I was asked in November last year to provide a forecast for the winter of 2013 for the province of Prince Edward Island. Normally, a PEI winter (the months of December, January and February) averages -6 degrees Celsius and receives about 41cm of rain or snow. So first, I went to Environment Canada which uses climate models to forecast seasonal weather. Climate models are mathematical equations strung together that describe the physics and chemistry of the atmosphere. These equations are calculated using the largest computers in the country, known as supercomputers. Environment Canada forecast the winter of 2013 to be “warmer and wetter”. I must mention, however, that Environment Canada’s seasonal forecast models are accurate for Prince Edward Island only 40-50% of the time (which is not significantly better than chance, meaning flip a coin and you’ll have the same odds of getting the forecast correct). Environment Canada’s seasonal forecasts are accurate in Northern Quebec, the southern Yukon and Baffin Island, but here on PEI, not so well.
We all know people who swear by almanacs when forecasting the seasonal weather, so I took a look at four of them. The 2013 Canadian Farmers Almanac forecasted the winter of 2013 as “cold and snowy”; the 2013 Harrowsmith’s Truly Canadian Almanac said the winter of 2013 would be “bleak and dreary”; and the 2013 Almanac for Farmers and City Folk’s seasonal forecast for the winter of 2013 would be “normal”. The 2013 Old Farmer’s Almanac, the one we are most familiar with as it has been forecasting seasonal weather since its first issue in 1792 (the time of George Washington’s presidency), uses a “secret formula” kept tucked away in a black tin box at the Almanac offices in Dublin, New Hampshire. The Old Farmer’s Almanac makes claims of 80% accuracy of their results, but studies of their forecasts show no better over the long-term than about 50%. The Old Farmer’s Almanac forecasted the winter climate of 2013 to be “colder and drier” but did promise a “white Christmas”.
My own research at UPEI that examined 140 years of weather observations here in Charlottetown has shown that the climate has definitely gotten warmer and drier, especially over the past 10-15 years or so. And that’s where I put my forecast for the winter of 2013 – to continue the trend and be “warmer and drier”.
Climate is variable, though – it goes up and down. Climate is nature’s merry-go-round so it is often difficult to predict the coming season even with supercomputers, secret formulas or historical trends. To emphasize this point, I asked my boss, UPEI Vice President of Research Robert Gilmour, to flip coins to see what Lady Fortune’s forecast for the winter of 2013 would be – the result being “warmer and wetter”. So there were many forecasts made but only one was correct – my own of “warmer and drier” was the winner as PEI’s winter of 2013 was about 1 degree Celsius warmer than the “climate normal” (30 years of daily records), and less than half the precipitation expected during this season (in spite of all the recent storms).
So what are my weather predictions for the spring of 2013 (months of March, April and May)? Climate records tell us the normal average temperature for spring on PEI is 3 degrees Celsius while the normal precipitation is 31cm. I’ll stick with the historic trends and say the spring will be “warmer and drier”. But I may as well flip a coin, which is exactly what my colleague Carrie Houston did. She held the coins up to her forehead, called on Lady Fortune to provide the answer for the spring of 2013, and flipped them into the air – the result being “colder and drier”. We’ll wait about 90 days and see who is correct.
Questions? Contact Adam Fenech at afenech@upei.ca or (902) 620-5220