A contrasting pattern is setting up across the nation in terms of temperatures, AccuWeather forecasters say.

While some residents across the southwestern United States will be baking in the first projected 100-degree day of the year, those residing in the Northeast will face the total opposite end of the spectrum with daytime highs barely reaching beyond the freezing mark.

The pattern ushering in this notable disparity across the country will be an amplified northward bulge in the jet stream across the West and a dramatic southward dip in the jet across the East.

As a result, this setup allows for an influx of warmth to be transported out of Mexico and into the Southwest while frosty, February-like air out of Canada can filter down across the Great Lakes and Northeast regions.

Northeast: Don't put away the winter coats just yet

The timing of the chilliest air will differ depending on if you are located in the northern Plains or mid-Atlantic and Tennessee Valley. For residents in Minneapolis, for example, the core of the cold will arrive into Monday with highs cresting into the upper 30s Fahrenheit by the afternoon hours.

In Chicago and Detroit, the cooler air will set in from Monday to Tuesday, with both cities projected to only rise into the lower or mid-40s F during this time.

For metro areas closer to the Northeast coast, such as New York City, Providence, Rhode Island, and Boston, daytime temperatures in the 40s will be commonplace from Monday to Wednesday.

"It will feel like winter for many across the Midwest and Northeast at the start of the week as Arctic air surges south from Canada. Temperatures across much of the Midwest and interior Northeast will be as much as 10-20 degrees F below the historical average, and with a gusty wind out of the northwest conditions will feel very chilly," explained AccuWeather Meteorologist Alex DaSilva.

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Following the springtime tease at the end of last week into the start of the weekend when many Northeast locations observed temperatures cresting the 70-degree mark, this return of winterlike conditions will be prominent and even may be disappointing for some.

Overnight temperatures early this week are projected to dip down into the 20s F across much of the Great Lakes and interior Northeast, forecasters note, increasing the heating demand throughout the region.

Snow returns to the Great Lakes, Northeast

Amid the cooler pattern, moisture advancing southward out of Canada and into the northern tier of the country will bring chances for wintery precipitation. While most areas from Wisconsin to interior Maine can experience a burst of snow showers through the early week period, the steadiest snow that falls will be confined to the typical Great Lake snowbelts.

"Along with the cold air will come the risk of snow squalls across western Pennsylvania and New York Monday evening and Monday night. These snow squalls can be particularly dangerous for motorists as they can greatly reduce visibility and drop a quick coating to 1 inch of snow," added DaSilva.

Cities like Erie, Pennsylvania, Buffalo, New York, will be within the corridor to experience a reduction in visibility from Monday to Tuesday as winds pick up and gust as high as 30 mph.

While actual temperatures across northern Wisconsin and Michigan into northwest Pennsylvania and western New York are projected to dip as low as the teens and lower 20s F, AccuWeather RealFeel™ Temperatures early Tuesday morning can range into the single digits for some as blustery winds advance out of the northwest.

Counties in northern Michigan that are still experiencing power outages from the ice storm that occurred over a week ago will be especially vulnerable to the chilly conditions on the way. Nearly 50,000 residents are still being impacted by outages in Michigan as of Sunday, according to PowerOutage.US.

First 100-degree day of the year for Phoenix

Later this week, the heat is expected to build across the desert regions in Southern California, Nevada, Arizona and the surrounding states will not only bring about the first occasion of reaching 100-degrees for cities like Phoenix, but will also challenge daily records.

"Many spot across the Southwest will observe temperatures between 10-20 degrees F above the historical average as the week progresses," noted DaSilva.

While the core of the heat will setup from Thursday to Saturday for most, the surrounding days will still present very warm conditions compared to values observed over the weekend.

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