Parts of coastal Washington, Oregon and British Columbia may pick up five to 10 times their August monthly rainfall in a matter of hours late this week.

Pockets of severe weather and flash flooding will pose risks in the central and eastern United States into the weekend. A surge of tropical moisture may also increase the flood threat in Texas.

From dry deserts to coastal breezes, factors like wind direction, elevation, and proximity to water shape how often cities across the U.S. reach 100 degrees. Tampa recently marked its first 100-degree ...