Monday, June 14, 2021
Friday, October 9, 2020
As always, good news first
Wildfires in WA and most of OR are out and there is no risk of returning to the terrible conditions we endured last month. Fall meteorology is active enough to keep air moving along and prevent a buildup of pollutants.
What to watch for
- Northern CA fires are still burning and an occasional whiff of smoke is still possible. Western WA got a small dose earlier this week, causing Moderate air in some areas.
- Wintertime wood smoke season is coming and while it almost never gets as bad as what we've just been through, temperature inversions and light winds can cause smoke to stagnate. Valley communities are more prone to this and often experience poor air.
- Check if an air quality burn ban has been called for your area (not to be confused with fire safety burn bans).
- We recommend our readers keep an eye on the map at the top of this page. It is automatically updated with measured fine particle pollution data and a two-day forecast, year round.
- This blog also contains resources on how to safeguard your health during polluted periods.
See you in summer 2021!
Thursday, October 1, 2020
Smoke continues to hover overhead and the previous forecast still holds. As explained there the temperature inversion is still keeping the smoke at bay. We've hardly seen air quality deteriorating beyond Moderate anywhere in the state, or further upwind in Oregon for that matter.
There is fog in the Puget Sound lowlands and this will recur each morning through Sunday. Fog should not be confused with smoke. Here's an illustration of what's what as seen from above, but only an air quality monitor can distinguish between the two at ground level.
Things will stay that way and start to "improve" by Saturday night as a slight wind shift s-l-o-w-l-y disconnects us from the CA smoke late in the weekend. Models are persisting with the inversion in western WA so any residual smoke aloft wont mix down all that much. But inversions also lock in our own local emissions at the surface. Overall, we can expect:
- Good to Moderate air in much of the state
- Moderate or areas of Unhealthy for Sensitive Groups in the higher terrain of the Olympics and Cascades (hard to pin down what elevation the transition occurs).
- Saturday's sunset may not be as colorful
BTW the air quality monitoring data map at the top of this blog has been upgraded to show both the new EPA Fire/ Smoke map that incorporates corrected low-cost sensor data, and our 2-day PM2.5 forecast. Might take a moment to load. If you're using a mobile device, scroll to the bottom of this page and click "View web version" to see this.
Tuesday, September 29, 2020
There has been some speculation that another bout of Californian smoke will overrun western WA again this week. Thankfully, it now seems like those concerns are a bit overblown.
- Starting Tuesday evening, there will be a little smoke in western WA. Not expecting populated areas to get worse than Unhealthy for Sensitive Groups, although Moderate will be the most common.
- Higher elevations will see more smoke.
- This will not be a prolonged event. Please keep an eye on the smoke forecast.
- Get ready to enjoy some resplendent sunsets
- Hardly any impacts expected east of the Cascades
What does the latest satellite picture (10:20AM today) look like?
Smoke is indeed traveling northbound along the Oregon coast now.
What do the models say?
They have their own opinions, some with more merit than others. Discussing with the National Weather Service offices and air quality agencies, we feel that the HRRR smoke model injected too much smoke into the air and is trying to offload a generous portion of that in our backyard. We're not buying it. Most other models are (i) working with less smoke and (ii) keeping a lot of it aloft. This is consistent with satellite imagery, ground based air quality monitoring data and the vertical temperature structure of several models.
Here's what different models think the mixing heights in Olympia will be for the next 72 hours. Black line is the mean of them all.
This means vertical mixing through the atmosphere is confined to a shallow layer, ~400m today at most, 700m max tomorrow and back to about 400m on Thursday. Most of the smoke will be 1-3km above us, so we won't be tapping into the overhead smoke reservoir all that much.
This is a good example of a temperature inversion working in our favor by not allowing smoke aloft to mix down. But inversions also trap pollutants released at the surface within a shallow layer, so we still have to deal with our own gunk in addition to whatever little smoke mixes down.
Will the smoke aloft interfere with Aurora Borealis viewing?
Probably, but there needs to be a good aurora. We returned home disappointed at 2AM this morning and tonight's geomagnetic activity is expected to be no different than yesterday. If a faint glow does appear low on the northern horizon, the smoke will filter some of it out. Going to higher terrain won't help much.
Wednesday, September 23, 2020
The record-shattering smoke storm of 2020 is now behind us. Rain clouds have replaced the choking fog of smoke that held Washington in a vice for more than a week, and the annual dread of late-summer wildfires appears to have eased.
