Credit: National Weather Service
National Weather Service map shows flood warning area
As of Friday, May 29, 2015
CARLTON The National Weather Service has issued a new flash flood watch for the Methow Valley, particularly in the area burned by last summer’s Carlton Complex fire.
The watch continues until 8 p.m. today.
Thunderstorms are expected to develop between 1 p.m. and 5 p.m. today. A few storms “could be strong, bringing the potential for heavy rainfall,” the service said.
Areas that burned in 2013 and 2014 will be the most susceptible to flash flooding and debris flows. Areas near or below steep drainages also will be at risk.
Besides areas burned in the Carlton Complex, those burned in the Chiwaukum Complex also could be affected.
The weather service said flash flooding and debris flows are very dangerous and people in the watch area should remain alert to changing weather conditions.
“It takes as little as 10 minutes of heavy rain to cause flash flooding and debris flows in and below areas affected by wildfires,” the National Weather Service said. “Rain runs off almost instantly from burned soils, causing creeks and drainages to flood at a much faster rate than normal.”
Soils in a burn scar can become unstable, sometimes resulting in debris flows and falling rock.
Additional threats from today’s expected thunderstorms include small hail and wind gusts up to 30-40 mph.
A low pressure system will move in over the region early next week, the service said. It will result in afternoon and evening thunderstorms across much of the region. The main threat will be heavy rain, although lightning with small hail and gusty winds are additional concerns.
A flash flood warning yesterday resulted in flooding in the Texas Creek area. No major damage was reported.