Some people have asked me about the threat of wildfires to our area this summer.
I have good news for them: Wet/cool spring and other factors make up a major wildfire season in Washington State abnormal. That means less low-level smoke and other impacts.
Why are people so worried? A major trigger is the irresponsible media, such as the Seattle Times.
For example, Seattle Times animator David Horsey published a recent cartoons showing Washington State on fire, with flames and smoke covering the entire state (see my performance of his cartoon below).
And ST David Horsey doesn’t stop there with awe:
“There’s a good chance that perfect August weather in Western Washington is covered in a thick layer of smoke blowing in from the fires north, east and south. “
As I will describe below, David Horsey and similar forerunners are ignoring science and data.
So let me explain why wildfires will be contained this summer in our area.
Reason 1: An unusually large layer of snow and ice.
We are talking more than 150% normal! (see below). The result is, The middle and upper slopes will thaw later than usual and the “fuel” will hold moisture well in the summer, which delays the start of the mountain bushfire season.
Reason 2: Spring is cold and wet
This is important. This year is very similar to 2011, the summer with very little local fire activity.
To get a sense of the situation, check below for the number of acres burned each year in Washington State over the past two decades.
There have been more fires in the last decade than there have been, which should come as no surprise to any of you. But consider carefully. There was one year that featured a lot of fires (2015) and another with almost none: 2011. Forests don’t differ from year to year – so what explains the large variation?
Below is a graph of the average temperatures for April and May for Washington State. 2011, the year with the fewest fires, had the coldest temperature to date! In contrast, 2015 was one of the warmest years.
What about spring rainfall (April-May)? 2011 had the wettest spring of this period, while 2015 was very, very dry.
All make sense. Cool, wet springs lead to fewer fires, and warm, dry springs lead to more fires. It is important that in both years the spring weather continues into the summer.
So what springs have we had this year?
Incredibly cool and wet like 2011. Of course, May isn’t over yet, but if we look at the last 60 days, the state has been a lot cooler than usual, especially the fire-prone east (see below). ).
Consider Wenatchee to the east of the Cascades and near the eastern Washington fire area. Between April 1 and May 23, Wenatchee “enjoyed” its wettest year since 2011 (see below)
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And Wenatchee this year was COLDER than 2011.
Seattle has its coldest year since 2011 (see below)
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Message to go home: spring temperatures/precipitation correlates with summer wildfire zones statewide, and this spring has brought conditions very similar (cool/wet) to those experienced in 2011 , there are very few forest fires in the summer.
Reason 3: Extended model forecast shows June colder than usual and normal rainfall.
Central Europe’s latest expansion forecast predicts cooler-than-normal periods through the end of June (see below, blue and green indicate below normal)
The total precipitation forecast for next month (below) is generally very normal (and slightly wetter than usual in western Washington). Besides, the upcoming Memorial Day weekend will be wet, with particularly large amounts in Oregon, where it needs to be.
Apparently, a cool, wet June has delayed fire season.
Reason 4: A strong La Nina summer
There is a significant impact of El Nino (warm tropical seas in the central/eastern Pacific) and La Nina (cool tropical waters) on eastern Pacific sea surface temperatures and weather in the region. our area. And another significant wildfire effect.
The figure below shows the exact index defining La Nina/El Nino for each three-month period since 2010. This is the Nino3.4 index, with large negative values (-.5 and below – in blue. ) is associated with La Nina and a larger positive value (+,5 or more red) with El Nino. Based on the latest observations and model predictions, I have come up with an expected value for this summer.
Note that the big fire year (2015) is associated with strong El Nino and the low fire year (2011) with La Nina. This makes a lot of sense: we tend to have cool and wet springs during La Nina years, with cool conditions extending into summer.
This summer there will be a La Nina stronger or stronger than 2011!
The La Nina years are associated with colder-than-normal waters in the northeast Pacific, and that’s exactly what’s going on now (see sea surface temperature anomalies…differences… do you see all the cold (blue) waters off our coasts?
Since air is moving eastward from the Pacific Ocean into our region, this implies a cooling effect for this summer.
Reason 5: Most of the endangered forests in our area have been burned
We’ve had a lot of fires in the last decade, because poor forest management over the past century has affected us. By putting out fires and allowing an unhealthy, dense forest to grow, we have created a litter box where large, catastrophic fires have occurred.
There is a lot of scientific literature that proves that a flame passing through an area can extinguish future fires for a decade or more. Therefore, with so much fuel burned during the past decade, there is less fuel available today. Here’s a fact that little media has talked about: fire makes it more likely to burn LESS in the short term.
A large portion of the area has already burned and is therefore less likely to burn today.
Reason 5: Fuel is abnormally wet
Fires need “fuel,” such as hay, felled or slashed trees, and the like. Moist fuel prevents or limits fires. And because of our cool, wet spring, the fuel in the nearby woods is unusually humid.
Consider 1000-hour dead fuels (tributaries and the like 3-8 inches in diameter) for the important eastern slopes of the Cascades and the Okanogan region to the north. When we had smoke in Seattle, the fires were generally in this area.
The graphic below is from the Northwest Fire Coordination Center. The values in red are the observed fuel moisture levels and the center line surrounded by gray is the average value. The top and bottom lines are the extreme values observed, and the gray area includes observations within two-thirds of the mean humidity.
Zone 6 covers the eastern slopes of the Washington Cascades and zone 8 is the Okanogan area. OH. Humidity in both areas is above normal … near record high. This thing won’t burn any time soon!
California smoke?
The situation in California is very different from that in the Northwest. They have been much drier than usual this past winter and so the CA fuel is thought to be able to ignite prematurely. There will be significant fires in the Golden State this summer, with the only good news being that a dry winter/spring will cause less grass to burn.
California fires rarely produce smoke in lowlands across Washington State, since any smoke that reaches us tends to stay overhead. We may have some haze, but little impact on air quality near the surface.
For lowland smoke to cover Washington, fires need to be near: over Washington or nearby areas of BC or Oregon.
California Smoke Moving North in 2018
Summary
Actual data and historical information on wildfires suggest a very benign local wildfire season in and near Washington State. Could we have a major fire if the meteorological conditions come together later this summer? It’s correct. But it is clear that the meteorological situation is not favorable for wildfires.
If everything goes as the data suggests, I hope Mr. Horsey and the Seattle Times will consider the following idea for an animated feature later this summer when the bleak future they predicted doesn’t materialize. realistic.
