A warm, stable airmass is stuck in place over Washington
Mid-level ridging is firmly entrenched over Washington for the next 5-7 days, providing warm temperatures, clear skies, and light winds for nearly the entire state. When we get patterns that have very little wind associated with them, daily wind patterns are dictated by terrain. In the afternoons, air heated along the mountain slopes tends to rise, yielding upslope winds. At night, the air more rapidly cools in the mountains and drains out through the valleys, yielding downslope winds. These downslope winds at night are the primarily driver for bringing low level smoke into the Puget Sound region, as well as into the Wenatchee Valley.
The "Omega Block" pattern is responsible for our warm and dry pattern with little wind this week
With very little wind outside of the daily upslope/downslope pattern, smoke can very easily get trapped in valleys and drainages. The worst smoke impacts through this weekend will be along Highway 2, spreading eastward from Skykomish, through Lake Wenatchee, and down slope all the way to the city of Wenatchee. Very concentrated smoke will also spread westward from Skykomish, down through Gold Bar and Monroe, with less intense but still impactful smoke for north King County and Snohomish County in the Puget Lowlands. Packwood will continue to see unhealthy levels of smoke from the Goat Rocks fire, and moderate to occasionally unhealthy smoke levels are possible in the Methow Valley from the fires in the North Cascades.
Morning satellite imagery shows fog in the Puget Lowlands, with dense smoke along Hwy's 2 & 12. More diffuse smoke is visible over the North Cascades
If you are wondering if this weather pattern is normal, it is decidedly NOT normal. Record high temperatures have been recorded at many locations across the state this week, with Seattle setting a record for most consecutive days above 75F for the month of October!
It is shocking that the federal government and the State of Washington have allowed the Cascade forest fires to burn for weeks on end. The air quality in the Wenatchee area has been unhealthy / very unhealthy since August. People, including myself, are experiencing significant health issues. This "let it burn" has got to stop. I have no doubt if these air pollution conditions were occurring in California, aircraft would have been brought in to put the fires out. Why the fires weren't extinguished when they were small is inexcusable.
Hello! I appreciate your comment and understand the immense burden prolonged wildfire smoke can place on a community. The Washington Department of Health has a tab at the top of this page with some guidance that hopefully can alleviate some of the hazard, but unfortunately smoke looks like it will be in the air for quite a while. In the Wenatchee area, you are seeing smoke from 3 different fires: White River, Irving Peak, and Bolt Creek. The first two were ignited by lightning in very challenging terrain in August, with Bolt Creek being ignited during our critical fire weather period in early September. The unfortunate reality of these fires burning in thick timber in difficult terrain is that firefighting strategies can only hope to contain the spread, it is up to mother nature to put the fire out for good. The water that can be delivered by plane is simply insufficient to extinguish such large fires without help from the weather, including cooler temperatures, cloud cover, and rainfall. The firefighters on these fires have put in enormous efforts to protect structures and prevent the fires from continuing to grow unchecked, unfortunately mother nature is not helping out with rain and cool weather.Delete
It feels like there is no end in sight here...air quality is remaining poor in Puget Sound. What will it take to really clear this out? The 10-day forecast is looking like basically no rain or cooling so will this entire month just be smoky?? I'm trying not to compare to the September 2020 smoke spell we had but it feels reminiscent.ReplyDelete
Sadly, most of us in the forecasting game agree with you. I wish I had more hopeful news, but there are no significant clearing systems predicted to come through the Puget Sound in the next several days.Delete
I do think the Puget Sound will see some relief Monday afternoon and Tuesday, but the same pattern we are seeing this week returns by next Wednesday. Unfortunately the long term forecast does not bring much hope.Delete
With regard to comparing to 2020, that depends greatly on where you are in the Puget Sound for this episode. Along US 2 close to Skykomish, such as Sultan, Gold Bar, Index, are actually at similar levels, and may end with more days than 2020. But further to the west, like western Snohomish, King, Pierce, and all of Kitsap, are seeing average pollution levels in the MODERATE range which is about 1/5 of what everybody had in 2020. Those further west along US 2 are in the middle, with Monroe being on the edge of UNHEALTHY FOR SENSITIVE GROUPS.Delete
For someone in average good health, what are the long-term health impacts of breathing even 'Moderate' AQI air for days on days on days on days on end?ReplyDelete
