For the last few years, if not the last few decades, we have enjoyed relatively mild winters in the U.S., especially when compared to those of the 19th and early 20th Centuries. Then came this season of superlatives, slamming the central and eastern U.S. with Arctic air and, this week, bringing ice and snow to the Gulf Coast and Southeastern States.
A seemingly endless series of Clippers, accompanied by strong winds and frigid air, have enveloped the region for most of the winter, threatening lives, triggering accidents, canceling flights, crumbling our infrastructure and disrupting a wide range of human activities. Even those of us who generally welcome the winter season have been looking forward to the "mild interludes," when afternoon highs climb into the upper twenties and thirties (F).
As discussed in previous posts, the extreme winter has been brought to us by a stagnant jet stream pattern that has funneled Arctic air through the Heartland and Northeastern States. While this atmospheric trough has widened in recent days, dropping through the Intermountain West as well, the basic pattern has yet to change and significant relief is unlikely in the near future. Unfortunately, this frigid weather has thrown a cold blanket on the issue of global warming and any meaningful discussion of that important threat will surely be derailed until late spring (at the earliest). Though the stagnant jet stream is unrelated to climate change, it's difficult to spread the faith of global warming when windchills near 50 below plague the Upper Midwest.
