How our Winter 2016 seasonal forecast stacks up to the rest
Visit the Winter Forecast Guide to the Season for what to expect in the months to come.
Monday, December 7, 2015, 3:07 PM - The Weather Network's Winter Forecast 2016 reveals that El Niño may not have the effect everyone expects in the coming season. How does our forecast compare with the rest?
What everyone is saying
For the full story, including the regional breakdown, check out The Weather Network's Winter 2016 Forecast, however, the basic temperature and precipitation patterns expected by our meteorologists for the next three months are shown below:
"For December, we expect that a mild temperature pattern will dominate most of Canada from British Columbia to the Maritimes as the jet stream pattern will allow Pacific air rather than arctic air to flood across the country," says The Weather Network's Dr. Doug Gillham. "The one exception to this will be northern Quebec, Labrador and most of Newfoundland where temperatures will be near to below seasonal."
"However, a change in the pattern is expected for the second half of winter, especially during February," he adds. "While above seasonal temperatures will continue to dominate the pattern for the western half of Canada, an extended period of classic winter weather is expected from Ontario to the Maritimes as near to below seasonal temperatures will dominate the pattern."
Environment Canada's Dec 2015 - Feb 2016 Seasonal Forecast
Temperature and precipitation forecasts from Environment Canada (shown above and below, respectively) have two maps each. The "deterministic" forecast (left) predicts the expected conditions - above, below or near normal. The "probabilistic" forecast (right) shows the predicted likelihood that those conditions will occur, thus giving the forecast confidence level.
AccuWeather's 2015/16 Winter Forecast
The Canadian Farmers' Almanac Winter Outlook for 2015-2016
How each forecast is made
Some forecasts are produced using a very hands-on approach - analyzing times in the past when there were similar patterns in weather, teleconnections and sea-surface temperatures, and then taking into account how current differences from those past conditions will affect the outcome. Some are the result of complex sets of computer models, generating an "ensemble" look at the future weather, which emphasizes the similarities between the various model results. Others take a combined approach that considers both analogue years and computer model results.
The Farmers' Almanac
The Farmers' Almanac has been around since 1818, and no one — except for their forecaster, Caleb Weatherbee (a pseudonym) — knows how their forecasts are produced.
As written on their website:
The Farmers’ Almanac weather predictions are based on a secret mathematical and astronomical formula. Developed in 1818 by David Young, the Almanac‘s first editor, this formula takes many factors into consideration, including sunspot activity, moon phases, tidal action, and more. This carefully guarded formula has been passed along from calculator to calculator and has never been revealed.
According to editor Peter Geiger, the Almanac draws their seasonal forecasts from its overall yearly forecasts, which are produced two years in advance. It's for this reason that their summer forecast was already pinned to their website as of April 20, 2015.
According to AccuWeather's corporate website: "Many industry leaders consider AccuWeather seasonal forecasts to be their best-kept strategic secret." Thus, the company declined to discuss their forecasting methodology.
In the past, Environment Canada relied on its forecasters taking a very hands-on approach to their seasonal forecasts. Computer model results were adjusted based on their input, typically after examining analogue years for similar weather patterns. However, the decision was made roughly 15 years ago to switch to a pure computer modelling approach.
According to the Environment Canada website, seasonal forecasts are the result of 20 different model runs — 10 each from two different coupled atmosphere-ocean models (CanCM3 and CanCM4).
Forecasters meet to discuss the results before they are released to the public, according to Environment Canada climatologist David Phillips, however no changes are made to those results.
The reason for this, Phillips explained, is to remove the human influence from the forecasts, in order to better evaluate the performance of the computer models.
However, Environment Canada's forecast models are run on a daily basis, and their seasonal forecast website is updated every month. Thus, if Phillips receives a call in the middle of the season for a specific forecast, he will be using the latest model run along with his own vast knowledge of Canadian weather history to guide his answer.
The Weather Network
The Weather Network's forecasting team, led by Dr. Doug Gillham, produces seasonal forecasts using a balanced approach.
According to Gillham:
First, we are continuously tracking weather and ocean water temperature patterns around the world. We are looking for signs that current patterns will continue or change as we go into the next season and beyond.
In addition, we use computer models which are produced by weather services around the world. These models have limited success in predicting how large scale patterns around the world will develop and change during the weeks and months ahead.
Understanding the patterns and how they should evolve is critical to being successful. The models will often disagree with each other or come up with forecasts that does not make sense meteorologically and we need to be able to recognize those errors.
We also seek to identify years in the past that had similar global weather and sea surface temperature patterns and study the weather patterns across North America that were associated with those years.
Years in the past that had similar patterns to our current patterns are called analogue years. Identifying the correct analogue years and researching their associated weather patterns will usually be more helpful than the computer models when it comes to forecasting the weather patterns for upcoming seasons.
Whenever we produce a seasonal forecast, questions arise about whether forecasting the general weather patterns for an entire season, ahead of time, is even possible.
To answer these questions, we'll take a look back to last year, and the seasonal forecasts for Winter 2014/15.
The Weather Network
The Farmer's Almanac
How did everyone do?
Looking at the above forecasts is fairly meaningless unless we actually compare them to what really happened during the season.
For Winter 2014/15, everyone saw what was coming in Atlantic Canada for precipitation. Storm after storm dropped record levels of snowfall across that region of the country.
Since precipitation amounts are trickier to deal with on a seasonal basis, however, where one big storm (or lack thereof) can easily skew a region from one category to the next, we will focus only on temperatures for this comparison.
For temperatures, it appeared as though everyone picked up the basic pattern, but the details came out somewhat different in the end.
In the image above, the temperature anomaly map from WeatherBell, for December 1, 2014 to February 28, 2015, is compared to the four temperature forecast maps.
There were hits and misses. In some cases, the patterns were shifted here and there from what actually happened. The warmth in the west was generally well-represented; as was the cold through the eastern Prairies, Ontario and Quebec.
What’s particularly striking is how The Weather Network’s forecast almost exactly matched the overall pattern of the observed temperatures through the winter. While that success for our forecast team does not necessarily guarantee the same performance for this coming season, it does reveal just how accurate seasonal forecasting can be, and it showcases the strengths of our forecast team's methods.
Related Video: Dr. Doug Gillham talks to Chris St. Clair about the science behind El Nino and how this year may compare to 1997, the last "super" El Nino on record.