A weather alert has been issued as a “Pineapple Express” is hurtling toward the West Coast of the United States

The West Coast is likely to experience heavy rain in the coming days, as the 3,000-mile-long “Pineapple Express” River will bring wet conditions to the region.

Landslides, moderate flooding and high winds are expected over western states like California, Oregon and Washington throughout this week, as the weather system moves east from the Pacific Ocean from Tuesday onward.

Atmospheric rivers are long, narrow regions of the atmosphere that carry water vapor inland from the Pacific Ocean. When atmospheric rivers reach land, they usually release this water vapor as either rain or snow, depending on temperatures, and can sometimes cause heavy rainfall.

The “Pineapple Express” is one such stratospheric river that runs all the way from Hawaii to the western coasts of the United States and Canada, sometimes bringing heavy rain and snow to the region.

In California, from Wednesday through Friday, up to seven inches of rain can be expected at higher elevations while 1 to 5 inches can be expected at lower levels. Current guidance issued Sunday by the National Weather Service (NWS) warns that minor flooding is possible along the San Lorenzo, Russia, and Navarro rivers throughout the day Wednesday. The latter two rivers currently have “a 50 and 65 percent chance of reaching flood stage,” according to a forecast published by the National Weather Service Sunday afternoon.

The NWS does not expect major impacts to local areas despite a deluge of rain on its way to parts of California. “The good news is that our major stem rivers are functioning well and can take a significant amount of runoff before it becomes a problem,” a report released Sunday by the National Weather Service said. “A notable change in this update is the increased likelihood of major upstream rivers rising above flood stage. There is now approximately a 10-30 percent chance of major upstream rivers reaching minor flood stage on Thursday and Friday, with the higher end of those probabilities being North Bay rivers.”

In the San Francisco Bay Area, the National Weather Service warned of the possibility of shallow landslides due to soil saturation due to heavy rainfall levels.

Those areas of Washington may have already seen heavy rain all weekend long, with some rivers in the state already above flood level according to the NWS, and additional rain is on the way thanks to the atmospheric river. “Additional rounds of moderate to heavy rain will be possible through midweek before a cold front finally pushes atmospheric river moisture east of the region late Wednesday into Thursday,” the NWS reported.

In a forecast published Sunday morning, the National Weather Service warned of the possibility of flooding on the Olympic Peninsula and the northern Cascades due to heavy rainfall, although exact amounts expected to fall have not yet been released. Newsweek I contacted the NWS for comment via email.

“This jet stream will be directed directly from west to east, and that means very warm air and a lot of Pacific juice is coming through parts of California into northern New Mexico,” Fox Weather meteorologist Bob Van Dillen said. “We see this fetch coming all the way from Hawaii, and it will extend across the Pacific Ocean to the lower parts of California.”