Get ready for a 'polar plunge': 1st week of winter brings snow and bitterly cold temperatures

Astronomical winter officially begins this Wednesday and Jack Frost will arrive in full force.

Temperatures will take a polar plunge this week, and even Florida won't be spared, thanks to a strong high-pressure system sliding south from Canada.

"Very cold Arctic air masses will envelop much of the central and eastern half of the nation during the two week period, including the busy holiday travel season," the Climate Prediction Center said.

From Idaho to Minnesota, temperatures will range between 10 to 30 degrees below average starting Sunday. By Tuesday, that bitter cold will spread from Washington to Wisconsin and down through Texas, and will become more extreme, with some areas reaching 45 degrees below normal.

"Highs will only reach into the single digits throughout the northern Plains, while lows fall into subzero territory and minus teens closer to the Canadian border," the Weather Prediction Center said. "Gusty winds will make it feel even colder throughout northern Montana, where wind chill advisories are in effect due to the potential for wind chills to dip as low as 30 to 45 degrees below zero."

At those temperatures, hypothermia can start in less than 10 minutes -- but it could be as little as 5 minutes for areas of South Dakota.

The National Weather Service office in Rapid City, South Dakota, noted that wind chills as low as 50 to 60 below zero are possible on Wednesday night.

Even worse, the wind chill advisory is in effect until Thursday. Five whole days of bitterly cold temperatures to kick start the winter season, and it's not just for Montana.

Chilly start to winter

It's that time of year again when everyone hates Florida -- the only real warm spot across the country -- but only for the next few days, since Florida will also cool down by the end of the week.

On Monday, Atlanta will see a high temperature near 50 degrees, but come Friday, that high temperature may not even reach 30 degrees. Denver goes from a high of 46 degrees on Monday down to a high of only 14 by Thursday.

Some Floridians will see a much more sudden drop. Pensacola's high temperature of 64 on Thursday will seem downright tropical compared to the high of 38 just 24 hours later. And yes, this means overnight low temperatures are likely to drop below freezing.

Make sure to cover any plants you may still have outside and bring your pets inside this week.

Even Miami's high temperature of 73 on Friday -- which will likely be the warmest spot across the continental US -- will be nearly 10 degrees cooler than the previous day.

Over the next week, more than 260 million people will see temperatures at or below freezing across the US -- over 80 percent of the population.

"As cold as it will likely be, it will be difficult to challenge daily record lows/cold highs due to this event overlapping with portions of the historic 1983 and 1989 cold waves. At the very least portions of the East may end up seeing the coldest temperatures for any December since 2017."

The cold air is here to stay. Long-range forecast models continue to show temperatures well below normal through Christmas weekend.

"A major storm system is forecast to impact much of the Nation leading up to Christmas Eve, with widespread gusty winds, areas of heavy rain and heavy snow, as well as bitter cold in its wake," the Weather Prediction Center said. "Be sure to pay close attention to the forecast this week as details become certain."

If you are looking for warm weather for the holiday weekend, you will be limited to South Florida, Southern California, or Hawaii.

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