Top weather stories of 2020

Heat was the recurring theme for the year, and it manifested itself in many ways

This map shows the total amount of precipitation that fell across the Prairies over the seven-day period ending on December 28. Usually I don’t show these short time period maps, but this map does a great job of capturing a storm system that tracked across the south-central Prairies dropping between five and 15 cm of snow.

Hard to believe another year has come to an end, and for most of us 2020 will be one to remember, but not necessarily for the best reasons.

To begin the new year, I usually take a detailed look back at the previous year and then our customary look ahead to see what the new year may have in store for us. I also review some of the top 10 weather stories, sometimes agreeing with their ranking and sometimes not.

Since, at the time of this writing I am still waiting on a bit more data to complete our look back at the weather of 2020, we will begin this year with a look back at some of the top global and local weather stories.

I must agree with Yale Climate Connections writers Jeff Masters and Dana Nuccitelli, that the biggest weather story of 2020 was what looks to be a record-tying year for global heat. The final numbers will not be in until mid-January, but it appears that 2020 will come in right around the same temperature globally as 2016, which is the current warmest year on record.

Several people like to make the argument that if global warming is really occurring, shouldn’t each year be warmer than the last? Well, the last seven years have been the seven hottest years on record, so yes, each year is kind of getting warmer. There will always be variations from year to year as different large-scale weather patterns ebb and flow across our planet. Take this year for example. There were several large-scale patterns that impacted weather and temperatures across the planet that should have resulted in a cool year.

La Niña was present across the Pacific and sunspot activity was at a minimum – both usually result in cooler global temperatures. There have been arguments that due to the global economic downturn brought on by COVID-19, the number of aerosols in the atmosphere have gone down. Aerosols tend to reflect incoming solar radiation resulting in a cooling effect, so a decrease would lead to more warming.

Unfortunately, like most weather- and climate-related items, aerosols are not simple and easy to figure out. I would probably take at least a couple of articles to try and explain how they impact our weather and climate, and even then, we only have a small understanding of their impact and interactions. I will put this topic aside to tackle in the near future though.

Tied into this topic is the record drop in atmospheric carbon dioxide that occurred in 2020. Thanks again to the economic downturn, global emissions dropped by six to seven per cent, but despite that, atmospheric levels rose by 2.6 parts per million with levels now at 414 ppm. If you have been reading my articles over the years you might remember when I wrote about levels surpassing 400 ppm not that long ago. It will take more than a one-time slowdown of emissions to keep carbon dioxide levels from continuing to rise.

Following up on these top weather stories, let us jump to a couple of Canada’s top weather stories as compiled by Environment Canada, all having to do with heat or cold. Coming in fourth place was the hot summer that impacted Eastern Canada with the occasional taste of that heat in Manitoba. I won’t try to reproduce the whole write-up by Environment Canada but here are some of the highlights:

  • Montreal had it warmest May temperature on record which was also the second-warmest temperature ever recorded in that city for any month.
  • Ottawa recorded its warmest summer since 1921.
  • Temperatures across most of southern Ontario and Quebec were above average from mid-June to mid-August – the hottest period in 145 years.
  • Prince Edward Island had 10 days warmer than 30 C, compared to an average of one.
  • Lake Ontario’s average surface temperature hit 25 C on July 10, a record for that early in the summer.
  • Winnipeg had twice as many 30 C or warmer days than usual.

While Manitoba eastwards had a hot summer, nearly all of Canada had a cold spring. After a relatively mild winter, temperatures in March and April plunged to well below average, which is Environment Canada’s eighth-most-important weather story. The usual culprit when we have cold springs is the polar vortex and last spring was no exception. The polar vortex dropped southwards in March and stuck around until late May in some areas. One of the only positives to come out of the cold spring was it seemed to make it easier to self-isolate as COVID tried to take hold.

To stick with the heat-related stories — the next top weather story of 2020 is that it holds the record for the hottest reliably measured temperature ever recorded. On August 16, at the appropriately named Furnace Creek Visitor’s Center in Death Valley, the temperature hit 54.4 C, which if it holds up to investigation, would be the hottest reliably measured temperature on record. The current world temperature record of 56.7 C, also measured in Death Valley, is not viewed as a reliably measured record. If you are interested in weather records, look up Christopher Burt and Maximiliano Herrera as they are both leading experts on world weather records.

Going to sneak in one more top global weather story that ties into the global heat of 2020 and that is near-record low Arctic sea ice. 2020 saw the second-lowest amount of Arctic sea ice and it is estimated that about three-quarters of the total volume of sea ice has now melted away. Scientists are now predicting that we could see ice-free summers as early as the 2030s which is only a decade away.

About the author

Co-operator contributor

Daniel Bezte

Daniel Bezte is a teacher by profession with a BA (Hon.) in geography, specializing in climatology, from the U of W. He operates a computerized weather station near Birds Hill Park.

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