Originally Posted by
CKBA
I suspect two factors - as you mention, in winter the jet stream is stronger so westbound flights are likely to take longer (but conversely, eastbound should be quicker).
The other factor is that the IAH flights tend be routed over Newfoundland and down the Eastern slight of the US - which is where the jet stream sits during the wintertime; SFO/PHX flights tend to overfly Greenland and Hudson Bay and so tend to be less affected by the jet stream.
On a side, I remember extremely fact BOS-LHR and ATL-LHR flights in the past with a tail wind of 100+mph which seriously shortens the trip. Conversely, I have had very slow, tiring westbound flights with not dissimilar headwinds with a LHR-IAD flight taking more than 10 hours! I had a meeting in Geneva a few years ago where many of the participant's westbound (from Asia) flights had been diverted due to low fuel caused by strong headwinds!
Interesting! Are they expecting a particularly bad year for the jet stream or something along those lines? Last winter the flight time was the normal 9h50min, I don't know why this year it's gone up by a whole hour. I too have had issues with westbound flights! Last winter I was on a BRU-PHL flight (US operated 752) that had to divert to BOS to refuel due to the strong headwinds. We actually were meant to divert to Bangor (and had started to decend) when the airport shut, forcing us to go to BOS. This was in addition to the two hour tech delay at BRU- needless to say everyone's connections were messed up! I personally was rebooked three times!
Your explanation would make sense for the SFO/PHX flights! Thanks for that!