I know that everyone has their "2nd winter" hobbit-memes queued-up for the next spring snowstorm, which is pretty inevitable. Since 1960 the only year with no snow in April & May was 1998. It's possible that the snow that we got on April 3rd was it for the year, but there might still be more to come.
But with the start of April our "1st winter" is really over, so lets take a look back. The charts today will all be ones that I've used in the past, and since some of them can be a little bit complicated I'll provide links back to the original explanations.
High Temperatures
Here we have the high temperatures for November through March. This chart highlights the warm & cold records that we broke, and also shows how much time we were above and below the recent average.
In terms of records, we broke 3 all-time record highs: two during the November heatwave, and one during a February chinook. We also had 8 other days which were the warmest since 1996, and 3 which were the coldest.
The red and blue areas emphasize how far we were above or below average. The general story of this winter was:
- November started very warm, and stayed quite warm for the whole month.
- December started with a coldsnap, and after that the temperature jumped around.
- January started with a coldsnap, followed by two warmspells.
- February started with a coldsnap, followed by a warmspell, before cooling off.
- March started with a coldsnap, but the month ended a bit above average.
Low Temperatures
The Lows are similar to the Highs: 14 recent warmest days, including 3 all-time records; and then also 4 recent coldest days during the coldsnaps.
Our coldest days this winter were February 7th at -27.4°C and December 17th at -27.3°C, and then four other days at -25°C. The Edmonton International of course got much colder - dropping below -32°C 4 times - which we talked about in versus - The Edmonton International Airport: Part 2.
The Horserace
We first looked at this chart in Edmonton's Warmest & Coldest Winters, and it shows how the winter of 2016-2017 compared to the last 10 winters, and how they all compare to the 20th century average.
When you add up all of the daily temperatures from November through March the winter of 2016-2017 comes in as our 21st warmest overall. That was helped by the very warm November, and the warmspells of January and February.
And of the last 10 years, 2016-2017 was actually our 3rd warmest winter, although it didn't always feel like it. It comes in just above 2009-2010 and 2014-2015, and well below 2015-2016 and 2011-2012 which were in 1st and 6th spots overall.
In the last 10 years the 2 notably cold winters were 2013-2014 and 2010-2011 in 82nd and 86th respectively, and they were even colder than the average for the 20th century. I find that a little surprising, because while I specifically remember that 2010-2011 was a harsh winter, I'd actually thought that 2013-2014 was fairly mild.
Warmest and Coldest Winters
Here is Edmonton's entire history of warm and cold winters. This one also has a bit of a complicated history, which we originally looked at in Edmonton's Warmest & Coldest Winters.
This shows how much warmer or colder each winter was, compared to the 20th century average. In 21st place, an average day during the winter of 2016-2017 was 2.64°C warmer than the 20th century average. That's just above 2009-2010 at 2.60°C and 2014-2014 at 2.58°C. Those numbers are dependent on the timeframe that we use, and will shift if we decided to start counting in October of December instead of November. But today we will stick with November-March, and looking at the most extreme winters, 2015-2016 was 5°C warmer, and 1886-1887 was 6°C colder.
Things bounce around quite a bit, but with the 5-Year Average we can see that since the mid-1970s the winters have generally been quite warm. Although again we see 2013-2014 (-1°C) and 2010-2011 (-1.3°C) were particularly cold, and in the late-1990s there was a string of cool winters.
Coldsnaps
A few weeks ago we looked at the Really Cold Days this winter:
The winter of 2016-2017 had 25 days below -20°C, which is pretty typical.
When we look at how those cold days were distributed throughout the winter we get this:
Here we have the coldsnaps below -20°C, and the days below -25°C are also highlighted. This is a chart that we first looked at in Coldsnaps & Deepfreezes if you're interested in a bit more background. This chart only goes back to 2010-2011, because showing more years is just too crowded.
Our longest streak of days below -20°C was 6, although December and early-January were pretty busy, with 18-of-the-25 cold days. The longest string of days below -25°C was 3, which is fairly typical for early January. And while the coldsnap in early March seemed like it lasted forever, it was actually only 2 days below -20°C.
Warmspells
The flipside of coldsnaps is warmspells (or perhaps chinooks...) and here we have all of the warm winter days grouped together. This is a little difficult to read, which is ac sort of the point, because we actually get a reasonable number of warm days during the winter.
With 69 days above 0°C and 42 above 5°C we were again pretty typical. The February warmspell is the most notable, with 11 straight days above 0°C, and 6 above 5°C, although the two January warmspells came close to that.
Breakdown
When we take a look at the whole winter, here are how the High temperatures breakdown.
Believe it or not, from November-March about 46% of the days had highs above 0°C. And even during the deepest part of winter from December to February the temperature broke above freezing 33% of the time, and above -5°C about half of the time. With the coldsnaps it's easy to forget the warm days, but this breakdown is pretty consistent for most years.
For Low temperatures there's a lot less orange, because we don't stay above freezing overnight very often.
For this November-March we stayed above freezing 9% of the time (14 days). For December-February it was 4% (5 days), which was actually more warm nights than during last year's warm winter.
For High temperatures we saw that we're above -5°C about half of the time, and the Lows are usually above -10°C about half of the time. That depends a bit on the year though, with cold winters like 2010-2011 and 2013-2014 skewing things a bit.
That feels like a pretty exhaustive look at the temperatures of the slightly-warmish winter of 2016-2017. If you're interested in last year, my less-exhaustive review is here: 2015-2016 Winter in Review. And in a few days we'll take a look at this winter's precipitation (so far).
No comments:
Post a Comment