The Polar Vortex is responsible for another round of Maryland cold air this week and this time wind chills can reach the single digits both Thursday & Friday mornings.
What is the Polar Vortex?
The Polar Vortex is a large area of low pressure and cold air surrounding the earth's North & South poles. The vortex is always there and weakens in the summer but gains strength in the winter. This is an "upper level" feature that's several miles above the surface. Therefore, no one actually takes a direct hit from the Polar Vortex, but this pattern can pull arctic air into the mid latitudes like the Midwest and the Mid-Atlantic.
Meteorologist examine temperatures roughly one mile above the surface to assess the severity of the cold air. The air over Maryland this week will be very COLD near -4° Fahrenheit. Next we look at the wind field to see if any of this cold air can reach the surface and this time it can.
Not a Direct Hit
This is only a brush with this weather system. Last time we took a direct it was January 2014, where Baltimore had 15 days below freezing and several nights in the single digits (not including wind chills).