The weather system, also known as an atmospheric river, gets its name from the flow of moisture that periodically heads east from waters adjacent to the Hawaiian Islands to soak the US West Coast.
A Pacific storm system known as the Pineapple Express threatened to dump up to 203mm of rain and 244cm of snow on areas of California, raising risks of flooding and mudslides, meteorologists said on Wednesday.
“The (Pineapple) Express is no joke,” said Bob Oravec, meteorologist with the National Weather Service’s Weather Prediction Center in College Park, Maryland of the strongest weather system of the season.
The weather system, also known as an atmospheric river, gets its name from the flow of moisture that periodically heads east from waters adjacent to the Hawaiian Islands to soak the US West Coast. It blanketed parts of Hawaii with snow over the weekend and is expected to drench California.
The San Francisco Bay area could be hit by flash flooding and falling trees as saturated ground gets up to 203mm more rain and strong winds blow in, the weather service said.
“We’re talking 76 to 127mm of rain in San Francisco and coastal areas in just the next 24 hours, and more on into Friday,” Oravec said.
To the northeast in the Sierra Nevada Mountains, passes could see between 213 to 244cm of snow through Friday.
Valley areas face flood watches over fears the relatively warm Pineapple Express system could initially drench areas as high as Lake Tahoe with rain, melting snow and swelling rivers.