I'm always puzzled by the impact obstacles (trees, buildings, etc) have on a
crosswind.

On the day ten years ago when I earned my tailwheel endorsement, there was a
15 knot direct crosswind above the treeline. But, the field was buried in a
small gap between 75' trees and the crosswind effectively disappeared once
the airplane descended below the trees. Even better, there was no
turbulence. I'm still surprised at how easy it was to land in those
conditions.

As opposed to yesterday, when I was landing at a nearby field in a 10 knot,
60 degree crosswind. There was a row of 50' trees a hundred and fifty feet
upwind of the runway, and those trees (presumably) created a nasty burble at
groundlevel.

Because of my widely varied experience with obstacles interacting with
crosswinds, I struggle to pick the *best* runway or landing spot. Is it
better to bet on an obstacle reducing the crosswind, or is that obstacle
likely to cause a burble that will result in a rotten (or exciting) landing?
I'm still trying to crack the code on this one...

Thoughts?

KB