An area of low pressure across the Southwest will bring the risk for showers and thunderstorms, which could produce some isolated flash flooding through Wednesday.
The Northwest is going to feel cooler air and the chance for storms as a cold front pushes into the region.
Higher elevation snow will be possible across the Northern Rockies.
A cold front also moving into the Eastern Great Lakes and Northeast could bring the risk for heavy rain and some strong to severe storms.
And the calendar may say fall, but above-average temperatures will be the story for much of the Plains and Midwest.
Hurricane Sam strengthened to a Category 4 storm over the weekend and will continue to move to the north.
So far Sam is forecast to stay away from the U.S., but Bermuda will have to watch the track of the system over the next few days.