Western Montana is undergoing an extreme temperature change this week, shifting from 50 degree temperatures up into the upper 70s or even 80s by Saturday. National Weather Service Meteorologist Bruce Bauck says the warm-up is due partially to longer days, but also the arrival of the first high-pressure system we've seen for a long while.

"This spring has been kind of unusual because we've had one weather system after another with lots of clouds and these weather systems have been just full of cold air," Bauck said. "In the eastern pacific, there's a deep weather system that's kind of pumping up air out of the desert southwest and building this high pressure ridge right over the inter-mountain west, late Thursday and Friday the ridge of high-pressure and the air mass will further warm up."

The temperature spikes and drops are starting to look like a cardiogram, and Bauck says this weather warm-up will be gone almost quicker than it arrived.

"This looks kind of temporary, it looks like we're going to have anther weather system plow into the region late Saturday and Sunday and deliver quite a few showers, especially Sunday into Monday and much cooler temperatures, probably back down into the 50s."

Radical temperature changes are nothing new to Montana, but Bauck says they usually happen in the fall, not the spring, and the tendency is for things to get really cold really fast, not to get warmer.