Outlook for this summer's weather? Cloudy with a chance of accuracy

Was Tuesday's hot, dry weather a taste of what the GTA can expect this season? Maybe, maybe not. Depends on who you ask. (KEITH BEATY/THE TORONTO STAR)

Canada’s two leading weather forecast services released their predictions for the summer this week, and wouldn’t you know it? They don’t agree.

The Weather Network predicts overall average temperatures and precipitation. Environment Canada, meanwhile, calls for a warmer, drier summer for much of the country and the GTA.

In fact, the entire summer forecast is more like an outlook, they say. The forecast is really not specific, nor does it focus on a single spot. Instead, the summer forecast – er, outlook – simply provides the personality or character for the upcoming season.

“We have three categories. I mean, talk about generalities. It’s either going to be warmer, colder or in-between,” said David Phillips, senior climatologist with Environment Canada.

“I would never plan my outdoor wedding ceremony or my crop harvesting based on a seasonal forecast.”

How the summer’s weather will shape up is one of those questions that everyone asks, even though they know that no forecast is 100 per cent accurate, says Chris Scott, a meteorologist at The Weather Network.

“People know you’re going out on a limb on this, they still want your best shot,” he said.

Scott’s prediction is based on the belief there will be some fluctuation in temperatures at the start of the season, such as we’ve seen this week, said Scott.

“People should be prepared for getting those shocks of warm weather where it’s quite hot and then cooling down and often times in between, we do get showers and storms,” he said.

Within those transitions from hot to cool, Scott says Toronto may see a bit more rainfall that usual, but not as much as a couple of years ago when the city experienced a wet summer.

Over at Environment Canada, Phillips is more confident in the temperature prediction than the guesses about rainfall.

“It really blows you out of the water,” he said. “There’s just really not a lot of skill in precipitation forecast. We issue it because people want it.”

Predicting summer rainfall is difficult, said Scott, because you can get a heavy storm in one area of the city, while at the other end, the weather is just fine.

In the end, Scott says meterologists can only go as far as science will take them. They don’t provide a precise forecast for a certain day because it is impossible to do, he added.

Instead they try to glean the future by examining the past. “We’re looking at history, looking at previous years, we’re looking at what’s happened in the spring. We’re looking for clues in the atmosphere and especially the oceans,” Scott said.

Canada is difficult to predict, added Phillips, because the country’s weather is so variable.

Seasonal outlooks are simply a matter of satiating curiosity, Phillips said – especially after a dreary spring like the GTA experienced this year. People want to know if there will be light (and sun) at the end of the tunnel.

Of course, other forecasters can offer varying predictions, he said. Sometimes Environment Canada is right, sometimes it’s wrong, but it handles weather in its own way.

“There are different forecasts out there, just like there are different economic models. There are different weather models too,” Phillips said.

The Weather Network’s Scott agrees. “At the end of the day, no two forecasts are alike.”

--Aleysha Haniff and Amanda Khan, Staff Reporters