The Coming Fire Season

Post date: Jun 24, 2017 8:21:22 PM

There are two canonical answers to the question what will the upcoming fire season be like, either ask me again in December or the worst ever. In the 1970’s fire season in California averaged 78 days; according to A. Leroy Westerling of UC Merced and his collaborators, it is now more than twice as long. As we saw in 2014-2016, some years fire season doesn’t end at all. The sobering statistics of the last 25 years show that on a California, US, or global scale, on average fire seasons are growing exponentially longer and fiercer. As on June 24, 2017, when I am writing this, CAL FIRE has recorded 107 wildland fires in the State Responsibility Area; for the prior 5 years, the corresponding numbers are: 2016 – 48, 2015 – 37, 2014 – 48, 2013 – 58, and 2012 – 38.

At the top of our mountain today, the standard fuel moisture, a measure of the relative weight of wildland fuels to their dry weight, is hovering around 7%, which is the level that it was when the 2009 Lockheed Fire began. The observed fuel moisture of both live chamise at Saratoga Summit and of live manzantita in Corralitos are about average for late June, but dropping rapidly.