By Dr. Adam Fenech and Dr. Xander Wang
As the Bank of Canada warns Canadians to brace for a rough economic winter, Islanders are also asking what the weather will be like this winter.
Environment Canada uses climate models to forecast seasonal weather. Climate models are mathematical equations strung together that describe the chemistry and physics of the Earth’s climate system. These equations are calculated using the largest computers in the country, known as supercomputers. Environment Canada forecast average temperatures for the coming winter (December, January, February) for PEI to be “above normal,” with precipitation (snow and rain) “normal” for the Island.
We all know people who swear by almanacs when forecasting the seasonal weather, so we took a look at the predictions from two of them. The 2023 Harrowsmith’s Almanac says the winter will “close to normal” when it comes to temperature but precipitation should be slightly “above normal” with many storms. The 2023 Old Farmer’s Almanac has forecast the PEI winter climate this year to be “above average” temperatures and precipitation.
Our own research at the University of Prince Edward Island’s Climate Lab examining 150 years of weather observations in Charlottetown has shown that the climate has definitely become warmer and drier, especially over the past 10-15 years or so. And that’s where we put our forecast each winter – to continue the trend and be “warmer and drier”.
This inability to forecast seasons accurately is because the year-to-year climate is variable – 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, we flipped coins to see what Lady Fortune’s forecast for the winter will be – the result being “warmer and wetter”. So there are many forecasts made but only one will be correct.
|2022-23 Prince Edward Island Winter Weather Predictions|
|Source||Temperature||Precipitation (rain and snow)|
|UPEI Climate Lab||warmer (+)||drier (-)|
|Environment Canada||warmer (+)||normal (=)|
|Harrowsmith’s Almanac||normal (=)||wetter (+)|
|Old Farmer’s Almanac||warmer (+)||wetter (+)|
|Chance (Flip a coin)||warmer (+)||wetter (+)|
There is a consensus among the many sources pointing to normal or warmer Winter temperatures this year, but no agreement on the precipitation, although the majority points to a wetter Winter than normal. Over the past ten years of predictions, no one of these sources have been “bang on” in predicting the winter climate – the best has been following the long-term climate trends of “warmer and drier” but this only worked five out of the past ten years, and really missed the Island’s savage winter of 2015. Normally, a PEI winter (the months of December, January and February) averages -6 degrees Celsius and receives about 303 millimetres of precipitation, that’s rain or snow. The 2020-21 Winter was warmer than normal (-2.75 degrees Celsius, or 3.25 degrees warmer) and wetter than normal (407 millimetres, or about 34 percent wetter than normal). This matched the predictions of the Harrowsmith’s Almanac and the Old Farmer’s Almanac; and for the first time in ten years,the flipped coins were correct.