Stories tagged undular bore

Oct
14
2007

Fitting that something called a "bore" would be found in Iowa: Photo by NASA.  Minnesota trash-talk by Gene
Fitting that something called a "bore" would be found in Iowa: Photo by NASA. Minnesota trash-talk by Gene

Colliding masses of air over Des Moines, Iowa on October 3 formed waves of clouds known as an undular bore. (Time-lapse video at the link.)

What happened was an approaching thunderstorm plowed into a mass of stable, cold air, like the prow of a ship plowing through the water. This set up huge waves in the air, which rippled over Des Moines. Winds would whip around 180° as the waves rolled by.

Scientists think these types of waves may be more common than we know, and may play a big role in violent weather.