Steaming

This has happened to me twice so far about 2 weeks apart. Once on a 1 hour trip and today on a half hour trip. Every other day I either drive 1 hour or half hour. When I got to my parking lot I noticed steam coming from under the hood. The temp gauge was normal (didn't budge). I popped the hood and noticed it was coming off the radiator. There was no coolant smell and the overflow tank was normal (no bubbling and proper level). It just smelled like steam. I let it idle for probably 5 minutes and it stopped. On both occasions the roads were soaked and it was snowing a real sloppy wet mix. Anyone else experience this? Could it just be the aerodynamics of the car allowing water to come in contact with the radiator and steaming off? I never heard of such a thing though.