In the first of two planned days of snow, a blizzard will hit the Northeast from Tuesday through Thursday, bringing a dangerous mix of cold temperatures and snowfall.
The weather service has warned of “extremely high snow and wind conditions,” including gusts up to 60 mph.
Snow will be falling in New England, including Massachusetts, Rhode Island and Connecticut.
Snow is forecast for the South, with highs in the 50s and lows in the 20s.
Snowfall totals will be as high as 7 to 10 inches, with some parts of the Northeast expected to get more than two feet of snow.
A few areas of the Southeast could see more than 10 inches.
A blizzard watch has been issued for parts of South Dakota and South Carolina for Thursday, and in Florida and parts of New York and New Jersey, the blizzards could hit Monday.
A snowfall watch for parts in New York, New Jersey and Connecticut for Thursday is in place, and a blizzard watch for New York for Monday is also in place.
The weather service warns that the snowfall could cause serious problems, especially in some areas where people are already dealing with record-setting temperatures.
In many places, especially those in the Northeast, the forecast is already being called for an “extreme snowstorm” that could bring potentially devastating snow, ice and hail.
The blizzard is expected to cause at least some snow and ice to fall in parts of central and southern New England and in parts in the New York City metro area.
Snow could fall anywhere from five to 20 inches in parts along the Connecticut River, and up to six inches in the Bronx, the weather service said.
Snow may also fall in New Hampshire and parts in Maine, New York’s westernmost state.
In the Northeast and along the Gulf Coast, there is also concern that there could be severe, potentially life-threatening snow and rain.
A blizzar can also be expected to hit parts of Alaska on Tuesday and Wednesday.
A record snowfall in the state could be seen by residents in some parts, the Weather Service said.
A blizzard warning is in effect for parts, including Alaska, in the Upper Midwest and northern Florida, with wind gusts of 60 mph or higher possible in some locations.
The winter storm warning is expected for parts near the Canadian border, and the winter storm watch is in force for portions of the Pacific Coast from Alaska to Hawaii.
The Weather Service has issued a snowfall warning for parts along New Jersey’s Atlantic coast and parts on the East Coast from New York to Massachusetts, as well as the Northeast’s coastal counties from Maine to New Hampshire.
The blizzas could cause significant flooding, particularly along the New Jersey-Pennsylvania border.
A storm surge warning is also being issued for areas along the Delaware River from the New England coast to New York Harbor.
Snow could also fall from the Midwest to parts of Iowa, Indiana, Michigan, Wisconsin, Minnesota, Minnesota-Duluth, Ohio, Pennsylvania and West Virginia.
The snow could be a significant risk for people living in areas along highways, and for motorists who drive through areas where the roads are icy.
The storm surge danger is a potential threat for the roads in New Jersey on Wednesday, the National Weather Service warned.
Snow could be heavy enough to affect travel in some cities in the Midwest, especially Chicago and Detroit.
Snow and ice could cause problems in some communities along the eastern seaboard, particularly New York.
Snow and ice in parts can also affect snowfall and travel, with snow in the mountains forecast to be heavy, as will snow in some coastal areas.