Typically a derecho contains multiple microbursts, downbursts and downburst clusters.
Buttrick said the weather service was not able to measure the severity of the winds in those towns, but it appeared to be from a downburst, a larger-scale microburst.
The study finds that downbursts
are dangerous to navigation.
A bizarre wind - perhaps a storm-related phenomenon called a downburst - came out of nowhere Wednesday and briefly whipped through an interior courtyard garden at South Eugene High School, lifting a wooden bench into the air, bending a metal awning and sending students, a teacher and a Register-Guard reporter there on an unrelated assignment diving for cover.
As there was no visible funnel cloud, he said it was more likely a downburst than a small tornado - though he said it sounded like an un usually strong wind.
Downbursts - out-rushing air from thunderstorms that slam into the ground and can exceed 100 mph - can do plenty of damage.
Several years ago, while he was on a training outing near Oakridge, a downburst ripped a 20-by 20-foot tent off the ground.
Supercells also bring dangerous lightning, as hot as the sun; can produce hail as large as softballs (sometimes called the "white plague") that harm people and property; and often cause damage from powerful winds known as downbursts
These wind events include hurricanes, tornadoes and downbursts
dating back to Hurricane Alicia and most recently at the Oklahoma City tornado.
With new weather radar, the system looks for downbursts
of air which indicate windshear conditions that the airplane might encounter when landing or taking off.