飑线（英语：Squall line），有时亦称线飑。是指带状的雷暴群所构成的风向、风速突变的一种中至小尺度的强对流天气，通常伴随或先于冷锋出现。其破坏性很强大。飑线的产生多是由于冷空气行进至暖湿地区时造成了上冷下暖的格局，使对流层上下热力结构不同，产生高强度的强对流天气。飑线上的雷暴通常是由若干个雷暴单体组成的，因此可以产生剧烈的天气变化。在20世纪早期，飑线通常被用作冷锋的代名词。飑线过境时的典型现象为风向突变、风速快速增加、气压骤然上升以及气温急剧变化，全盛阶段平均风力在10级以上，阵风超过12级。同时也可能伴有雷暴、暴雨、冰雹、强力的直线风、龙卷风和海龙卷风。飑线通常具有典型的弓状特征，并伴随强力的直线风。龙卷风则可能在中尺度低压区存在时沿着波形线状回波存在。在夏季时弓形回波可能会发展为超强对流风暴，并以极高的速度通过大范围区域。雨盾状屏蔽部的后方边缘通常伴随着发展成熟的飑线，并存在尾流低压，有时甚至伴随热暴流。飑线的水平范围很小，长度通常只有150~300公里，宽度仅半公里到几十公里，高度也只有3公里左右。其维持时间一般为4~10个小时。

A squall line is a line of thunderstorms that can form along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front. It contains heavy precipitation, hail, frequent lightning, strong straight-line winds, and possibly tornadoes and waterspouts. Strong straight-line winds can occur where the squall line is in the shape of a bow echo. Tornadoes can occur along waves within a line echo wave pattern (LEWP), where mesoscale low pressure areas are present. Some bow echoes which develop within the summer season are known as derechos, and they move quite fast through large sections of territory. On the back edge of the rain shield associated with mature squall lines, a wake low can be present, sometimes associated with a heat burst.