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Happy winter solstice!

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Today is the first day of winter, at least according to the astronomers. In meteorology, we do our seasons in three-month increments, with winter beginning on December 1. But, we’ll let the astronomers have their day today (ha). The solstice occurs at 10:28 a.m. this morning. That time is determined by the time at which the sun will be directly over the Tropic of Capricorn in the southern hemisphere. That will cause the northern hemisphere to have the shortest amount of daylight of the year, followed by the longest night. I always hear people say today is the shortest day of the year and I want to say, “Nope. They’re all 24 hours.” But that could get me slapped so I don’t (haha).  Our first day of winter is the southern hemisphere’s first day of summer, with today being their longest daylight day of the year and shortest night (exactly opposite of us). Can you imagine celebrating the first day of summer just before Christmas?

To look at our temperature outlook for the next few days you certainly wouldn’t think it’s winter here, for sure. Hopefully we can get some sun in here today and get our temps warmed up to that 60-degree mark. If these clouds get stubborn and hold on, we’ll only make it to the mid 50s.

It looks like the worst weather will hold off until later in the day on Friday now. That system has slowed a bit, which puts the worst of the weather blowing in here Friday night and Saturday. The first half of the day Friday may end up being dry.

We still expect much colder air to filter in here Sunday. Any left over moisture will turn to flurries. I don’t expect any accumulation but I’ll keep an eye on it. Christmas Day looks sunny and dry but very chilly.

The front we have coming Saturday night is what we call an arctic front. Have you ever wondered what exactly that means? Well, my article this week for the Fentress Courier addresses that very question! I’ve included it below. You all have a great day and, again, Happy Winter Solstice!

Arctic Air

During the winter, we often have cold fronts swoop down on us from the north. We all know cold fronts bring colder and drier air, but did you know there are actually two different kinds of cold fronts?

Most cold fronts bring chilly Canadian air with them and we call these polar cold fronts. The air is chilly, but it is not bitter cold. These are the air masses that bring us clear, cool afternoons and crisp, cool nights.

The other kind of cold front is called an arctic cold front. This is the kind of cold front that brings the bitter cold air that can cause record-breaking cold. Arctic air is heavy, which allows gravity to pull it close to the surface. This causes arctic air masses to be very shallow, causing it to act like syrup poured on a counter top, as it slowly spreads across the landscape.

As arctic air encounters mountains, some unique temperature patterns emerge. The higher mountain peaks may actually be above the syrupy, shallow arctic air. We expect it to get colder as we go up a mountain, but with arctic air the coldest air may be at the lower elevations. This can also cause cold air to get stuck in the valleys. This can be a problem if moisture begins moving in, especially if rain falls in the valley and into sub-freezing air.

One of the coldest arctic cold fronts to affect us on the Cumberland Plateau came in January of 1985. Many locations dipped into the twenty to twenty-five degrees below zero range. I don’t know about you, but I hope that kind of arctic cold weather stays up north with the Polar bears!

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