I had never heard of a derecho either until we experienced one here at our home 6 years ago, about 4:00 pm on a Saturday afternoon. It is still the only time I've insisted my family all go to our basement. Straight line winds here were clocked at 115 mph, and no advance warning. I was outside telling my 16 year old son bye as he backed the Durango out of the driveway, felt winds suddenly pick up and the sky look weird. Honestly just sensed things weren't right. Nothing like making a teenage boy cancel a date with his sweetheart and then huddle with him in the basement. The winds sounded like a jet, even in my basement. Seven large old oaks came down on all four sides of our home, branches from two brushing the house and one 12 feet away and we never heard them fall. What a pile of firewood. How blessed we felt.