Check out the awesome video of a dust devil captured by Randy Richardson on Wed. near Vicksburg. Look how high (hundreds of feet) the dust is carried into the air. We also received pics. of a large dust devil near Greenville.
We are having perfect dust devil weather. They form on sunny days and the sun has to be at a high angle. That’s why there most common from May to early August. They are most apt to occur in the early-mid afternoon when the sun is high – not early or late in the day. You need dry conditions. It’s harder to pick up mud. You also need light or calm winds.
Wednesday PM, the relative humidity dropped to 27% in Grand Rapids, 23% in Kalamazoo and just 20% in Big Rapids.
They form when there are two different surfaces – one heated more than the other…like a plowed field next to grass or a parking lot next to a shady area. The heat causes air to rise. As it does, air moves in from the sides to replace it. The air starts spinning as it rises, like it does in a tornado or to a lesser extent around a low pressure center.