Perhaps Try FL250

[pelmet]

It might be safer, more legal, and more comfortable for the pax....

C-FONK, a WestJet Boeing 737-8CT was conducting IFR flight WJA1681 from John F. Kennedy
International Airport (KJFK), NY. to the Calgary International Airport (CYYC), AB. While enroute
approximately 20 nm west of the Virden Aerodrome (CYVD), MB, the aircraft entered an area of
severe turbulence while cruising at FL380. The flight crew had difficulty maintaining flight
parameters and safe performance margins. The flight crew requested an immediate descent to
FL360. The aircraft descended, but the turbulence continued. The auto pilot would not remain
engaged. Air traffic control approved a block altitude between FL340 and FL360 and the captain
manually flew the aircraft until conditions improved. No upset attitudes occurred and the flight
continued to CYYC without further incident. The operator's maintenance department subsequently
conducted a post-turbulence inspection with no defects found.


....from TSB.

[CpnCrunch]

Why FL250? Radar at the time shows what seems to be a line of thunderstorms all along the SK/MB border up to The Pas and down to South Dakota. GFA says "FRQ CB 460". Looks like you can't get around or over them. Would going lower work?

If you have a premium windy.com sub you can see the winds at various altitudes on that day (I don't), but I'm guessing there wasn't much they could have done, other than perhaps a massive diversion earlier. But if you did that you'd have to head initially towards Wyoming or the top of Lake Winnipeg, neither of which seems all that reasonable. At the time of departure there was nothing on the radar in that area at that time, so you couldn't really have predicted it anyway.

[pelmet]

Why FL250? Radar at the time shows what seems to be a line of thunderstorms all along the SK/MB border up to The Pas and down to South Dakota. GFA says "FRQ CB 460". Looks like you can't get around or over them. Would going lower work?

If you have a premium windy.com sub you can see the winds at various altitudes on that day (I don't), but I'm guessing there wasn't much they could have done, other than perhaps a massive diversion earlier. But if you did that you'd have to head initially towards Wyoming or the top of Lake Winnipeg, neither of which seems all that reasonable. At the time of departure there was nothing on the radar in that area at that time, so you couldn't really have predicted it anyway.

Hmmm...admittedly, I assumed CAT and not mixing it up with big thunderstorms. In that case, don't be surprised if you end up in an interesting situation.

[CpnCrunch]

Hmmm...admittedly, I assumed CAT and not mixing it up with big thunderstorms. In that case, don't be surprised if you end up in an interesting situation.

No worries. I just find it interesting looking back at the weather for incidents like this.

Sitting in the back in CAT I've looked at windy to see what the situation is when there is free internet. I'm wondering if you use that or any similar tools to decide what to do, other than just asking ATC what others have reported. You can pretty much instantly see exactly where the wind shear is at various altitudes. (Assuming of course that the model is accurate).

[Nauclerus]

Appears to have been this flight

https://www.flightaware.com/live/flight ... /KJFK/CYYC

At the time the winds were between 80-100 knots from the south.

The only other traffic in the area at the time was another Westjet flight 1611 also at FL380.

https://www.flightaware.com/live/flight ... /KORD/CYYC

1681 appeared to deviate even further north around the weather than 1611. I wonder what 1611's ride was like ?

[pelmet]

Appears to have been this flight

https://www.flightaware.com/live/flight ... /KJFK/CYYC

At the time the winds were between 80-100 knots from the south.

The only other traffic in the area at the time was another Westjet flight 1611 also at FL380.

https://www.flightaware.com/live/flight ... /KORD/CYYC

1681 appeared to deviate even further north around the weather than 1611. I wonder what 1611's ride was like ?

Your mention of the wind direction combined with the forecast thunderstorm heights and picture of very long thunderstorms reminded me of an incident report that I read long ago and took into account whenever I saw those giant thunderstorms. Give them wide berth as I also read that their size can create widespread disturbance outside of them…..

https://aviation-safety.net/wikibase/190638

Upwind is not so bad as downwind.

[pelmet]

Appears to have been this flight

https://www.flightaware.com/live/flight ... /KJFK/CYYC

At the time the winds were between 80-100 knots from the south.

The only other traffic in the area at the time was another Westjet flight 1611 also at FL380.

https://www.flightaware.com/live/flight ... /KORD/CYYC

1681 appeared to deviate even further north around the weather than 1611. I wonder what 1611's ride was like ?

Your mention of the wind direction combined with the forecast thunderstorm heights and picture of very long thunderstorms reminded me of an incident report that I read long ago and took into account whenever I saw those giant thunderstorms. Give them wide berth as I also read that their size can create widespread disturbance outside of them…..

https://aviation-safety.net/wikibase/190638

Upwind is not so bad as downwind.