Hail and Damaging Winds in Michigan, July 31, 1999

After a long spell of hot and humid weather, a potent cold front finally moved through southeast Michigan. However, temperatures were able to climb well into the 90s before the front arrived, with dew points in the middle to upper 70s. Numerous severe thunderstorms developed along the front as it moved through, with most of the severe weather located south of Interstate 69.Only one storm produced severe criteria hail. This occurred in Goodrich, where golfball sized hail fell. Otherwise, damaging wind gusts were the severe weather threat. Spotters reported 83 mph gusts just north of Avoca, 70 mph in Brighton and Redford, 60 mph in Saline, Allen Park, Macomb Township, and Rochester Hills, and 58 mph near Metamora.As is usually the case, the main result of these severe gusts was to down trees, tree limbs, and power lines. The hardest hit community was Goodrich, where a garage was moved well off its foundation, a church steeple and a backyard pool were destroyed, and flying debris damaged siding. In Pontiac, a toppled tree punched a hole in a home's roof, utility poles were snapped, and a large sign was tossed through the windows of an indoor flea market. Siding was torn off a building in nearby Auburn Hills. Cars were damaged by fallen trees in Royal Oak and Harrison Township (Macomb County).The number of severe thunderstorms from the 23rd through the 31st was unusually high. Insurance companies stated that there were more damage claims from these late July storms than for any other single weather event since 1983. State Farm Insurance alone reported 7500 damage claims in the entire state of Michigan, worth about $10 million. Allstate reported about 1600 claims, and AAA of Michigan 2000 claims, with no dollar figures available.Area power companies came under some "heat" during this time period. Severe weather, combined with high electric demand due to hot and humid weather, produced frequent and lengthy power outages in some locations. In particular, Detroit Edison received quite a bit of negative press, with over 400,000 customers losing power at some point during the last 10 days of July.