Frigid air returning to Minnesota, possibly for an extended stay

We have had a pretty good reprieve over the last month with above average temperatures the majority of the time since the second week of January. But that may come crashing down the middle of this week. Another clipper system will push through the Upper Midwest Tuesday which will bring a wintry mix of precipitation to parts of southern and western Minnesota and a couple inches of snow to the rest of us… possibly 4 or 5 north of the metro. And while even the smallest amount of wintry precipitation can lead to ugly commutes (be ready for that Tuesday), that's not going to last more than a day. What will likely last are much cooler temperatures.

As I have mentioned many times before, the atmosphere acts like a fluid where every single part of it affects everything else one way or another, like a ripple on a pond. So when we are expecting a change in air mass, we look to the origins of that air mass to find out just how cold, or how warm, it will be. Our next one is looking colder and colder.

The images below are courtesy of Ryan Maue and weatherbell.com and are a unique way to view where our air is coming from. Every layer of the atmosphere is connected in some way and what happens to one layer, can and often does happen to another. In the case of these images, we are looking at potential tropopause temperature. I realize those three words just flew over your head, but explained very simply, we look to see the general motion of the atmosphere and where our air is coming from. In this case, we are look way up to the tops of the atmosphere. But this can give us a really good indication of what will take place at the surface too. Take a look at the first…

 

This is what the top of the atmosphere looked like early Monday morning. Just notice the "warmth" of the colors, or lack thereof. That tells you really all you need to know. I have also circled a little blob of white in extreme northwestern Canada. This is where the core of some really cold air lies. Now look where that blob is located Wednesday afternoon…

 

Uh oh! It traveled directly from extreme northwest Canada to Minnesota. So what does this mean?? That the air mass located in northwest Canada Monday morning will be in Minnesota by Wednesday afternoon. Feel a cold chill run down your back? Yep, you guessed it… wicked cold air is on the way. Temperatures in that part of Canada Monday morning were nearly 40 degrees below zero! Now, before you freak out, pack up your minivan, and flee south, we are NOT expecting temperatures that cold. This air mass will moderate as it heads south. It will have 2 days of sun exposure, roll over warmer ground than where it is now, and lose some of its polar characteristics that will allow it to warm a little. That being said, subzero numbers look pretty likely for much of the state Thursday morning, especially in areas with snow on the ground. Just how cold? Well, when you combine the air temperature and the wind, it could be dangerously cold. Here is where one model thinks wind chills will be at 9am Thursday morning...

 

25 to 40 below zero statewide! Ouch! Now, this is NOT a forecast. I am just showing you the potential of how cold it COULD be. So once we get through Thursday are we done with the Arctic air? Well, doesn't look like it. Granted this weekend is a ways away as I'm writing this, but signs are pointing to another arctic blast immediately following this first one and maybe even another one behind that. Let's get back to our temperature map… so here is where we stand Thursday afternoon…

 

Our arctic air mass is here, but the core continues pressing east and is centered toward the Eastern Seaboard which means our temperatures will begin to moderate. But look at the second white blob that's circled… watch where it goes…