Southwest Colorado may finally receive desperately needed rain this weekend, but it could come at a cost: a flash-flood watch has been issued for Saturday.
The National Weather Service in Grand Junction issued the warning Thursday, saying the flash-flood watch is in effect from 9 a.m. Saturday to 12:01 a.m. Sunday.
Areas include the Animas River Basin, the southwest San Juan Mountains and the U.S. Highway 550 corridor, including Durango and Hermosa. This includes burn areas from the 416 and Burro fires, the Weather Service said.
During this time period, flash flooding from heavy rainfall is possible, especially over burn scars and areas of steep terrain. This may result in rock and mudslides, as well as high water flowing across roads.
The Weather Service said heavy rainfall over the burn scar from the 416 Fire is of particular concern.
“Residents near this wildfire and along the Highway 550 corridor near Hermosa should prepare for potential flooding impacts,” the Weather Service said.
Mike Charnick, a meteorologist with the Weather Service in Grand Junction, said Durango and the area of the two active fires could receive up to an inch of rain Saturday.
The chance of on-and-off precipitation remains Sunday, but the best chance for rain and flooding is Saturday, he said.
When heavy rains fall on recently burned land, the chance for flooding and landslides significantly increases.
Usually, soils and vegetation can absorb rains, reducing runoff. But wildfires scar the land and leave soils burned and unable to retain water, thereby increasing the risk of flash floods and landslides.
“And it doesn’t take a whole lot of rainfall to do that,” Charnick said.
Even areas that haven’t been burned are at risk of flooding. Charnick said because of the extreme drought, soils unaffected by the fires can be too dry to absorb water.
Cameron Beck, a spokeswoman for the 416 Fire, said because the region has been in such a prolonged and extreme drought, it would take a significant amount of rainfall to dampen the active fires.
Firefighters will carry out their operations as planned over the weekend and assess the impacts of the rains in real time.
Beck said associated mudslides could affect access to fighting the fire.
The predicted rains are a result of Hurricane Bud, a tropical storm off Mexico’s Pacific coast.
In the meantime, Southwest Colorado will face extremely dry and hot conditions.
The Weather Service issued a red-flag warning from Thursday through Friday afternoon. Winds gusts could reach up to 40 mph, and there’s a chance for isolated dry thunderstorms.
The next chance for precipitation past this weekend, the Weather Service says, is Wednesday.
jromeo@durangoherald.com
