Derecho struck wide swath of Iowa 23 years ago
CEDAR RAPIDS, Iowa (KCRG) - Many people in Iowa learned the term “derecho” on August 10, 2020, but parts of the state experienced one of the same very damaging wind storms in the late 1990s.
In an event that is sometimes referred to as the “corn belt derecho,” a complex of thunderstorms developed in northwest Iowa, southeast South Dakota, and northeast Nebraska during the morning hours on June 29, 1998. The storms, initially supercells that produced large hail and isolated tornadoes, eventually organized into a damaging bow echo, diving southeast toward the Des Moines area in the early afternoon.
The complex then turned east, moving parallel to Interstate 80 and maturing to produce frequent very intense wind gusts of 80 to 100 mph. An observer in Muscatine recorded a 104 mph gust, and an unofficial wind gust of 123 mph took place in Washington. At the time, that held the record for strongest wind gust speed in the state’s recorded history. In addition, severe wind gusts in the Iowa City area lasted at least 20 minutes, a condition that was repeated in many areas of eastern Iowa during the August 10 derecho.
The storms turned further southeast as they crossed the Mississippi River, continuing to produce severe winds as far as northern Kentucky.
Damage was widespread in the Des Moines area, with estimated losses of around $100 million in just Polk County. Significant damage took place there to homes and trees, with semi-trucks overturned on Interstate 35 and Interstate 80.
Iowa City was another area particularly hard hit, with damage in Johnson County adding up to $30.7 million. Trees and homes sustained damage, and the winds were strong enough to blow a freight train off of its tracks on the Iowa Interstate Railroad, leaving cars dangling into the Iowa River (as seen by NewsCopter9 below):
Crop losses were significant in affected areas, with some spots seeing up to 75% of the crop wiped out by the strong winds. Power outages were widespread and long-lasting, with around 500,000 customers out at their peak and some waiting up to a week for restoration of service.
One woman was killed near Columbus Junction in Louisa County when she left her car to run for cover, getting hit by a falling tree. 159 people were injured across the state in that day’s storms. Property damage included 80 homes destroyed in Iowa, 559 with severe damage, and 1416 homes receiving at least moderate damage.
Fortunately, storm complexes, and even derechos, of this intensity are fairly rare. This storm was not surpassed in its intensity and widespread nature in the state until 22 years later, on August 10 of last year.
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