When that warm air is loaded with water vapor, like Idaho's this week, it takes that vapor with it.
As the water vapor rises, it cools off and condenses into water droplets, forming cumulonimbus clouds that can tower high into the sky, as high as 60,000 feet. As the millions of water droplets fall they create a downdraft of air which creates strong winds in the storm.
If a storm is particularly strong updrafts can carry water droplets to the top of the storm where they are coated with ice and become hail. The stronger the winds are the bigger the hail can get.
Weak tornadoes are possible in storms like these, but Idaho would need even more moisture to fuel the development of powerful tornadoes like they get in the Midwest, and we just don't have access to humid air with all these mountains around.