polar vortex

Predicting the Polar Vortex

Predicting the Polar Vortex

After the frigid winter we experienced last year, many are looking anxiously at the upcoming winter months, wondering if the dreaded polar vortex will be there to kindly greet us again. You may have heard about the farmer’s almanac predicting another chilly winter or other stories from media outlets making claims about the polar vortex.

In our last polar vortex post, we took a detailed look at the weather patterns last winter during one of the many intense cold outbreaks. We mentioned key facts about the jet stream and mid latitude cyclones and how the orientation of the jet stream can promote the development of mid latitude cyclones. The jet stream and other upper-air (high in the atmosphere) patterns drive the weather near our surface. In fact, we have the jet stream to thank for the ‘polar vortex’ AND the intense drought ongoing in California.

Understanding and Predicting the Polar Vortex Part 1

Understanding and Predicting the Polar Vortex Part 1

On average, the northern half of the United States is colder than the southern half. The boundary separating the cool polar air and the warm tropical air is called the polar front and is a key feature of our atmosphere. Most of the time the polar front is undisturbed, which lends to calm weather. When the polar front starts twisting and turning we get cyclogenesis, the creation of the mid latitude cyclones which bring all the interesting weather to our landscape. The polar front theory was developed in 1917 by Vilhelm Bjerknes and a team of scientists. The theories proposed almost 100 years ago can still explain much of our weather patterns.