just to pick up on some ones comment above re wind direction.
Be very careful there, don't jump to conclusions. Looking at smoke is only useful in determining wind direction if you are down low.
Using cloud shadows is only useful in determining wind direction if you are around the level of the cloud.
The wind can and does change direction very quickly with altitude at times. An example is dry season in the territory, strong easterly wind on the ground and by the time you get to 10,000 ft it can be a strong westerly !