MESA COUNTY, Colo. Combine moisture, a steep slope and unstable geology and you have not only the cause of the most recent mudslide near Collbran, but also the conditions necessary for other mudslides to occur.
"You get to the point where the driving forces exceed the resisting forces," said Jonathan White, a geologist with the Colorado Geological Survey.
The National Weather Service can send out flood and thunderstorm warnings, but they can't predict mudslides because they don't know how stable the ground is.
"Very difficult to forecast," said Tom Renwick, a forecaster with the National Weather Service in Grand Junction. "We obviously had no idea here at the weather service, so yea these things are very unpredictable."
The more precipitation, the higher the risk of mudslides though.
"When you have a flash flood warning, that means a lot of rain is coming down, so the chances for a mudslide or landslide, if you're in an area that is conducive to that, chances are much greater that that might occur," Renwick said.
The Grand Mesa is prone to mudslides just like other steep areas of Mesa County like Mt. Garfield and the Uncompahgre Plateau.
Also, excessive snow runoff this spring and what's predicted to be a wetter summer than usual have increased the risk of mudslides.
"Obviously with more precip, the chance increases for more mudslides, more flash flooding, the monsoon may last longer so all of those may occur," Renwick said.