomes too heavy for the updrafts to support, it falls to the ground.

Hailstones vary in size, from pea-sized to as large as golf balls or even bigger, depending on the storm's intensity⁵ and moisture supply.

冰雹（Hail）是一种强对流天气中形成的固态降水，通常伴随雷暴出现。其形成过程主要分为以下几个阶段：

上升气流：强对流天气中，暖湿空气快速上升，遇到高空的低温环境，水汽凝结成云滴。

冻结核心：云中的过冷水滴（温度低于0℃但仍未冻结）与凝结核（如尘埃、冰晶）碰撞，瞬间冻结形成小冰粒。

循环增长：冰粒在云中随上升和下沉气流反复运动，不断与过冷水滴碰撞并冻结，像“滚雪球”一样层层包裹，形成冰雹。

降落地面：当冰雹重量超过气流托举力时，便会降落至地面。

冰雹大小不一，小如豆粒，大如高尔夫球，甚至更大，取决于云中气流强度和水汽含量。