•Wind Chill Warnings and Advisories are in effect and will expire by tomorrow
•Today is the three year anniversary of HVW!
•The Polar Vortex will begin to depart tomorrow
•Temps slowly moderate starting tomorrow with highs in the upper teens and low twenties
•Chance of light snow saturday night
•Highs will return to the 40’s by the weekend and into next week
All of this Polar Vortex stuff inspired a warmer update for this evening:
In the image below I have circled the Polar Vortex, and drawn a line towards its departing direction over the next few days. So what exactly is a Polar Vortex? As I am sure you have noticed, we haven’t really been on the “Polar Vortex,” “Day After Tomorrow,” “Return of the Ice Age” band wagon with this whole situation. Reason being that the Polar Vortex exists all of the time at both poles, it has existed longer than anyone knows, and will likely continue to exist. They exist in the Summer, and they exist in the Winter.
In laymen’s terms, think of the Polar Vortex as a pool of very cold air that generally spends most of its time near the poles. These pools of cold air are usually kept in place by the polar jet stream, but occasionally it allows this cold air to break off and dive into the lower 48. It happened in 1996 as well as a hand full of times in the 1980’s. Other factors such as snow cover and blocking (Negative NAO) have come together to allow this Polar Vortex to dive fairly far south.
Back to the image of the polar vortex:
Below is a 500mb map (18000 feet above our heads) from the European Model (Euro) showing “low heights” and “high heights”, otherwise known as areas of low and high pressure. All the colors below zero on the scale are “low pressure” above the zero “high pressure.” Just off the right side of the image you can see the “blocking” high pressure that has allowed the jet stream to buckle, otherwise known as a trough. It is this deep trough that has allowed the effects of the Polar Vortex to drop so far South. In the circled green area is our Polar Vortex, where you can see the westerly winds, whipping around its base. We have been feeling those westerly winds for the last 24 hours. The arrow shows the direction that the polar vortex will depart over the next few days as it gets reabsorbed into the main vortex.
Now a look at the Polar Vortex by Friday:
Notice the higher heights developing in its wake? Warmer air is allowed to surge back into the region behind the departing Polar Vortex.
Say “Goodbye” to the Polar Vortex, and say “Hello!” to the atmosphere trying to regain balance with high pressure; in return, warmer temps. In the five images below, you can watch how the temperatures respond to our departing Polar Vortex. Here are five days of high temperatures beginning with Friday and ending with Tuesday, enjoy….
Yes, you reading it correctly! Forties to near Fifties are on their way, we have a few more days of cold but slowly moderating temps, followed by atleast 7-10 days of warmer weather.