Return of Polar Vortex to bring RECORD SMASHING COLD!!!No rest for the weary. On the heels of multiple arctic outbreaks this past week and a heavy snowstorm today, we get to look forward to this… Model data is now in good agreement that we will see another FULL DISPLACEMENT of the POLAR VORTEX later this week! The Euro, shown above, brings the giant, semi-permanent upper low pressure system, all the way down to the Northern Great Lakes on Wednesday.

So what does this mean?  

The arrival of another PV displacement will bring down another frigid arctic air mass during the middle and second half of this week.

Only this time, it will arrive with snow on the ground and plenty of it.  Today’s storm dropped widespread 6 to 12 inch snowfall amounts over Kentucky and much of Southern Indiana.

The Cold Snowballs

Snow always makes the cold that much colder.  In the daytime, it prevents the ground from warming as it reflects much of the sun’s energy.   At night, it acts as an efficient radiator releasing whatever heat that was left from the day back out into space.  Essentially, the snow helps to snowball the cold into even more cold.

So how cold are we talking about?

Here’s a look at the latest data from the GFS (18z run), showing high temps (in white) only topping out in the teens for most of the area and wind chill readings (in blue) falling below zero during the afternoon on Wednesday.   More