By CHRISTOPHER SMITH
The Associated Press
BOISE, Idaho - Wildfire experts have come across a seeming contradiction this summer: While the number of acres charred across the western U.S. is almost double the 10-year average, the blazes haven’t been as big or devastating as those in past years.
Experts say that’s due to the unusual moisture patterns in the region earlier this year, which favored big grass fires on the open range. Timber in the mountains got more moisture than usual well into the summer, keeping forest fires small.
And fate has played a role.
''It’s sort of like Swiss cheese. All the holes have not lined up at the same time,’' said Tom Wordell, a wildland fire analyst for the U.S. Forest Service and leader of the multiagency group of scientists and meteorologists that predicts fire danger around the nation.
''To get a big fire, you need high temperatures, low relative humidity, dry fuels and winds all aligned on the same day,’' said Wordell. ''We haven’t seen that much this year, yet our overall acreage burned is much higher than in the past.’'
According to the National Interagency Fire Center, over 7.8 million acres (3.1 million hectares) _ more than 11,000 square miles (28,160 square kilometers) - have burned in the U.S. since May. About half of that was in Alaska, where large fires often are not fought aggressively if they pose no threat to people or structures.
With the 2005 wildfire season two-thirds over, the number of fires is down _ about 46,000 compared to the 10-year average of 63,000 - and the number of firefighters suppressing the blazes has been lower than in recent years. Yet the total acreage burned is nearly double the 4 million acres (1.6 million hectares) that burned on average through late August over the past decade.