A large swath of the country is being walloped this week by wintry weather, with two rounds of arctic cold Monday that were forecast to be followed by a potentially disruptive winter storm that could last into the weekend.
On Monday morning, 77 million people woke up to cold weather alerts across two regions, the first from the northern Plains to the Northeast and the second across Florida.
Wind chills were as cold as 20 to 30 below zero in northern cities like Chicago and Albany, New York — and 20 to 30 degrees in Florida cities that rarely experience such frigid weather, like Tampa and St. Petersburg.
While the cold alerts were expected to expire by midmorning in Florida, it was still chillier than usual in the state with afternoon highs remaining 10 to 25 degrees below average.
Monday was forecast to be the coldest day for the Upper Midwest and Great Lakes regions, and Tuesday will be the coldest day for the Northeast.
New York City, for example, was bracing for wind chills in the single digits and the teens for most of Tuesday.
Monday's snow was spread across the Great Lakes, where heavy lake-effect snow blanketed the typical snowbelt areas downwind of the lakes.
As of Monday afternoon, more than 8 inches of snow had been reported in parts of Michigan and New York and more was expected to fall, with snow bands forecast to continue through Tuesday downwind of lakes Michigan, Erie and Ontario.
Harsh winter weather was being blamed for a 100-vehicle pileup near Grand Rapids, Michigan, that forced police to shut down Interstate 196 in both directions for hours,NBC affiliate WOODreported.
In addition to lake-effect snow, the next clipper system will dive out of Canada on Tuesday and bring a round of snow to the Dakotas, Minnesota (including light amounts for Minneapolis) and Iowa.
On Wednesday, the same clipper will zip across the Great Lakes and give Chicago a dusting in the first half of the day, then bring some snow to the interior Northeast and New England by the second half.
While the cold and snow in the first half of this week will make for wintry scenes, the snow totals will not be blockbuster, and the cold is not expected to set any records.
That having been said, then next round of winter weather arriving later this week could be both record-setting and disruptive.
Beginning Friday, the next blast of arctic air will affect the northern Plains and the Upper Midwest first, then other parts of the Plains, the Midwest and eventually the Southeast and the Northeast through the weekend.
Wind chills this weekend are forecast to be as cold as 30 below zero, with some localized areas experiencing wind chills that could be as cold as 40 to 50 below zero. For the Northeast and New England, wind chills are already forecast to be below zero by Sunday.
The cold temperatures this weekend will be the coldest air of the season so far and very well may ultimately be the coldest air of the entire season.
How far the arctic air plunges south will determine the scope of a winter storm in the making. As of Monday morning, the signal was growing for a high-impact winter storm that could bring widespread snow and ice across the southern tier of the U.S. from Friday through Sunday.
The system is likely to affect the southern Plains, the lower Mississippi Valley and the Southeast with wintry precipitation. There is also potential for the wintry precipitation to spread north into the Northeast over the weekend, but forecasters warned there is too much uncertainty about the potential for any more detail so far in advance.
Forecasters also cautioned that even as model guidance converges on the possible scenarios surrounding the winter storm, it is still impossible to predict exact details of precipitation amounts and where the rain, snow and ice line will set up.
However, meteorologists were confident enough Monday to start messaging about the potential risks for people who may be affected, including the National Weather Service in Fort Worth, Texas, which warned of freezing temperatures and the potential for a messy wintry system this week.
As the forecast comes into better focus, it is looking more and more likely that the second half of January will send shivers through nearly everyone from the Rockies to the East Coast.
