Using the appropriate unit

I was just listening to an interview on KCBS-AM with a tornado expert about the increase in reported tornadoes in California in recent years. During the interview, the expert mentioned that California tornadoes rarely exceed a 3 on the 5-point damage scale; the interviewer asked what the ratings were.

The expert answered, “well, a tornado rated 2 would destroy a mobile home.”

Of course. What other possible comparison could there be?