21st Anniversary of the Great Derecho of 1998

Bill's Blog
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Today is the 21st anniversary of the famous “derecho” thunderstorm outbreak of 1998. A derecho (Spanish for “straight”) is a fast-moving line of thunderstorms that produces a wide and long swath of significant wind damage.  Around 5 AM that Sunday morning, the storms blasted through West Michigan with winds estimated as high as 130 mph in Grand Haven, Spring Lake and Walker. According to the Storm Prediction Center, this episode ranks as one of the top thunderstorm events in world history! 

A large area of significant wind damage occurred from South Dakota all the way to the East Coast. In Michigan, there were 4 fatalities and 153 people were injured.  At one point, not a single stoplight was working between Grand Rapids and Baldwin. The toll would have been much worse if the storms came in the afternoon instead of in the early morning when most people were asleep in their homes.

I went out to visit Spencer, S.D. where the worst tornado occurred as the supercells first formed. That small town was pretty much wiped out. Only two blocks in the entire town were spared significant tornado damage. The tornado was an EF4 and was the most destructive tornado in the history of the state. The tornado occurred at sunset and afterward it was soon dark. It was mid-morning before some of the victims were found. A portable Doppler radar indicated winds of 220 mph with that tornado. In a town of 315, there were six fatalities and nearly half the town residents who where there that night were injured. The population of the town dropped to 145 after the tornado.

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The supercells eventually formed the line that raced from eastern S.D. to Massachusetts and out into the Atlantic Ocean. Eighteen years later you can still identify swaths where most of the trees were blown over (White Lake exit on US 31 – the Spring Lake Cemetery). Here’s a radar loop from S. Dakota to Michigan. Read more here, here, and here. Storm Reports here (pages 2 – 8). The 1998 storm was a “once in a lifetime event”. The storm line formed in S. Dakota and the line went 400 miles out into the Atlantic Ocean before the storms dissipated.

 

The numbers on this map are wind gusts from the storm…in red those were measured gusts, in tan, they were estimated wind gust speeds. I would be surprised if we saw an event of that intensity (130 mph wind gusts in Grand Haven and Walker) and widespread area again in my lifetime. Here’s pictures from Grand Haven after the storm.

Here’s a regional view of the composite radar of the derecho of 1998

A final note…. In 1998, there were four major derechos across the Great Lakes states…this one was the worst. Storm Team 8 will be tracking storms this summer. We’ve had a pretty quiet spring for severe weather in Mich

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