By Bob Berwyn, Inside Climate News

When he saw smoke in the air around Boulder, Colorado on Dec. 30, Tom Veblen walked up a trail near his home to check it out. Veblen, a professor emeritus of geography at the University of Colorado Boulder who has been studying forest ecology, wildfires and climate change since the mid-1970s, said he could see that the Marshall Fire, on the southern edge of the city, was already jumping over distances of several hundred yards.

The winds were so strong that he said he struggled to open his car door, and to stay on his feet in the powerful gusts. Wooden fences separating yards in the suburbs sprawling in the distance looked like burning fuses, as winds gusting faster than 100 mph pushed the flames along them to ignite decks, roofs and residential landscaping. The firestorm would eventually engulf shopping malls and a hotel.

As a resident of a neighborhood he had previously believed to be a safe distance from the fire-prone forests, Veblen felt a sudden and unfamiliar sense of vulnerability.

“Sure, I knew that Chinook winds could drive winter grassland fires to spread very rapidly, but in the past we just did not have all the driving factors align so perfectly—wet spring producing abundant grass fuels, one of the warmest and driest June-Decembers on record and then an ignition at the base of the mountains.” Local topography also contributed to the intensity, with a canyon opposite the fire acting like a nozzle, blasting  winds from the peaks onto the flames and pushing the fire east into suburban neighborhoods.