On Thursday, many residents in the eastern U.S. and the Great Lakes region will experience significant winter weather for the first time this season, as a storm brings rain and up to a foot of snow to elevated areas. Light snow may even stretch down to North Carolina, per forecasters’ predictions.

Over 23 million people are currently under winter weather advisories, primarily in the eastern U.S., affecting areas including parts of New York, Pennsylvania, West Virginia, western Virginia, western North Carolina, Kentucky, Indiana, Ohio, and Wisconsin. Additionally, there are warnings in place across northern Washington, Idaho, and Montana, where heavy snowfall is expected through Sunday, according to the National Weather Service.

Winter storm warnings and freeze watches are issued for specific locations through Friday and Saturday. In the northeast, temperatures have dropped significantly from the 60s and 70s on Wednesday to the 40s and 50s on Thursday.

In eastern Wisconsin, snowfall may reach between 3 and 4 inches coupled with wind gusts up to 40 mph. Other winter storm systems are predicted to deliver at least 6 inches of snow to northeast Pennsylvania and southern New York, with higher elevations in West Virginia, Maryland, and southwestern Pennsylvania potentially seeing as much as a foot of snow.

This marks the first considerable snowfall of the season for the central and northern Appalachians.

Meanwhile, a “bomb cyclone” is hitting northern California and the Pacific Northwest with heavy rainfall and strong winds, which has already caused two fatalities. This weather pattern is expected to contribute to flooding, rockslides, debris flows, and additional power outages, according to the National Weather Service.

Understanding warnings, watches, and advisories

The National Weather Service provides winter weather advisories, watches, and warnings when winter conditions may affect your area. Here’s what each term means:

• A winter weather advisory indicates that snow, blowing snow, ice, sleet, or a combination of these elements are expected, but conditions are not severe enough to warrant a warning. Be prepared for challenging winter driving conditions and potential travel issues.
• A winter storm watch is issued when there’s a possibility of significant winter weather occurring within a 48-hour window. It does not guarantee that severe weather will happen; it only suggests it could.
• A winter storm warning is issued for significant winter weather events, such as snow, ice, sleet, or blowing snow. These conditions may make travel difficult or even impossible in certain situations. Consider postponing travel plans until conditions improve.