What's up with the weather?

Tuesday, February 9, 2016

The last two December to February periods were the second coldest back-to-back winters on record for southern Ontario. What can we expect for the next year?

by PHIL CHADWICK

Everyone has been talking about the weather. Ontario is in the middle of a remarkable El Nino winter. Wow. Experts with both real and suspicious credentials write and talk about both sides of the climate issue – the long-term averages of weather. Maybe I am one of those but, in my defence, I have no agenda aside from the truth. Just the facts, ma'am.

For sure, climate and weather are different. Climate is what we expect. Weather is what we get. Let's take a look at the weather from last year with a very special thanks to a climatologist friend for digging up some hard and cold facts.

The last two winters (the December, January and February period or DJF) in southern Ontario (Lower Great Lakes and St. Lawrence) were the second coldest back-to-back winters in 68 years of record, as found in the Climate Trends bulletin. The winters of 1977-78 and 1978-9 were just a tad colder.  

Winter 2013-14 in and around the Great Lakes was not the coldest, but when you expand winter to include November and March (five not three months), it came out to be the coldest such period on record going back to 1948. Otherwise the DJF (2013-4) was only the ninth coldest in 68 years. The five months of cold was significant. DJF (2014-15) was the fourth coldest in 68 years but, with December and March both milder than the previous winter, it was not the duration of winter, but the intensity of the cold that stood out. February 2015 was the coldest month since trends have been examined, beginning in 1948.

What's really fascinating is that, despite one of the coldest winters on record and for sure the coldest February 2015 on record, it was the warmest winter globally. Indeed, the only area globally that was colder than normal was the eastern part of North America from Nunavut to Toronto to Florida. Meanwhile, the Pacific Coast in Canada was the warmest on record (68 years), while in southern Ontario-Quebec it was the fourth coldest on record.

Summer 2014 in southern Ontario and Quebec was minus 0.2 degrees C below normal (42nd of 67 years, ranked warmest to coldest). The growing degree days (GDD) were down slightly across the south. For example, between April and September the GDD in London were 1,933 compared to a normal of 2,001.

We had frost in late May 2015 in eastern Ontario and particularly Prince Edward County. Trenton had a touch of frost on May 22 with minus 0.3 C but had a killing frost on May 23 with minus 2 C. On average, the last spring frost at Trenton is May 1. Only once in 10 years has the last spring frost occurred on or after May 17. There's never been a killing frost so late in 80 years of record. The previous colder temperature was minus 3.3 C in 1936, but that was on May 16. Also of significance was the duration of frost on May 23 – minus 0.3 C at 1 a.m., minus 0.4 C at 2 a.m., minus 0.1 C at 3 a.m., minus 1.5 C at 4 a.m., minus 2 C at 5 a.m. – all with clear skies and no wind. Temperatures during May, before the frost, climbed to 28 C and 29 C, so there was some accelerated plant growth before the frost.

These are simply observations of what happened in the past year or so. What do they mean when we all know that climate and weather have been changing since we crawled out of the cave? The causes and effects of greenhouse gas emissions were first established in 1896 by Swedish scientist Svante Arrhenius. His predictions have been observed a century later.

Similar discussions have been raised about cigarettes and smoking. Factions on both sides argued whether smoking affected public health or not. The medical science was well known, but there were fortunes to be made or lost and experts came out of the woodwork, fuming on both sides of the emotional debate. The facts became obscured by a smoke screen. The science was unequivocal, but there was still confusion and significant percentages of the population continued to smoke and suffer.

The burning of fossil fuels is intimately tied to the oil and coal industries, which are important lobbies in our society. The amounts of money involved are staggering and the powers and institutions built on these fortunes are formidable. Their goal is simply to raise uncertainty. With doubt comes dithering and with dithering comes inaction. With inaction society loses any opportunity to intervene in a thoughtful and positive way to mitigate the impacts of pollution since the start of the industrial revolution. The result has been an omnishambles, a new word that came into the English language in 2012 and was formally added to the online editions of the Oxford English Dictionary in August 2013.

As an analogy, the same process can occur on any day in any weather office. Meteorologist 1 analyses and diagnoses the facts, then prepares a prediction and a warning for some severe event in the future. Meteorologist 2 does not complete the required science or ignores the observations and waits for the severe event to occur before issuing a warning. The second meteorologist might verify better but with no lead time and a message of questionable value to society.

The value of a quality prediction that is not acted upon harkens to a previous article ("Don't bet the farm on the Almanac's weather forecasts," Better Farming, May 2015). The changing climate touches every scale of space and time from the weather right now in the "back forty" acres to the mean temperature around the globe during the past 20 years. There are limitations on how much can be observed and predicted, but to wait until the catastrophe fully happens is not an option for anyone who has empathy and thinks and plans beyond their own existence.

There have been volumes written about climate and weather change – well beyond the scope of this article. Ultimately, each person needs to become informed and make a decision. An intelligent, empathetic decision based on fact and science is the best we can hope for. Anything else must be based on emotion or money.

So what is the forecast for the next year? Any forecast is a gamble, a probabilistic statement of odds (see "Closing the communication gap between farmer and forecaster," Better Farming, August 2014). Persistence can be a great forecast technique. Don't forecast anything to change until it does. What we had last year will happen again next year. We could have added in the prediction of the growing El Nino pattern in the mid-Pacific and the weakening jet stream favouring the polar vortex ("Ontario's changing weather – the jet stream is not what it used to be," Better Farming, December 2014). Without getting too deep into this science, the forecast is for next year is:

Warm and dry along the West Coast. Cold and wintry in east-central North America including Ontario. And for the Maritimes, expect to be slapped by the frontal systems on the east side of the upper trough.

If the El Nino is "super charged," the West Coast warming could be even hotter and drier, while the Polar Vortex could be confined to spin over Hudson Bay and northern Quebec. This would mean a milder winter for Ontario. To quote my source, "Anything is possible."  

It may not be what you want to hear, but please do not shoot the messenger and, of course, any prediction can be wrong. To quote Red Green, "We are all in this together . . . " BF

Phil the Forecaster Chadwick has been a professional meteorologist since 1977, specializing in training, severe weather and remote satellite and radar sensing.