2012 Heat Records Demolish Cold Records 14-to-1
It has been a summer to remember. In winter.
This remarkable warmth is associated with a bulging ridge of high pressure aloft that is exceptionally strong and long-lasting for March. While natural factors are contributing to this warm spell, given the nature of it and its context with other extreme weather events and patterns in recent years there is a high probability that global warming is having an influence upon its extremity.
This year, U.S. heat records have been outnumbering cold records by a stunning amount — 14-to-1 (19-to-1 in March) – as this chart from Steve Scolnik at Capital Climate makes clear:
Monthly ratio of daily high temperature to low temperature records set in the U.S. for every month of 2011 and the first half of March, seasonal ratio for summer and fall 2011, winter 2011-2012 to date, and annual ratio for 2011 and 2012, data from NOAA.
I like the statistical aggregation across the country, since it gets us beyond the oft-repeated point that you can’t pin any one record temperature on global warming. If you want to know the historical ratios, see the 2009 analysis, “Record high temperatures far outpace record lows across U.S.,” which shows that the average ratio for the 2000s was 2.04-to-1, a sharp increase from previous decades. Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR), explained, “If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even.”
As Jason Samenow of the Capital Weather Gang notes, this week saw truly “Historic record warm weather“:
Temperatures more characteristic of June have broken hundreds of temperature records over the last several days and promise to continue into the next week in many areas. In some places, temperatures have been an eye-popping 30-40 degrees above normal, nearing or surpassing the warmest temperatures ever recorded so early in the season.
Since Sunday, an amazing 943 new record highs have been broken or tied across the U.S. compared to just 9 record lows
Record highs set Wednesday. Open circles indicate records were tied, circles with an x indicate records were broken.
This is not your father’s climate, as Ostro has documented at great length (see this big PDF):
In recent years I’ve documented hundreds of extreme and/or unusual weather events nationally and globally, but this one is even freaking me out with the nature of the air mass, clouds and downpours yesterday and today, and how the sky has looked so tropical, where I live in the Atlanta area – in mid-March. It’s surreal.
Unfortunately, it’s all too real — and just going to get worse and worse until we act to sharply reduce emissions of industrial carbon pollution.
Meteorologist Dr. Jeff Masters has done some great reporting on this heat wave, in part because he lives in Michigan, which just got slammed by “the earliest EF-3 or stronger tornado in Michigan history, going back to 1950.”
As Masters wrote Friday (emphasis in original):
As I stepped out of my front door into the pre-dawn darkness from my home near Ann Arbor, Michigan yesterday morning, I braced myself for the cold shock of a mid-March morning. It didn’t come. A warm, murky atmosphere, with temperatures in the upper fifties–30 degrees above normal–greeted me instead. Continuous flashes of heat lightning lit up the horizon, as the atmosphere crackled with the energy of distant thunderstorms. Beware the Ides of March, the air seemed to be saying. I looked up at the hazy stars above me, flashing in and out of sight as lightning lit up the sky, and thought, this is not the atmosphere I grew up with.
If we’re going to paraphrase Shakespeare, how about: Now is the winter of our discontent made glorious summer by global warming.
Here’s Masters today on “Summer in March continues for Midwest“: