Polar vortex? If that's what you want to call it...
Though it is a word that has been firmly ensconced in meteorological vernacular for years, the term "Polar Vortex" really came to the public consciousness with a series of arctic outbreaks last winter.
While it's great that more people are learning the term, does it apply to the cool air that is expected to move into parts of the country (including the Tennessee Valley) next week?
A quick Wikipedia search offer this as a definition... "A polar vortex is a persistent, large-scale cyclone located near one or both of a planet's geographical poles."
It is basically an area of low pressure near, for our purposes, the north pole. The air there is obviously the coldest on the planet, and when the jet stream dips southward that cold air is going to follow it. That has happened many times before during the summer. Now we are just attaching a different name to it other than "unseasonably cool air".
This is a little different than the event in January in that it is originating slightly further south.
It is a LOT different in that the air in January cooled to well below zero. We probably won't get that cold.
What we will see is the cool air moving into the northern U.S. on Monday. The high in International Falls, MN on Monday will only reach 60 degrees (78 is average).
On Tuesday, it will slip further south. Highs in Chicago and Detroit Tuesday will reach about 70 degrees (average ranges from 83-85).
It moved into the Tennessee Valley Tuesday afternoon/night. Ahead of the front (leading edge of cool air) we saw numerous showers and thunderstorms Monday night into Tuesday. The high Tuesday will stay at about 82 degrees (90 is the average). The low Tuesday night will drop down to about 60.
We will stay about that cool through the rest of the week.
So, you can call it unseasonably cool. You can go dramatic with POLAR VORTEX! No matter. The cool, dry air will be a nice respite from the heat and humidity we are expecting this weekend.