BOZEMAN – A cooling trend started today with increasing clouds and a few isolated showers and thunderstorms.
A sharp drop in temperatures is coming by the end of the week and lasting through the upcoming weekend. In fact, temperatures could be 15 to 20 degrees below normal for daytime highs this weekend.
A trough of Low-pressure is currently building over the Gulf of Alaska and will slowly dig into the Pacific NW and eventually into the Northern Rockies. This will bring cooler air and a little bit of moisture.
Right now, monsoonal moisture is wrapping around a High-pressure ridge over the central Rockies and lifting up into the southern half of Montana producing isolated showers and thunderstorms mostly over Yellowstone National Park and over into the West Yellowstone area.
Thunderstorms will become a little more widespread Thursday afternoon and there will be a better chance for showers and thunderstorms Friday afternoon through the weekend as the Low spins in from the NW.