Warm weather this past week led to flooding in many areas of western Montana, but it shot an ice jam on Lolo Creek toward the highway and is now being carefully monitored. Hydrologist Ray Nickless with the National Weather Service explains:

"We had what we call break-up ice jams: when you get rain combined with a little bit of snow melt and, you don't have to have a lot of water running in the stream, but just enough to get that ice moving and then you have a domino effect that occurs," Nickless. "It can lead to a mini-flash flood, when it comes through, the water and the ice rise up five or six feet, or even higher than that."

Warning signs popped up on the highway to keep the public aware of the water that had been pushed up into traffic. Nickless says the event has before and it can get worse.

"The magnitude of this last one rivaled similar events that go back all the way to 1996 when we had a massive one break up on Lolo Creek. This was the biggest one I've seen sine that one, this wasn't as big as 1996 event, that one actually ended up going over highway 12 and flooding part of Lolo. This last event actually did come onto Highway 12, though."

Nickless says if another warming event comes with rain, the problem could intensify.