Avalanche warnings have been issued for areas across Washington and Oregon in preparation for the weather event known as the “Pineapple Express.”

Starting Sunday, the atmospheric river event is expected to bring a heavy amount of mountain snow and rain, CNN reports. Since the terrain in areas in the path of the Pineapple Express are already covered from previous storms, flooding and natural avalanches are possible.

The Northwest Avalanche Center issued a level 4 “high” avalanche danger warning for Sunday and avalanche warnings have also been issued for the Cascades across Washington. On Saturday, a snowmobiler in Idaho became the seventh person to die in an avalanche this winter.

“This will mark the beginning of a wet period across Western Washington, as the southern periphery of the Atmospheric River will affect the region before it shifts southward over the area Monday,” the Seattle office of the National Weather Service stated.

The gusty winds and flooding that will occur during the Pineapple Express could cause power outages in both Washington and Oregon.

The weather phenomenon occurs when a storm develops in Hawaii and then moves across the Pacific Ocean to the western parts of North America. “When it reaches the West Coast, the Pineapple Express can dump as much as five inches of rain on California in one day,” the National Oceanic and Atmospheric Administration reports.

The Pineapple Express isn’t the only powerful storm to hit the U.S. lately. Millions of residents in Texas have been left without power since Tuesday following a brutal winter storm, and much of the country is still thawing out from last week's polar vortex plunge.

The impact in Texas was so severe that President Joe Biden declared a major disaster for a majority of the state, NBC News reports.

“I thank President Biden for his assistance as we respond to impacts of winter weather across our state,” Texas Governor Greg Abbott said in a statement.

“While this partial approval is an important first step, Texas will continue to work with our federal partners to ensure all eligible Texans have access to the relief they need.”

Biden’s declaration will allow the affected communities in Texas to receive federal funding.

Pineapple Express storm
Storm-watchers look at high waves during intense weather in Depoe Bay, Oregon Dec. 10, 2014. High winds and heavy rain are expected through Thursday. Reuters/Steve Dipaola