LongHauler From Canada, joined Mar 2004, 4275 posts, RR: 36 Reply 5, posted (6 years 3 months 3 weeks 4 days 14 hours ago) and read 1255 times:
If this flight was due to arrive in YYZ initially, then it was weather related.
Icing aloft was reported moderate to severe, and only one runway was open at YYZ, causing holding up to 40 minutes. As this weather was not forecast until much later, I would guess they did not plan for such a long hold, and diverted to their alternate.
We were tankering fuel into YYZ last night and thus had the fuel for a long hold. Many aircraft were heading to their alternates. (Ours was YOW as well).
Never gonna grow up, never gonna slow down .... Barefoot Blue Jean Night