Does everyone know when theres gonna be a tornado?

I wouldn't say every tornado but we hear about the bad ones.

People who study the atmosphere can usually pinpoint where tornadoes may occur. They know the atmospheric conditions that are needed.

Not every tornado that occurs in the US will be known by everyone in the US. Usually, the higher rated, more dangerous tornadoes make headline news around the nation.

There are 1000s of tornadoes in the US each year. Most don't even make the local news where they occur.

Generally only tornadoes that occur near populated areas get coverage, and only the really, really big ones (which thankfully are pretty rare) get anything approaching national coverage.

Most tornadoes are not known. The ones that most people hear about are those that cause lots of destruction or when people are killed.