A once-in-a-generation cold snap is coming to Maine at the end of this week, as a piece of the polar vortex comes down from the North Pole.

All-time record-low wind chills are on the table to be set in northern Maine. Millinocket’s lowest recorded wind chill is 52 below and the forecast calls for 55 below at this time.

Other parts of the state could see the coldest chills in more than 40 years. If Portland measures a minus 36 wind chill, it would be the coldest since 1981.

The National Weather Service has issued wind chill watches for the entire state of Maine. I expect these watches to be upgraded to warnings before Friday.

Once we get upgraded to warnings it is important to know that the magic number for life-threatening wind chills is minus 35. That’s when you will get frostbite on exposed skin in 10 minutes.

The frigid air moves in during the day Friday and the temperatures will be falling, not rising, throughout the day and night. Have a winter survival kit with extra blankets if you must venture out.

There will also be blowing snow where deep snowpack exists in northern Maine. This will create whiteout conditions and reduce visibility considerably.

So far this season we’ve had a very mild winter with air temperatures (doesn’t include wind chill) only getting to minus 8 in Bangor and 11 in Portland. Last year it was much colder by now.

We won’t break air temperature records, but it will be quite cold, even by February standards in Maine.

The entire state will be well below zero Saturday morning without factoring in the wind chills.

Let’s talk about the coldest time of the day for wind chills during this event. I’m targeting Saturday morning, when wind chills are forecast to be minus 30 to minus 55 degrees.

The reason this is so dangerous is that our bodies normally have a shield around them where we give off heat. That shield, or force field, is removed when the wind blows. Hot air always goes to cold so the heat around our bodies on our exposed skin goes away, leaving us unprotected to the extreme cold.

Please take caution if you are headed out and make sure you have a plan for your pets and animals this week.

By Sunday afternoon temps will improve thanks to a southerly breeze.

Next week will be quite mild by February standards as the weird winter in Maine rolls on.