I don't know if it's the same in other local markets, but here in the Twin Cities promos for the upcoming local news broadcasts always include some teaser about the weather forecast that goes something like this:

Anchor: Just how cold is it going to get? And will we see any snow over the weekend? Tune in at ten and find out.

I can understand doing such a teaser if the station has an exclusive story or just scooped some recent event that none of the other stations have, but it's not like they're the only place where you can get weather information. There's the Weather Channel, there's the newspaper, and there's the freakin' internet, for crying out loud.