Christmas travel will be an adventure for anyone heading over Oregon's high mountain passes or to the Oregon Coast this year. 

A series of storms are expected to bring anywhere from 12 to 24 inches of snow to Cascade Range passes between the Willamette Valley and Bend.

A flood warning is also in effect for the Central Oregon Coast, according to the National Weather Service in Portland. 

It's good news for skiers and snowboarders, who can enjoy every one of Oregon’s major ski areas being open holiday break.

But it could be a headache for anyone traveling over the mountains or to the coast. 

KGW forecast | RadarWeather app

The action started Saturday evening. 

The National Weather Service has issued a winter weather advisory for all mountain passes above 4,000 feet, including U.S. Highway 20 on Santiam Pass and Highway 58 on Willamette Pass. 

Eight to 16 inches of snow is expected from 4 p.m. Saturday to 4 a.m. Monday. 

"Travel could be very difficult," a NWS warning said. 

But that's not all. 

Another 4 to 8 inches of snow could fall Monday and Monday evening (Christmas Eve) at mountain pass levels, with snow levels dropping down to 3,000 feet.  

“We’re really encouraging people traveling over the Cascades to plan for winter weather — chains, studded tires and all the essentials,” National Weather Service meteorologist David Bishop said. 

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Flood Advisory on the Oregon Coast

As if the snow wasn't enough, a flood advisory was also issued for the Oregon Coast in Tillamook County and Highway 101 due to tidal overflow at high tides, NWS said.

The most likely flooding on Highway 101 is near South Beach and Raymond in Pacific County, and Fraser Road in Tillamook County. 

High tide, and likely road flooding, is most likely 1 p.m. on Sunday and 2 p.m. on Monday.