The video above is courtesy KEPR in Washington via CNN.
By Andreas Preuss
(CNN) -- A substance described as "white stuff" and "milky rain" is covering parts of Washington and Oregon states, but its origin is a mystery.
"We have received reports of 'white stuff' on vehicles. The ash is more than likely from the Volcano Shiveluch," Washington state's Walla Walla County Emergency officials said in statement.
The volcano, located on the Kamchatka peninsula in extreme northeast Russia, "spewed an ash plume to about the 20,000-foot level in late January," the agency says. "It has been deposited in a widespread area, including Washington and Oregon."
But in an updated post, emergency officials say it could be as a result of various reasons.
"While the substance is likely ash is from Volcano Shiveluch, they are a number of volcanoes that are currently active," they say. "The source of the material has not been scientifically confirmed."
And the ash may be from another part of the world.
"The strong southerly flow from the jet stream could have brought it from an active volcano in southwest Colima, Mexico. But if we go farther west towards eastern Russia, there's another active volcano there," says CNN Meteorologist Derek Van Dam. The Mexican volcano is near Guadalajara and erupted Wednesday.
The distances between the volcanoes and the Washington/Oregon areas are staggering -- the Russian volcano is 4,000 miles away and the volcano in Mexico is more than 2,000 miles away. But there are some other theories floating around.
"We have heard a few theories thus far including; volcanic ash from Mexico or Russia, dust picked up from last night's strong winds, or perhaps ash from last year's wildfires over SE Oregon/SW Idaho. We still don't have a definitive answer," the U.S. National Weather Service in Spokane posted on its Facebook page -- along with a picture of what it called "milky rain" collected from its rain gauge.
Van Dam says the only way to be sure is to conduct scientific testing on the substance. Its chemical makeup would be the best clue to solving the mystery.
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