While there is a lot of evidence about short-term impacts of wildfire smoke on the order of days to a week, the long-term health impacts from wildfire smoke are not well known. This research is emerging after increasingly smoky summers. The categories of the AQI and the associated health risk, such as ‘Moderate’ or ‘Unhealthy for Sensitive Groups’ are based on a 24-hr exposure. Symptoms can range from minor (such as eye, nose, and throat irritation) to more serious (such as exacerbations of pre-existing conditions including lung and heart diseases), to an overall increase in hospitalizations and death. Most epidemiological studies of wildfire smoke investigate the relationship between a day’s smoke exposure and health effects that happen that day or up to about a week following that smoke day. These studies have generally found that there are impacts on that timeframe, especially among people in sensitive groups. The list of people with increased risk of health effects goes beyond people with health conditions and increasingly includes each of us, someone in our families, and our friends. While questions remain about long-term impacts of wildfire smoke exposure, it’s clear that breathing in smoke is not good for health at lower and lower PM2.5 levels. Do what you can to reduce your exposure.Delete
Appreciate the updates. It’s incredibly depressing being in Seattle, indoors, eyes burning and struggling to breathe (and this is with several air purifiers running).ReplyDelete
We know wildfire smoke is toxic and causes all kinds of health concerns, and we’re knowingly exposing a major metropolitan area to it with seemingly little interest in putting anything out. At some point, don’t we need something better than “let it burn until it doesn’t”? Or is moving the only solution?
I know I’m preaching to the choir and appreciate the opportunity to vent for a moment, as this is seriously impacting my life and the lives of my family. :(
Hey there! The Bolt Creek fire is responsible for most of the smoke in Seattle and Snohomish County, and it might not be much consolation, but large timber fires west of the Cascade crest are quite rare events. Usually by this time of the season we would have seen wetting rainfall on the fires in the Cascades, limiting the smoke production of the fires and eventually putting them out. Unfortunately, we are stuck in a more summer-like pattern for the next 7-10 days, with a brief period of relief likely for areas west of the Cascades on Monday evening and Tuesday. Firefighters have been hard at work since the day the fire ignited to contain the spread and limit the amount of timber the fire has access to burn.Delete
Our firefighting aircraft have performed significant work to help build the containment lines and suppress any new spot fires that start, but the scale of the fire is simply too large to be put out just through water drops. For reference, just 1 inch of rain on the area of the Bolt Creek fire (13,000 acres) is equivalent to dropping 353 million gallons of water on the fire...Mother nature can operate at scales that we simply cannot match.
I appreciate the response. Knowing someone’s listening is a consolation. Thank you.Delete
I have been scouring the Bolt Creek Fire updates page and while I understand some of the pro arguments (active fighting in those terrains would be too risky and not very efficient for fire fighters, letting it burn will reduce future risk, keeping vegetative structure intact to prevent landslides in the future)... there is a complete lack of gravity about the impacts of smoke on the population of Washington. We're just learning the insidious impact of poor air quality and how it can have incredibly noxious long and short term effects on exposed populations. It feels like the explanations pro consumptive strategy are giving the smoke kind of more of a nuisance value instead of a significant risk. I imagine in a usual year it would be the right strategy but I do wonder if we need to reevaluate teh trade offs involved.ReplyDelete
Thank you for these regular updates. I know it must be hard to not have good news as hard as it is for us to see that the smoke will continue.ReplyDelete
We were discussing at dinner last night - where do the "moderate" / "unhealthy for sensitive groups" / "unhealthy for all" labels come from? Are these based on short-term impacts, or do long-term impacts go into the consideration as well?
We have started thinking of smoke like we think of UV exposure - mitigate risk where we can. When it comes to UV exposure, there is guidance for what SPF to wear, etc. We are hoping to learn more in our household so we can make the same risk mitigation framework for smoke.
The AQI categories you see for PM2.5 (smoke) are based on EPA's prior review of health studies and are related to the 24-hour NAAQS. So, the messaging is intended to reflect a "daily" exposure to PM2.5. The annual standard is stricter, so if you experienced "moderate" PM2.5 for most of the year, it would be "unhealthy".Delete