Chances of rain across western Montana are increasing through Wednesday, with the possibility of downpours in isolated areas. This of course brings up the possibility of flash flooding in areas that will see large amounts of rain.
In areas with steep hillsides or burned by wildfires, a flash flood can occur with only 1/4 of an inch of rainfall. For Western Montana 1/4 of an inch is a considerable amount; but tomorrow promises to bring totals near an inch of rainfall to some areas.
According to National Weather Service Meteorologist Ryan Leach, the main concern for flash flooding will be along the Salmon River in Idaho. The burn scar from the Mustang Complex Fire, over 300,000 acres, will have the potential to cause mudslides loaded with dangerous debris such as rocks and trees.
A Flash Flood Watch is up as of 5:00 PM Tuesday for Lemhi and Idaho Counties in Idaho as well as Yellowstone National Park. A heavy thunderstorm over an active fire may even have the potential to send smoldering timber down mountainsides. Thunderstorms are double-edged swords for fire crews. They bring beneficial rain, but also lightning, strong winds, and of course the flash flooding threat.
Of all severe weather related events, flooding is the number one killer. Here are some simple tips to avoid danger in a flash flood situation.
Most issues from flash flooding come when people are on the roadways. If you are driving and come across a flooded roadway, do not attempt to drive through it. It only takes two feet of floodwater to sweep your car off the road. If you live in an area prone to flash flooding, be prepared to move to higher ground if necessary if a Flash Flood Warning is issued for your area.
The bout of heavy rain is expected to end late Wednesday; making way for another round of blistering heat. For more information on flash flood safety, visit the National Weather Service "Turn Around Don't Drown" campaign site here.