"Dirty rain" fell in Washington state, Oregon and Idaho on Friday, according to Discovery News. Even the National Weather Service (NWS) thought it was weird enough to send away for analysis.
NWS thought at first the milky rain was due to gray-colored dust from a storm in Nevada. The Walla Walla County, Wash. emergency management agency said on its Facebook, "The ash is more than likely from Volcano Shiveluch in Kamchatka Krai, Russia, which spewed an ash plume to about the 22,000-foot level in late January. It has been deposited in a wide spread area, including Washington and Oregon." Volcano Shiveluch is about 4,000 miles away from the area of the odd phenomenon.
CNN meteorologist Derek Van Dam offered another reason for the white stuff: "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."
The volcano in Mexico erupted on Wednesday.
"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.
