Answer: a. Heavy rain and thunderstorms followed by lighter stratiform precipitation.
Step-by-step explanation:
In their order of severity, thunderstorms range from single-cell, multi-cell, squall line, supercell, bow line to Mesoscale Convective systems (MCS) . An MCS, therefore is a serious weather condition.
A Mesoscale convective system is an organized, group of thunderstorms with a wide geographical coverage and can last for hours. It can come with hail, flash floods, lake effect snow and trigger disasters such as tropical cyclones.