The clouds can form alone, in clusters, or along acold front in a squall line.
这些云朵可以组成单独的云簇，也可以沿着暴风线的冷锋分布。
2
A squall advancing along a front that forms a definite line.
沿锋面前进，形成了一条确定线的风暴。
3
The squall line is a kind of instable and strong convective weather caused by the air with upper-layer dry and lower-layer wet in front of the upper-troposphere trough.