Winters (For Most Of Us) Are Getting Shorter

Climatologist Brian Brettschneider did some interesting
number crunching to find that by at least one measure,
winters are getting shorter with climate change. 

 As we launch into a late autumn spell of warm, dry weather, and await winter, we have additional evidence that winters for most areas of the northern and central U.S., and Alaska, are getting shorter. 

Including here in Vermont. 

Alaska climatologist Brian Brettschneider crunched a lot of numbers and posted his results on Twitter, under his handle @Climatologist49.

Brettschneider clearly has a lot more patience with math than I do.  But do check out his twitter feed. It's interesting and very accessible and easy to follow for non-scientists. 

Here's what Brettschneider did:  He looked at 292 weather stations across the U.S.. and figured out for each station what the first early winter five-day period where the average temperature was at or below 32 degrees. He did the same for the last such cold period of the winter at each station.

He compared this data the way it was 70 years ago, and what things are like today.  He found that for 90 percent of the stations, the time between the first cold period of early winter and the last cold period in late winter had shrunk over the past seven decades. That means only ten percent of the stations have had longer winters. 

By at least one measure, winters are getting shorter in
most areas of the United States, including here in Vermont. 

Judging from Brettschneider's map, it seems that in general, the winters grew shorter by the most days in areas near the southern reaches where you can have a long period of sub-freezing winter days. (I posted the map on this post. 

It's interesting that in some areas, sites with shorter winters are in close proximity to ones that had longer winters. This could be due to the vagarities of stations at difference elevations, or whether the measuring site moved a little since the early 1950s.

I see that here in Vermont, the winters have gotten somewhat shorter, according to Brettschneider's data. 

In Burlington, the interval between the first and last five day average of 32 degrees is 10 to 20 days shorter than it was in 1953.  For Montpelier and St. Johnsbury, the change is smaller, amounting to ten days or less.

Interesting, parts of northern New York seem to have had very slightly longer winters, at least under the parameters of this research. 

For us here in Vermont, this data is especially important, given the prominence of our ski industry. I can infer from this data that the period in winter in which ski areas can make snow is growing shorter. 

 And it highlights the difficulty cross country ski centers in low elevations have had in recent winters with warm spells. 

It's all just one of many indications that the times, they are a'changing with the world's climate.