What I look for is 180* direction change, or close to it. While it's happening the speed usually drops to near zero or zero, then picks back up as it blows the opposite direction. During that "lull" is when I expect to see activity. And today was full of those moments. Generally it happens during daylight hours once every week or two. Today was nonstop.
I noticed the pattern while trying to figure out when bucks hit scrapes and why certain days scrape activity is exceptional. Given most scrape activity is nighttime, I also wanted to know what spurred a buck to scrape at say 2pm or 10am. What I found was that specific wind pattern. It's so uncanny that I now plan hunts around it, and take time off when I see it in the forecast.