I've had my best luck one day in a total storm, blowing snow, grey, frozen ground. Called in 14 that day, missed the 7 shots I took, came home empty handed. But typically I hardly ever get them to show up when it's like that. I think these were close enough to hear the call due to the noise of the wind, and were quite hungry due to the snow keeping their prey down. But usually do quite well after it gets calm after a storm.