Thunderstorm
noun
A thunder rain is a rain that's coming with thunder. For all intents and purposes, if you see this, you'll think thunderstorm.
らいう
The reading is the on'yomi readings. For 雨, you learned it with 雨天. So you should be able to put them together!
今朝の強烈な雷雨で停電になったので、今はインターネットが使えません。
The severe thunderstorm this morning caused a power outage, so I can’t use the internet right now.