We are tracking an upper level storm system that will track across the region through the weekend. This will bring a daily chance of showers and temperatures well below normal. Substantial rain is possible Friday and Saturday, especially from Glacier Park south along the divide into the Bozeman area where we could see over an inch of rain.  Highs will be in the 60s to around 70 for most areas, with Butte expecting highs in the 50s on Saturday.  Lows will be in the mid 30s to mid 40s. Tourists and those venturing into Glacier National Park need to be cautious of the much cooler weather.  Snow levels will drop to 6500 feet in the park and 8000 feet across the rest of western Montana.