I know I speak for us all in hoping for a tamer fire season this year. Long-range forecasts are always very tricky, but we’re now close enough to summer that we have some guidance on how the 2019 summer might turn out. Let’s take a look.
The three biggest factors meteorologists look at when making a seasonal fire forecast are the amount of fuel for fires, the moisture content of this fuel, and the weather conditions themselves (which both determine the former two and provide for periods of enhanced/diminished fire danger).
Counterintuitively, a wet spring actually increases summertime wildfire danger, and this is because wet springs create more vegetation that can be burned in the summer. The summers east of the Cascades (where most of our fires occur) are plenty hot and dry enough to create tinder-dry fuels, so springtime fuel moisture content is not nearly as correlated to summertime fire danger as fuel availability is.
This winter and spring were drier than average, which limited the amount of new undergrowth. Unfortunately, it also means that soil and fuel moisture levels are below normal for this time of the year, especially with the record-breaking heat we saw during the second week of May. A weak El Niño is still brewing in the Pacific, and these El Niños tend to bring us warmer than average weather for at least the first half of summer. So unfortunately, current forecasts point toward another smoky summer. Let’s hope it’s not as bad as the past two.
Smokier Summers: A Trend?
There has been a clear increase in wildfires over the past decade, and the causes are multi-factorial. The biggest cause of this increase is that, due to decades of fire suppression and poor forest management practices, the forests of Eastern Washington and Oregon are abnormally thick, allowing fires to grow far larger than they did in the past when forests were thinner. Additionally, more people live, work and recreate out in fire country now, and human-caused fires are becoming a more regular occurrence. Finally, the past several summers in particular have been extremely hot—more so than can be explained by global warming alone—but global warming is undoubtedly having an effect by prolonging our summers and decreasing fuel moisture.
So yes, we’ll likely be in for yet another more active-than-normal fire season in the Pacific Northwest. I don’t think we’ll be as smoky as the last two years (2017 and 2018 had ash falling from the sky, after all!), but I unfortunately think we’ll see some smoky periods with poor air quality. As always, obey all fire laws and burn bans: during hot summer days, all it takes is a spark to create a raging forest fire.
On that note, have a wonderful, wonderful summer! Enjoy the sunshine, the lake, and everything that makes our Leschi summers so special.
Charlie Phillips, a Madrona resident, received his B.S. in atmospheric sciences from the University of Washington and works in Portland as a meteorologist. Check out his weather website at to charlie.weathertogether.net.