Will brutally cold air in Alaska make its way into the Lower 48 states?

Alex Sosnowski

To say that Alaska has cooled off following amazing warmth from the middle of December would be the understatement of the year.

From their midmonth peak with temperatures as much as 30 degrees Fahrenheit above average, a recent cold blast had temperatures in Alaska hovering 20 to 30 degrees below average during the last weekend of 2019.

"In some cases actual temperatures plummeted to more than 60 below zero," according to AccuWeather Meteorologist Jesse Ferrell.

"A place ironically called Manley Hot Springs, Alaska, dipped to 65 below zero during Friday morning," Ferrell said.

During late December, temperatures in Fairbanks, Alaska, typically range from a low of 15 below zero to 3 above zero. Fairbanks has about four hours of daylight this time of the year.

Alaska has been so cold recently that December may finish with near-average temperatures rather than above average over the interior part of the state. This may be the first month in many for such an occurrence. December is still expected to finish warmer than average in Anchorage and Juneau.

The year 2019 will go in the books as being much warmer than average across Alaska with temperature departures of 2 to 6 degrees above normal.

But, just because much of Alaska has been extremely cold lately does not mean that the Lower 48 States will soon follow suit.

A well-known and long-documented weather system, called the polar vortex, remains strong and has been keeping the deep arctic air pent up near the North Pole.

It is when this feature weakens it then becomes convoluted and allows frigid air to plunge southward toward the midlatitudes.

Some of the extremely cold air is forecast to spread southward over part of western Canada during the first week of January. But, instead of this air lunging head-long into the U.S., the core of the frigid air is likely to be directed toward central and eastern Canada during the second week of the month as the polar vortex shifts farther to the east but remains strong.

"Some cold air will sag and advance from the North Central states to the Southern and Eastern states by the start of the second week of the month, but the most frigid air is expected to remain across Canada," AccuWeather Lead Long-Range Meteorologist Paul Pastelok stated in his blog.

That cold snap in parts of the Central and Eastern states is only likely to last a few days.

"We expect above-average temperatures that linger from late December through much of the first week of January to return during the second half of January," Pastelok said.

This warm anomaly is then likely to wipe out any below-average temperatures from the second week of the month so that January finishes with above average to well above-average temperatures over the eastern half of the nation.

"The polar vortex will remain strong and close to the North Pole so that deep cold air cannot become established in the Lower 48 States," Pastelok stated.

The pattern tends to favor in-and-out cold over the northern tier and not prolonged episodes of frigid weather.

Conditions responsible for below-average temperatures over a large part of the Western states has to do with frequent storms rolling in from the Pacific Ocean.

These storms tend to manufacture their own chilly air in place.

"Since much of this air had its origins over the Pacific Ocean and not the North Pole, it is far from how cold conditions could get this time of the year over the Rockies and Intermountain West," AccuWeather Senior Meteorologist Brett Anderson stated.

"The frequent storms in the West are being fueled somewhat by warmer-than-average water temperatures over much of the Pacific Ocean," Anderson added.

The warm northern Pacific waters have been helping to modify the air over southern Canada.

The storms can still produce periodic low freezing levels along the Pacific coast, such as the case with the recent snow around Christmas in Southern California.

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