KMSP - Hundreds of thousands of acres of land have burned, thousands of homes and businesses have been destroyed, and it was just the wettest water year on record in California. Not exactly what one would expect. While Napa, Sonoma, and several other communities have dealt with countless fires over the last few weeks, it comes after the state experiences one of the wettest years on record. But for the Sierra, it was the wettest water year ever.
A water year is a lot like a fiscal year for a company. You have the normal calendar year that goes from January to December, but often times companies have fiscal years that can be much different from a calendar one. Well, in the weather world, the water year is no different. The water year goes from October 1 to September 30th to try to keep any and all snow totals into one year. This helps the climate data be more accurate because many areas will receive snow that doesn’t actually melt and make it into river basins and reservoirs until spring which can have implications on the following year. To account for that, the water year is offset by a couple of months.
So if California experienced such a wet year, how can the fires be so bad? Well, that heavy rainfall can actually create more fires. California is a Mediterranean climate. This climate distinction means the area is fairly mild but has distinct wet and dry seasons. This past winter and spring was extremely wet, leading to increased runoff, higher reservoirs, and an abundance of vegetation growth. But then the rains stop, almost completely for several months which means all of that abundant growth is now extremely dry. All it takes then is a spark and that vegetation goes up in flames. And with more of it around because of the extremely wet winter and spring, it can often spread faster and become hotter IF a fire is started.
Unfortunately for Californians, this will never change. There will always be a wet and dry season in the state. But the continued increase in population will likely put more people at risk from fires because more people are living in high fire prone areas. Not to mention, the majority of fires are sparked by humans, and with more humans around, more fires are likely to ignite.