Northern California is set to experience heavy rainfall and snow from an “atmospheric river,” which is also known as the “Pineapple Express,” according to several reports.
FOX Weather reported that, starting Friday, “Northern California and the Pacific Northwest” could see “the first round of significant precipitation” with forecast models predicting that some places may see “more than 6 inches of rainfall.”
Forecast models show more than 6 inches of rainfall could occur in the highest rainfall accumulation zones, while feet of snow look likely from the extreme northern Sierra Nevada into the Cascades.
“Obviously, when you go up an elevation, you can squeeze out a little bit more of than rainfall,” Haley Meier, a meteorologist with FOX Weather explained. “Overall, snow for portions of Northern California is going to be somewhat limited.”
Meier added that when you move more north “into the Cascades and the coastal ranges,” there is more of a chance of seeing significant snowfall.
Atmospheric rivers are also called the “Pineapple Express” due to the “connection to Hawaii,” according to the Weather Channel.
Historic Pineapple Express -- atmospheric river
— Ryan Maue (@RyanMaue) January 31, 2025
More than 11 trillion gallons of precipitation forecast over the next 7-days across California.
Areas in Sierra could exceed 25 inches -- the amount of rain + snow when melted. pic.twitter.com/Fxwy2GVaV4
According to the National Oceanic and Atmospheric Administration (NOAA), atmospheric rivers can reportedly “vary in size and intensity” and are described as being “long, narrow bands in the atmosphere” that “transport large amounts of water vapor from the tropics,” Newsweek reported.
The NOAA explains that atmospheric river are long, narrow bands in the atmosphere that transport large amounts of water vapor from the tropics. Their size and strength can vary significantly, but on average they carry a volume comparable to the flow of the Mississippi River at its mouth.
Ryan Maue, a research meteorologist, wrote in a post on X that The Kona Low, which is “dumping snow on the Big Island of Hawaii is the same weather system that will impact California with an atmospheric river.”
“The Kona Low dumping snow on the Big Island of Hawaii is the same weather system that will impact California with an atmospheric river,” Maue wrote in his post. “Pineapple Express also needs help of Polar Vortex lobe over Pacific Northwest, where brutally cold air pools for next 1-2 weeks.”
The Kona Low dumping snow on the Big Island of Hawaii is the same weather system that will impact California with an atmospheric river.
— Ryan Maue (@RyanMaue) January 31, 2025
🍍Pineapple Express also needs help of Polar Vortex lobe over Pacific Nothwest, where brutally cold air pools for next 1-2 weeks. pic.twitter.com/UYwF7Bmy33
Millions of residents along the West Coast are about to feel the effects of the "Pineapple Express" – more details: https://t.co/W1lpq2EiQw
— The Weather Channel (@weatherchannel) January 31, 2025
ALL ABOARD THE PINEAPPLE EXPRESS! 🚂🍍
— Brenden Mincheff (@BrendenMincheff) January 31, 2025
Heavy rain this weekend all thanks to a strong atmospheric river originating near Hawaii — aka a Pineapple Express!
Not every atmospheric river is a Pineapple Express, but every Pineapple Express is an atmospheric river!#CAwx #CAwater pic.twitter.com/7kUF2Ma4Ol