The first wave of extreme weather conditions from a powerful storm system is making its way across the U.S., bringing heavy rounds of rain and snow to multiple regions.
The storm brought high surf to much of California's coast before it dumped precipitation over a large swath of the West.
As the first system moves over the East Coast, another will come on its heels, inundating the West once again.
MORE: Strong waves pound California coast, injuring at least 8Here is what to expect from the first storms to start the new year:
The first storm began to bring rain to the coasts of Oregon and Washington on Tuesday morning. It was snowing in the higher elevations from Washington to Northern California by Tuesday evening, with rain stretching through San Francisco.
It was raining or snowing throughout much of California by Wednesday morning.
Parts of the Sierras in the highest elevations could see up to 18 inches of snowfall from this storm, with wind gusts up to 45 mph. Winter storm warnings have been issued for areas including Yosemite National Park.
Ahead of the storm, the Sierras measured a below-average snowpack, the California Department of Natural Resources announced on Tuesday with the release of the first snow survey. The state obtains 30% of its water supply from the Sierra Mountain range, according to the department.
In Southern California, up to 8 inches could fall in the higher elevations of the mountains of Los Angeles and Ventura Counties, as well as the Santa Barbara interior mountains.
Up to 2 inches of snow could fall along Interstate 5 at Tejon Pass on Wednesday and Wednesday night, with the potential for significant travel delays due to snow, ice and gusty winds.
The storm will continue east on Wednesday, with winter weather advisories issued in northern Arizona for between 4 and 10 inches of snow for regions including the Grand Canyon and Flagstaff. The timing for this snow is Wednesday night and especially Thursday morning.
The system will then bring the snow with it as it moves over the Rockies on Thursday morning and continues to push east.
Rain will begin from east Texas to Louisiana and Oklahoma on Friday morning, with the precipitation pushing past the Gulf states throughout Friday. The heaviest rain is expected near the coast.
While flash flooding is not a concern in this region due to the fast-moving pace of the system, the National Weather Service advises people who live in areas that flood easily to use caution. The storm will be dumping rain from Florida to Tennessee and the Carolinas by Saturday mornings. Snow is possible farther north, from Missouri to Virginia.
The storm will then trek up the east coast on Saturday evening. Rain is expected in Raleigh and Norfolk, with snow possible in Washington, D.C., Baltimore and Pittsburgh.
Saturday night and Sunday evening, the storm will continue to bring precipitation chances to the Northeast with a mix of rain and snow along the coasts and snow farther inland. For the New York City area, confidence in accumulating snow is highest across the Lower Hudson Valley and southern Connecticut. But it is still too early to have confidence in accumulation amounts.
This is the most significant snowstorm for much of the Northeast in more than a year and has the potential to break record streaks without a 1-inch daily snowfall along the I-95 corridor.
In New York City, it has been a record 688 days since there was at least 1 inch of snow accumulation -- on Feb. 13, 2022. Philadelphia has gone a record 703 days without at least 1 inch of snowfall, and Baltimore has gone a record 716 days.
Washington, D.C., has not seen at least 1 inch of snow accumulation for 716 days, although not a record for the region.
Only 21% of the U.S. is covered in snow right now, which is the lowest for the start of a new year since 2012. The storm should help raise snow cover across the country.
MORE: Passengers on Antarctic cruise ship hit by deadly 'rogue wave' speak outRough waves are expected to hit California this week and through the weekend due to the back-to-back storms.
The high surf advisories begin Tuesday night and will continue through Thursday for much of the California coast, including recently hard-hit beaches and piers.
The northern part of the advisories extend from north of San Francisco to Big Sur, where large breaking waves could reach 23 feet. High surf advisories were in effect for the Bay Area on Wednesday morning and surrounding coastline.
The waves will not arrive to Southern California until Wednesday afternoon.
Beaches in Ventura County, San Luis Obispo County could see waves reach up to 15 feet, while San Diego beaches could see waves up to 10 feet Wednesday afternoon through Thursday.
While these waves are not expected to be as high as the last storm, they will still pose a danger.
Last week, strong waves in Ventura County, California, injured eight people after rogue waves crashed over the seawall and flooded coastal areas.
There will also be an increased risk of ocean drowning, as strong rip currents can pull swimmers and surfers out to sea. Large breaking waves can also cause injury, wash people off beaches and rocks, and capsize small boats near shore. These waves can also move large objects such as logs, crushing anyone caught underneath.
Localized beach erosion caused by the large waves crashing ashore is also possible, officials said.
MORE: 3 dead, 600,000 without power after monster storm tears up the East CoastThe next cross-country storm will begin affecting the Pacific Northwest with rain and snow on Saturday before it moves east through Jan. 10, forecasts show.
Heavy snow will fall near Kansas on Friday morning, while rain inundates regions near Houston and Dallas. The storm will then move across the Gulf Coast throughout the day on Friday, bringing the chance for minor flooding.
By Monday, the storm will have moved out of the West Coast and will be a heavy rainmaker as it treks east in the days that follow, bringing a chance for heavy flooding and strong winds.
The warmer temperatures could also contribute to rapid snow melt from the snow falling from the first storm, which will increase the flood threat.
While the next storm system could be a big snow-maker in the Midwest, the precipitation will likely turn to rain as it reaches higher temperatures in the Northeast. It will be warmer and therefore snow won't spread as far south as with the first storm.
Another round of high surf on the West Coast is also likely over the weekend as the next major storm rolls in.