US west coast

Atmospheric River Slams California
After more than four years of drought, Californians may wonder where the current rain is coming from. Using satellites, NASA scientists have a unique view of the sources of precipitation, and how it reaches the western United States. Rain is often carried by narrow tendrils of moisture called atmospheric rivers that occur all over the world, shown here in white. The atmospheric rivers that affect the western United States are known as the Pineapple Express because they transport water vapor from as far south as Hawaii to California. When the moisture reaches land, it is forced up over the...

IMERG Measures Record Rainfall From Hurricane Delores Remnants

Moisture pumping into southern California and the Desert Southwest from the remnants of hurricane Dolores has caused record July rainfall. This rainfall may provide some drought relief to the state of California that has been in the grip of exceptional drought conditions. Heavy flooding caused an interstate 10 bridge collapse on Sunday July 19, 2015 forcing closure of this main roadway between Southern California and Phoenix, Arizona. Data from NASA's Integrated Multi-satellitE Retrievals for GPM (IMERG) were used to estimate the extreme amount of rain that fell during the past week in that