From Robert Whitcomb’s “Digital Diary,’’ in GoLocal24.com
A Jan. 31 article in Bloomberg News, “Dangerous Cold Snaps Feel Even Worse Because They’re Now So Rare,’’ puts last week’s arctic attack in perspective. The authors write: “Temperature data since 1970 suggest that sudden freezes used to be much more normal, and the U.S. hasn’t had a good, old-fashioned cold streak in more than two decades.’’ Well, that assertion is debatable, but they usefully cite the work of Ken Kunkel, a researcher at North Carolina State University and the National Oceanic and Atmospheric Atmosphere who for two decades has maintained a “cold wave index’’ record. Bloomberg explains that the index tracks “how often multi-day wintry blasts descend on the U.S.’’ Mr. Kunkel’s chart clearly shows a decline in the frequency of cold waves.
Rapid warming of the Arctic, linked to fossil-fuel burning, has screwed up the jet stream, which in turn sometimes lets big pockets of extremely cold air from Siberia and Canada move into the Mideast and Northeast, even as western North America gets much warmer than “normal’’. Ah, the “polar vortex’’. I love the hysteria that phrase creates!
Then the jet stream waviness changes and Mideast and Northeast turn much milder than normal, which has happened this week. To read the Bloomberg piece and chart, please hit this link.