Weathercatch: Washington state’s biggest wildfire: Human caused, weather spread

A human is to blame for starting Washington state’s largest wildfire, burning since July 23.

When a hiker reported a blaze that morning, it had only consumed a few acres in the Pasayten Wilderness in Okanogan County. Had weather conditions been different, the fire might have fizzled. Instead, it took off.

First was the fact that it hadn’t rained since June 16. By July 23, lack of precipitation and a spate of hot temperatures had made surrounding trees vulnerable to ignition. To make matters worse, wind gusts of 21 mph moved in late that afternoon, quickly pushing flames into an all-out wildfire.

To date, the Diamond Creek fire has raged through nearly 48,000 acres of mostly dry spruce and pine trees. And though fire crews have the blaze 63 percent contained, full containment is not expected until mid-October.

Located in northcentral Washington, 12 miles from Mazama, the fire has been accelerated by a host of weather conditions: direct sunlight, high temperatures, wind and breeziness, unstable air and low relative humidity.

Basically, it’s a wildfire devouring nearly bone-dry trees in steep terrain. It gains the most momentum on hot days that are windy or breezy. Not surprisingly, when temperatures broke 100 degrees during the second week of August, flames traveled fast and far.

As you can imagine, the incident commanders, smokejumpers and hotshot crews pay careful attention to current weather conditions and those forecasted.

Unfortunately, they won’t be happy about this week’s outlook. Cooler temperatures expected on Thursday will be accompanied by increased winds. Then a major heatwave should follow – just in time for the Labor Day weekend.