The jet stream has been in a persistent trough over the western United States making for cooler and wetter than average weather. This pattern will not only continue, but the trough will deepen over the west and more rain and even cooler air will move into the Montana.
Friday, the front will move into eastern Montana, dragging cooler air across the state. Highs will be in the 50's with scattered showers and mountain snow showers. Saturday for the Governor's Cup, chilly for runners in the morning. Temperatures will be in the low 40's, and slowly warm into the 50's for highs. It will be mostly cloudy and windy. Sunday, mostly cloudy with isolated thunderstorms, highs around 60. On Monday, another major rainstorm will drench the state
As for rain chances, unfortunately it looks like most of the moisture will stay to the north. Places like Farmington, Dulce, Durango and other areas north could see a few showers. The rest of the state will mainly stay windy.
More detailed outlook
HERE