"...But herein lies the crux—we no longer live in a world without warming. Given that 1985 was the last year with temperatures below the 20th century average, and 2000-2010 was the hottest decade on record, it has become impossible to say for certain that any given storm is free from the influence of our warmed world..." - excerpt from a post at EcoWatch.com; details below.
In Meteorology 1 you learn the atmosphere is most unstable in spring; that's when destructive tornadoes are most likely to touch down on the USA. Yesterday's outbreak was historic; the maps looking like May, not November. Around 80 tornadoes, some large and violent, on the 17th day of November? Surreal.
Weather patterns are shifting north as we continue to warm; more moisture & energy in the system. Yesterday may have been the 8th billion-dollar weather disaster of 2013. According to Aon Benfield 5 of the 7 U.S. billion-dollar disasters in 2013 were related to severe storms & tornadoes; the 3rd highest on record. Only 2011 & 2012 saw more severe storm damage.
A trend? We'll see.
Jeff Masters reports yesterday's "High Risk" was the farthest north an extreme tornado outlook was issued by SPC so late in the season.
Winds ease today; temperatures nudging 50F again Tuesday. A little rain streaks into town Wednesday - a colder front capable of sparking some light snow Thursday night. Nothing "plowable" though.
The next swipe of arctic air arrives Friday; highs hold in the 20s Saturday before recovering next week. GFS data shows 30s to near 40F around Thanksgiving with no big storms.
84 Hour Temperature Trends. NOAA's NAM model of 2 meter temperatures shows plenty of chilly air over the northern USA, a brief warming trend over the central USA Tuesday and Wednesday before much colder air approaches - the subzero isotherm showing up just north of the USA/Canada border by Thursday morning. Loop: Ham Weather.
Map above: Colin Woodard's map of the "11 nations."
* photo above: Renee Schneider.
Photo credit above: "A family outside their makeshift home in Guiuan, Philippines, Nov. 17, 2013. Typhoon Haiyan barreled through the Philippines over a week ago, killing thousands." (Bryan Denton/The New York Times).
Photo credit above: "Editha Ladera, a farmer, surveys the damage to her property in Jaro, Leyte province, Philippines, Nov. 17, 2013. Typhoon Haiyan barreled through the Philippines over a week ago killing thousands." (Jes Aznar/The New York Times).