Inspired by the vacuous dimness of one Steven Goddard (http://stevengoddard.wordpress.com/2011/02/14/655-record-lows-66-record-highs/) where he asks, "Why isn't Romm blogging about this?");
and also by my own observation, posted the same day before I read Goddard's piece:
I utilized the same site Goddard used to see what happened over the next week. I generated the following four plots:
Like I said, it's been a warm week, hasn't it? Two weeks, one with lots of low normal temperature records, the next week with lots of high temperature records. Do a little averaging, and you have -- averages.
There's a bottom line here. In any season, there will be cold and warm temperature records. What is more interesting is WHEN the records are being set. Given the set of the jet stream, and Arctic cold heading south (explained by decreasing Arctic sea ice, if you're paying attention), it isn't surprising that this strong storm event set cold records in cold winter. That means that in the past there hasn't been a particularly strong cold snap this particular time in that particular region.
But if the climate is changing -- and things are getting warmer, such that OVER MANY YEARS, with the intrinsic variability of weather always a factor, one would expect to see more warm records EARLIER in late winter, which is where we're getting to now (more like meteorological winter, i.e., December-January-February, than orbitally-defined winter, when the spring equinox is in March.
So, even though La Nina is strong and influencing things, because of global warming, over the next few weeks, the transition time from winter to spring in North America, I would expect to see warm temperature records outpacing cold temperature records, because this time period is when the effects of an earlier spring would be most noticeable.
Using those weekly maps, let's see what happens this year. And next. And the year after that... because we're talking about climate, not weather.
And of course, there's always this:
Record High Temperatures Far Outpace Record Lows Across U.S.