Just thought i'd put in a little something i have learned. One thing witht the wind is that it will never blow in a straight line. There are down and up currents. if your unlucky enough to have a down current near your stand. there will still be a chance to get winded. The only way i have found to try to detect this is to get some bright colored yarn from the crafts dept. and pull a bit off and let it go. The problem i see with the dusts on the market is that they dissapear to quickly. Just my 2 cents proly not worth alot though.