system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
Why was there a storm in San Francisco last week?


assistant
Last week, there was a storm caused by an atmospheric river. Last Tuesday, more than 200 thousand people in the Bay area lost power because of the storm. It was one of many storms that passed through California this winter.