Why is there strong convective weather under the control of low pressure trough?

1. Thermal factors: the control of low-pressure trough often leads to cooling and dehumidification at high altitude, static instability will increase with the increase of vertical temperature drop rate, and convective instability will increase with the drying at high altitude; At this time, if more unstable energy is accumulated at low altitude, convection can break out under certain disturbance triggering conditions. Most of the low-pressure troughs that cause convective weather are forward-leaning troughs, that is, high-altitude cooling, low-altitude cooling or even heating, and atmospheric stratification becomes unstable, which provides favorable conditions for convective weather.

2. Dynamic factors: Cyclonic shear of low-pressure trough enhances the updraft at high altitude, which provides favorable dynamic conditions for low-altitude convection under the action of momentum downward transfer, so the updraft at the whole layer is more vigorous and easy to trigger convection.