Predicting weather like solving puzzle
For John Paul Cragg, predicting the weather is a lot like trying to solve a complex and fun puzzle every day.
“That’s your job, trying to figure out this big, complex puzzle. You try to figure it out and when you get something wrong then you’re better at trying to figure out the puzzle the next day,” said Cragg, a warning preparedness meteorologist with Environment Canada’s Saskatoon office.
“Studying the atmosphere — it’s incredibly interesting and complex. There is so much going on in the atmosphere that we still don’t know or understand. So, it’s a fairly new science.”
Originally from Sudbury, Ont., Cragg, 37, came to Saskatchewan about two years ago. He graduated with a degree in applied physics and a certificate in meteorology from York University in 1996.
After graduation, Cragg worked for about a year with CBC television in Toronto as a weather forecaster. He has been with Environment Canada for seven years.
“That’s what actually got me into weather forecasting. I wasn’t sure what I was going to do after I graduated,” said Cragg, referring to his broadcasting experience.
Cragg explained that the process of formulating a daily weather forecast first involves building a conceptual model of the atmosphere using information such as satellite, infrared and water vapour data as well as radar data, surface observations and readings from weather balloons and airplanes.
“You’re looking at things like where is the jet stream, where are the high and low pressures, how deep are they, where are the warm and cold fronts (and) where is air rising and sinking,” he said.
Because these collection methods are spread out and can’t cover every inch of an area, the data is incomplete.
“You’re always guessing what’s happening in the atmosphere,” he said.
Once gathered, the data is then plugged into a computer program to provide an overall, general picture of what is happening in the atmosphere.
That output is compared to the original conceptual model of the atmosphere. If the two don’t match, then the job of a meteorologist is to try and figure out why there are discrepancies before formulating a forecast. It isn’t uncommon for meteorologists to have different forecasts based on their model and data, Cragg added.
“Even as models are getting better and better, they’re still just an approximation of what the atmosphere is going to be like,” he said.
“You have to pick the best answer because you have to put something down in your forecast,” said Cragg, adding that a forecaster also has to know the level of certainty and likelihood of that outcome as well as the range of other possibilities.
Weather forecasting for Saskatchewan is actually not done in the province. Rather, Environment Canada’s Edmonton office forecasts northern Saskatchewan whereas the southern portion of the province is forecasted in Winnipeg.
Based on weather forecasts, Cragg’s job as a warning preparedness meteorologist is to communicate the likelihood of severe weather to emergency management personnel and the media.
Cragg notes one way Saskatchewan’s weather is different from other parts of the country is that it has more summer severe weather, especially tornadoes.
“We’re right in the heart of it here in southern Saskatchewan,” he said.
A severe weather event that stands out for Cragg happened only a few weeks ago in January, with wind gusts reaching 117 km/h that swept across the province and caused damage and power outages. These were followed by balmy temperatures of 7.5 C in Saskatoon and 9 C in North Battleford.
“It was a pretty interesting storm all in all,” he said.
But in general, a lot of different elements interact that can result in “weird weather” in the province, added Cragg.
“We’re in the middle of a massive plain but we do have mountains that systems have to come over before they can get to us ... and we’re influenced by a lot of different air masses,” he said.
“We can get very moist air coming up into Saskatchewan from the Gulf of Mexico. We can also get drier air coming over from the Pacific and we can get that arctic air from up north. And these air masses come in and collide,” he said.
Also unlike other parts of Canada, in Saskatchewan it is easy to see a weather system several kilometres away.
“That’s really helpful as a meteorologist ... because you can spend your entire career staring at a computer and not interacting with the weather that you’re predicting. And so, it’s really interesting here to be able to forecast and then observe what’s happening and then put the two together,” he said.