As the smoke lingered, hundreds of questions poured in to the Washington Smoke Information blog, where Dhammapala and fellow smoke forecaster Farren Herron-Thorpe tried to provide updated forecasts, explanations, and advice. More than 2.5 million people visited the smoke blog over the week, while another 2.6 million looked to Ecology’s air quality monitoring map for the latest conditions.
Monday, September 21, 2020
No doubt everyone breathed easy yesterday when air quality in the whole state returned to Good. How long will it stay that way?
The map of monitors above shows Moderate or Unhealthy for Sensitive Groups air at several locations in Clark, Klickitat and southern Yakima counties. These are due to smoldering fires nearby. Even though fires are not puffing smoke like they were, low- buoyancy plumes are still draining some smoke into nearby cities.
These kind of relatively low grade and relatively localized impacts will continue on and off through late Tuesday. "Low grade" compared to last week, that is. A weak system tonight won't help a whole lot but a strong, wet front early Wednesday will show the smoke who's boss and knock back the fires. Impressive 24-hour total precipitation ending 5PM Wednesday, as per the average of all ensemble models at UW.
Two weaker storm systems are expected Thursday and Friday, bringing more good news to smoke- weary Washingtonians. However calmer, dryer conditions under high pressure are possible Sunday onward so lets not pop the champagne cork yet.
Friday, September 18, 2020
The Olympic Peninsula has pretty much cleared out now, and several Puget Sound area sites are trending downward. Rain is helping a bit, but the weakening inversion is helping most. Still on track to see mostly Good to Moderate air in western WA by tomorrow.
Just for kicks, take a look at how some sites in the Olympic Peninsula responded yesterday when a low pressure system offshore initially helped ventilate the area and then dragged in smoke from Oregon fires. Who said smoke dynamics aren't complex!
Population exposed to smoke (written by Ecology's Andrew Wineke)
As an agency dedicated to protecting air quality in our state, we’ve been trying to wrap our minds around not just what the numbers are this hour, but what the longer impacts of this kind of smoke storm may be.
As we’ve moved from one record-poor air quality day to the next, we’ve shared some charts and analyses as we work through those questions. One important takeaway is that more Washington communities have been exposed to more hazardous levels of particulate pollution than we’ve ever seen since we began monitoring for PM2.5 (the most concerning type of particulate pollution found in wildfire smoke) back in the early 2000s.
Geographic extent is just one way to look at it, though. Sometimes, we have quite serious wildfires that don’t affect many people – either because of helpful weather patterns that blow the smoke away, or simply because they are burning in thinly populated regions.
Ecology researcher Beth Friedman looked at how many Washingtonians have been exposed to extended periods of unhealthy air, compared to other recent smoke events. Looking at the smoke exposures this way helps us contrast this year’s smoke storm with other major events like 2018, where smoke from Canadian wildfires bathed much of our state with a longer period of less-intense air pollution.
So how does 2020 measure up when we account for populations in smoke- impacted areas? It may not surprise you that 2020 is a stinker: The number of people exposed to very unhealthy or worse air quality for a week or more is practically off the charts compared to 2018, 2017, or 2015.
Or if you want to include the Unhealthy category in the comparison:
Clearly, this has been an incredibly bad week for Washington’s biggest cities – and it hasn’t been a walk in the park for our less populated areas, either.
Thursday, September 17, 2020
So when will it be over?
Western WA: Early Saturday
Eastern WA: Saturday night
Why so long?
Western WA: Encouraging reductions at Olympic Peninsula monitors today and smaller improvements since yesterday in the Puget Sound lowlands. But strong winds off the Pacific are MIA so we have take what the lighter, shifty winds with a little rain (minions!) dish out. These minions are bringing disorganized, mixed results. Some smoke from Oregon fires are now being transported to western WA due to a wind shift, and even though a lot of that smoke is still aloft, it delays the already slow scrubbing process. Expecting Good to Moderate air in much of western WA by Saturday.
However Clark county and the Columbia River Gorge might continue to see Very Unhealthy air through tomorrow at least because of the proximity to fires, and their relief will be later on Saturday.
Eastern WA: The last 3 runs of the more pessimistic models have continued to show good ventilation across the Columbia Basin on Saturday, so there is good confidence this wont be a busted forecast. This will not immediately erode away all the smoke stuck in valleys, so it needs some time to do it's thing. By Sunday morning most of the air should be Good to Moderate, except very close to fires.
So how bad did it get?
Some of our readers asked to see a comparison of the # of successive days we were exposed to Very Unhealthy or Hazardous air. Dr Beth Friedman constructed the following plot to answer this question.
