Just noticed ACA157 (YYZ-YEG) diverted into YWG tonight. Currently, back on its way to YEG after about a one hour stop in YWG.
Thinking it may have been medical. How often does this sort of thing occur?
Cheers
Many diversions happen every day, most for minor medical or mechanical reasons, and when the weather acts up, you see tons due to that.
It would be nice if we had a diversion page to list all the diversions in the past day. HintHint* 
flightaware.com/live/flight/ACA1 … /CYYZ/CYEG
Always nice to make reference of what you speak of. Easier for the rest of us to follow up. 
I noticed that ACA157 spent only 1 hr 5 mins on the ground. That makes it more likely to be a medical diversion rather than a mechanical diversion. If it were mechanical and important enough to divert the flight, it wouldn’t be repaired and tested in the short time implied. Conceivably, this could have been removing an unruly passenger, but it seems that in the US, at least, the TSA wants everyone to go through security again. Those flights, then, are delayed two hours or so before resuming their trips to their original destinations.