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'August Singularity' not just folklore

by JIM MANNThe Daily Inter Lake
| August 5, 2008 1:00 AM

Old fire dogs have talked about the "August Singularity" for years, firmly believing in a Northern Rockies weather phenomenon with powerful influences on wildfire behavior.

But recent research now has documented this firefighting folklore as an authentic meteorological event.

Conducted by Peter T. Soul/ from Appalachian State University in Boone, N.C., and Paul A. Knapp from the University of North Carolina Greensboro, the research was published in the June 2008 issue of the Journal of Applied Meteorology and Climatology by the American Meteorological Society.

"It has become a part of Montana folklore that the first major cold snap arrives in late August, but until now the existence of this event had not been scientifically established," states a press release from Appalachian State University. "The drop in temperatures associated with the August Singularity is triggered by strong midlatitude cyclones that occur across Western Montana and Northern Idaho in mid to late August."

Confirmation of the August Singularity was not surprising to Bob Sandman, a veteran incident commander on wildfires and currently the area manager for the Northwest Land Office of the Montana Department of Natural Resources and Conservation in Kalispell.

"I've heard that term used most of my career and I believe it's for real," Sandman said Friday, adding that the event is commonly expected by fire bosses in the Northern Rockies.

A singularity is a weather condition that tends to occur near a specific date more frequently than chance would indicate, according to the American Meteorological Society's Glossary of Meteorology.

The New England region's "January Thaw" that regularly occurs around Jan. 20-24 is the most extensively studied by far.

In the West, Sandman said, the most well-known and predictable weather event has long been the start of monsoon season that arrives in Arizona and New Mexico in June. But the August Singularity is not far behind.

Soul/ and Knapp studied data from the National Climatic Data Center recorded between 1900-2004. Focusing on daily data from early August to late October, they looked at deviations from normal maximum temperatures that were recorded at eight weather stations in Montana and Idaho.

They found that a significant cold spell in the Northern Rockies regularly occurs around Aug. 24-26. A shorter August Singularity also tends to occur around Aug. 13. Temperatures can drop by as much as 40 degrees below average during the event.

"Just about any fires I've been on during that time period, it's been both a curse and a blessing. It's rare that you don't get wind in front of a change in temperature," said Sandman, who was one of 17 elite Type I incident commanders in the nation. "On most of the fires I've been on it's been a challenge to deal with the explosive fire behavior that occurs … but if you're positioned to take advantage of the weather that follows, you're in a good position to get a handle on the fire."

Reporter Jim Mann may be reached at 758-4407 or by e-mail at