Boise reached 75 degrees on Thursday and will be in the 60s Friday before heavy rain moves into the area.
A tap of tropical moisture arrives in southwest Idaho Friday afternoon. Before that, it will be another mild morning with breezy conditions. When the rain arrives there could be brief wind gusts to 40 mph around 3:15 pm in Boise then the heavy downpours will move in for a few hours.
On Saturday, I expect it to be dry again for much of the daylight hours with another wave of rain showers coming on Saturday evening. It will be cooler on Saturday only in the 50s.
By Sunday, a stronger wave of rain will move in with heavy downpours starting earlier in the day and lasting into the night.
Because the moisture is coming from the southwest, the snow levels will be quite high with 1"-3" of snow falling in the West Central Mountains Friday night above 7500ft. Hunters should expect up to a foot or more snow ABOVE 7500 FEET by Tuesday.