Between now and mid November (then again next April-May) the jet stream will be stronger. This is the prevailing northern hemisphere wind that blows from west to east. Last Saturday, on ORD-YVR, we were late by about 30 minutes due to 100+ knot headwinds, even though we had taken a much more southerly route to avoid the worst of it. Had we gone directly through it, we would have experienced headwinds > 150 knots.

Regards,

Ken Hamer