Last week a dusty rain coated cars and windows across eastern Washington, Oregon and north Idaho.
Theories of just where that ash or dust came from vary widely. Now, several groups intend to study what was in the rain.
A group of atmospheric scientists from the Pacific Northwest National Laboratory in Richland, Washington, intend to study the muddy rain this week. They have a theory that the sediment is ash from a Japanese volcano.
Another group that includes a University of Washington scientist and the Benton Clean Air Agency also intends to test samples. They think the sediment might be from a southeast Oregon lake, a recently burned area in Oregon or possibly even Nevada dust.
A Washington State University meteorologist weighed in with his analysis Tuesday. He also thinks the dust is probably from an ancient lake in Oregon.
The National Weather Service also has a sample, but says it won't test it. The agency posted a picture of a jar of cloudy water taken at the Spokane station on its social media sites.
Several scientists have made offers online to test material from the event, but a weather service spokesman said the sample was likely contaminated. He said it had been dumped into several non-sterile jars and that the whereabouts of the sloshy sample over this past weekend couldn’t be accounted for.