DISCUSSION: Without any doubts, many parts of the contiguous United States have already been “under the gun” with round after round of cold, breezy conditions coming through again and again. Even though we are only in mid-November now, there is no debate that the atmosphere does not always take into full consideration and observe the typical climatology in the context of global air mass regimes according to both latitudinal and longitudinal locations. Many people living across parts of the contiguous United States and across a good portion of central and northern Europe are often very much aware of the fact that Winter weather can strike well before and well after the official start of meteorological Winter. As we head into late November and early December, there is little to no debate that this will very much be the case in the context of an earlier onset of more intense Winter conditions.
This earlier onset of more intense Winter conditions across a good portion of the United States and Europe can be reflected by the tweet which is attached above (courtesy of “@WeatherintheHud” from Twitter), there a number of larger scale features which are scientifically referred to as “Rossby Waves” propagating across the Northern Hemisphere. Rossby waves are effectively larger-scale perturbations in global atmospheric flow which help to transfer heat, moisture, and momentum to different parts of planet Earth at a given point in time. Depending on the number of Rossby waves which are present during a given period, there can sometimes be variable amounts of storminess induced by the progression of successive Rossby waves (or what is also sometimes referred to as a “Rossby wave train”) over a given region over some period. Thus, in looking to the tweet attached above, there is absolutely no debate that there is a heck of a lot of Rossby waves progressing across the larger extent of the Northern Hemisphere at the present time.
As a result of the increased Rossby wave activity, there is an increased concern that the increased prevalence of more frequent larger-scale atmospheric perturbations will more than likely lead to a substantial increase in the degree of Winter storm potential across a good portion of the lower 48 portion of the United States and across much of Europe as well. Thus, it goes without saying that the transition from Fall-time to Winter-time is certainly well underway and there it quite a good chunk of surprises on the way for many millions of people around the world in the coming days and weeks. That is, if things remain on the course they are currently on in the atmosphere across the Northern Hemisphere. As always, please stay tuned for updates on current and future high-impact weather events by visiting the Global Weather and Climate Center.
To learn more about other high-impact weather events occurring across the Polar regions, be sure to click here!
© 2018 Meteorologist Jordan Rabinowitz