Originally Published: 21 FEB 22 11:19 ET

Updated: 21 FEB 22 12:13 ET

By Jennifer Gray, CNN Meteorologist

(CNN) -- Beginning today, a series of winter storms will impact the northern tier of the country, mainly from the northern Plains through the Great Lakes.

The Weather Prediction Center (WPC) is describing this as a "significant winter storm." As of this morning, nearly 25 million people are under some sort of winter storm alert.

"A mixture of snow, sleet, and freezing rain may come in two waves to parts of the region," said the WPC.

The first will be a smaller wave today with slightly fewer impacts, mainly just a quick shot of snow or a wintry mix. Then, just behind it -- as soon as Tuesday -- another bigger blast will move through the same areas. And it will leave a mark.

Yet another system will cross the country later this week.

But first things first. Snow will begin impacting the northern states as early as today. Snow across the northern Plains and Upper Midwest will be heavy, with snowfall rates of one inch per hour at times.

"Increasing wind may lead to significant blowing and drifting of snow," the WPC said.

This could lead to near blizzard conditions across this region, including places like Minneapolis.

"Snow rates have reduced visibilities down to 1/2 mile in the heaviest snow, so periods with higher winds could provide occasional blizzard conditions within the band," said the National Weather Service (NWS) office in Twin Cities.

This will create dangerous travel conditions and possible airport delays.

"Total snowfall amounts will likely exceed six inches from the Dakotas into the Upper Great Lakes," said the WPC. "More than 12 inches are possible in some areas over the two days."

Ice is also possible for some places in southern Michigan and southern Wisconsin. However, the forecast is still a little uncertain exactly where the ice will set up. Hardest hit areas could see as much as a quarter-inch of ice.

There could be sporadic power outages and downed trees because of the icing ... not to mention dangerous road conditions, as even a thin layer of ice and snow can cause travel nightmares and traffic jams.

This season, we've already seen people stranded in their cars because of winter storms. In Virginia, people were stuck in their cars for more than 24 hours.

If you must venture out, here are some tips on how to safely drive on ice and snow.

Just a quarter-inch of ice can add tremendous weight to power lines, causing stress and damage and, many times, power outages.

For the big cities along the I-95 corridor, this system will bring all rain. The bulk will impact the region on Wednesday, along with winds gusting as high as 35 mph at times.

Severe weather and flooding

On the south side of the system, warm, moist air will pump into the South from the Gulf of Mexico, providing enough moisture to help create strong storms and flooding. The Storm Prediction Center (SPC) has placed a level two out of five 'slight' risk of severe storms across the southern Plains.

You can track the storms here.

Places like Oklahoma City, Dallas, Little Rock and even Memphis could experience strong to severe storms on Monday afternoon and evening.

By Tuesday, the threat slides a little farther to the east and includes much of the southern Mississippi Valley. Jackson, Mississippi, and Memphis and Nashville will all need to be on the lookout for severe storms Tuesday.

"In addition to severe storms, heavy rain is also a threat across much of the southern US this week," said CNN meteorologist Haley Brink. "Heavy rainfall rates of 1.5 inches per hour will create mainly localized areas of flash flooding through Tuesday."

Nearly 70% of the country will drop below freezing this week

Behind this system, very cold air will move in. Much of the region will see temperatures drop 40 to 50 degrees below normal. More than 15 million people will experience temperatures below zero this week.

Check how cold it will get in your city here.

"Record cold temperatures will be possible today through Thursday across the northern Rockies, northern Plains, and Midwest," said Brink. "High temperatures across the north-central US will be in the single digits today with some locations dropping below zero."

The cold will stick around for much of the week as well, before we start to see a rebound in temperatures.

As the cold air travels down to the South, states along the Gulf Coast will even feel the cold of winter. Parts of Texas could wake up to temperatures below freezing by Wednesday morning.

While this will be cold for the South, it's a far cry from the -20 and -30s the Dakotas and Minnesota will wake up to on Wednesday and Thursday mornings.

"When you factor in the winds, the 'feels like' temperatures across these regions could approach -50 degrees," said Brink. "Frostbite can occur within 10 minutes in these conditions."

Second winter system late-week

Just as you try to recover from the first system, get ready for the next. With so much cold air in place from the first storm system, there will be plenty of opportunities for snow and ice farther south.

The winter system will get its act together in the Rockies, bringing a quick shot of snow. Then, by Thursday and Friday, it will bring snow to places as far south as Oklahoma and even Texas. However, the heaviest snow will stretch from Kansas to Missouri to Indiana.

We could even see major icing in southern Missouri and northern Arkansas, if the forecast models stay consistent.

This system will also have an impact on big cities in the Northeast. By Friday we could see snow in places like Boston, and even a wintry mix in New York City. Speaking of Boston, it could go from highs in the upper 60s on Tuesday, to snow and highs in the low 30s on Thursday.

It's still much too early to fine-tune the details on this one, but this will definitely be something to watch as we get into the latter part of the week.