All of 2020's days were from the last week or so. Sadly this wasn't the worst run of bad air for our friends in Chelan and Okanogan counties.
Note: Monitors did not operate during all of the last 3 years are in the following 3 counties, and they are not included in the above plot. Their stretch of bad days was:
P.S. Don't throw open your windows to air out the house the moment air quality improves. With these minions around, it is best to wait a few hours to be sure there is a sustained improvement.
As our coastal sites turn green this morning and we start to see hope for clean air for the rest of us later today and tomorrow, I thought I’d take a minute to clarify some common misconceptions regarding air quality numbers, where they come from and what they mean to you. The two indices, Air Quality Index (AQI) vs. Washington Air Quality Advisory (WAQA), have created a lot of confusion.
Both AQI and WAQA are a unitless index calculated from a given concentration of air pollution. There are several different measured pollutants that affect air quality: PM2.5, ozone, NOx, CO, and SO2. PM2.5 is the most commonly measured and generally the one of most concern in Washington state, especially during wildfire smoke episodes. Although all these pollutants can affect AQI and WAQA values, I’m only going to focus on PM2.5 in this post.
State and Federal government run air quality maps (https://airnow.gov and https://enviwa.ecology.wa.gov/home/map use the same air quality monitors and data to determine air quality in your area, but they use a different index to represent what that air quality means for your health.
So, why are there two different indices? Although we assign breakpoints to the different categories, air quality is a spectrum. Every person will be affected by poor air quality differently. These are general guidelines and the breakpoints are based on statistical assessments of how large numbers of people respond to varying levels of poor air quality. EPA studies have assigned risk at a certain point, while Washington state toxicology research found more protective levels would better serve our community. Looking at the breakpoints in this table, a PM2.5 concentration equal to 50 ug/m3 is considered unhealthy by WAQA standards, but unhealthy for sensitive groups when using the AQI scale. You are not a statistic and may be adversely affected at moderate levels, or perhaps you can go hiking without difficulty when conditions are unhealthy for sensitive groups. For individual health concerns, your best bet is to consult your doctor.
AQI and WAQA health risk categories are based on a 24-hour exposure. The number you see on the map is updated hourly and represents the previous hourly average weighted by the air quality observed over several hours before. For example, if the air quality is green all morning and a nearby building catches on fire, smoke may affect the monitor for one or two hours at unhealthy (red) levels, before returning to green. The monitor may only show unhealthy for sensitive groups (orange) during those two hours since the exposure time was so short. As we observed at the beginning of this smoke event, heavy smoke rolled into some areas very quickly and air quality went from good to hazardous in 30 minutes. The map will not update that value until the hour of data collection is complete and may take another hour or two to catch up to instantaneous air quality. Both airnow and the state maps have the option to look at the actual hourly PM2.5 concentration from the previous hour. Those numbers will be the same on both maps.
The second question we often get is “who is more trustworthy? My air quality app, a third-party air quality reporting site, airnow, or the state air quality map”? It is important to understand all these sites are using the same data, if they are using actual air quality measurements. We don’t often know how third-party apps and websites calculate the AQI or interpret our data. In that sense, we consider EPA and the state map to be the gold standard as we are directly involved in collecting the data, making sure it’s valid, and reporting the concentrations.
Wednesday, September 16, 2020
There are claims that we've been exposed to the worst air in the world. True? Fair comparison? Let's investigate that without belittling the terrible air quality conditions we've all had to endure for at least a week now.
Here's a map of global air quality right now. It uses all available measurements worldwide and uses machine learning methods for spatially interpolation. US west coast is in baaad shape. Worst ranked cities right now are all in our neck of the woods.
The above figure shows how air quality in Seattle, Spokane, Vancouver, Omak and Yakima have varied from 1 Jan- 15 Sept 2020, against the backdrop of IQRs at ten embassies. As can be seen, the overseas cities experience terribly compromised air quality primarily in the winter months. Right now is their "better" season. Even though we spiked right to the top of the AQI chart this week, bear in mind that:
- All these overseas locations see concentrations that are higher than their own IQRs 25% of the time. Or put another way, they record even higher concentrations for 3 months of the year.
- Our air will not remain this bad for several months. Most WA sites have experienced some improvement already and we're still on track to clear out in the Friday- Saturday timeframe.
- In spite of our wintertime temperature inversions and woodsmoke concerns, we're still in far better shape at that time of year.
Moral of the story: yes its bad here now. Many others have it worse for much longer. Folks who live in these environments and our diplomats serving there can offer us some coping tips.