DURANGO, Colo. -- At least 18 large wildfires burning in eight Western states have torched nearly 155,000 acres. Near Durango, Colorado, more than 1,000 firefighters are trying to control a drought-fueled fire in the San Juan National Forest.

As of Friday, the 416 Fire was only 18 percent contained, burning more than 32,000 acres in the last two weeks. Firefighters are trying to stay ahead of the flames, digging fire lines and laying hose in case gusty winds send embers flying.

The wildfires are moving quickly. When they pass through, it's a wave of flames 50 to 60 feet high -- sometimes over the tree line. Conditions are so volatile that if the winds shift, the fire could sweep through once again.

This weekend, a storm in the forecast could bring relief, but also new problems. With the remnants of post-tropical cyclone Bud moving in overnight, crews are worried about flash floods.

National Weather Service meteorologist Jeff Colson said areas with burned-out vegetation can become trouble spots in the rain.

"Sometimes it dams up and a lot of water will build up behind it," he said. "That will release and then we get that flash flood moving down the slope."

Crews are bringing in a hydrologist, which is a water expert, to try and pinpoint areas that could be prone to flash floods. A roadblock is still set up to keep people away from the flames, and some people are being let in temporarily, but only if their area is safe.