I will set 3 wind layers
14 - 16k = 20 mph n to s
24 - 26 k = 25 mph s to n
30 and above = 30 mph wing east to west.
I did this to discourage 30k + bombers and escorts. you will burn more fuel and it will take you longer to get to target with this head wind. I may increase or decrease it later on.
It probably won't change the way the Lancasters are employed, but I can see the ingress plan for B-17s being set up to make the flight toward the target at 28K to stay above the S-to-N wind layer, then climbing to just above 30K to make W-to-E runs on the targets, using the 30mph headwind to slow the bombers' ground speed for more concentrated drops, then egressing above 30K to use the tailwind to reduce egress time.
I would suggest that an inconvenient crosswind angle, like 30 mph at 200°, would make a better deterrent to stratospheric bombers than one that can be exploited easily like this.