Weather tracker: ‘Pineapple express’ atmospheric river deluges California

Weather system brings heavy rainfall, strong winds and mudslides. Elsewhere, Nova Scotia declares state of emergency

During the first week of February two storms hit California in quick succession, both featuring intense precipitation thanks to the pineapple express" atmospheric river.

Atmospheric rivers are long narrow channels of very moist air that flow through the atmosphere, transporting impressive amounts of water vapour that eventually fall as heavy rain or snow. The pineapple express is a famous recurring atmospheric river that forms near the Hawaiian Islands and flows northe-east to the Pacific coast of North America.