rainfall

"In Australia, more than one in 10 houses in Australia are situated in flood zones. Flooding from intense rainfall and overflowing rivers is the most common and costliest natural disaster," said Associate Professor Shi.

Going forward, the study's authors said phosphorus pollution from agriculture needs better prevention and mitigation, which will be a challenge, especially as wetter storms drive increased rainfall and river flows.

Wind gusts could bring power outages, downed trees and high surf along the coastline, the US weather agency said, which issued a "high risk excessive rainfall outlook" for northwest California.

Officials are hopeful the region will only see minor flooding, as few areas have seen any real rainfall this season, so soils should be able to absorb significant precipitation.

Experts say that climate change contributed to the heavy rainfall that caused the floods.