Heavy Smoke & Very Unhealthy Air Quality In Western Washington

Very unhealthy air quality is being observed across Western Washington due to heavy smoke from Oregon fires.  

I took this photo as the sun was setting tonight. I was outside for less than 2 minutes, but you can smell and feel the smoke. It's as if the air is "heavier" due to the smoke.

Let's take a look at Puyallup's 7 PM air quality on the EPA AirNow app.

This is very unhealthy air quality (201-300). At this point, it is hazardous to be outside, and staying indoors is highly recommended. In comparison, the most recent smoke event (August 2018) had peak air quality of 190-200. We have beaten that by over 40 points already.

Air quality may be even worse in the valleys and near the Sumner Grade Fire. Air quality in Bonney Lake has been in the "hazardous" category today, due to even more smoke in that area. There is a chance that parts of our area could record "hazardous" air quality between now and Sunday, depending on how thick the smoke is.

Here's the EPA's definitions of the air quality index (AQI).

Notice that we are in the 4th out of 5 categories (very unhealthy). Being outside is not recommended, and if you can do something inside, that is your best bet, especially if you are a sensitive group. This includes kids, teens, the elderly, and those with underlying conditions. You can even feel the effects of the very unhealthy air quality when you're inside. I have had a mild headache all day, due to the degraded air quality.

Remember, you can check air quality on your mobile device by downloading the EPA AirNow app on the App Store or Google Play Store, and you can check air quality on your computer at this link: https://www.airnow.gov/state/?name=washington

An Air Quality Alert is in effect for Western Washington until 11 AM Monday. The alert is below.

There's some strong words and good recommendations in this alert. You can find more information about how smoke impacts your health here: https://www.epa.gov/pm-pollution/how-smoke-fires-can-affect-your-health

Today's smoke was thick enough to significantly limit solar radiation. Here is the graph of observed solar radiation in Federal Way.

That's a big difference. If it felt darker outside to you today, it was...even though yesterday's radiation was impacted by smoke as well. The temperature only reached the mid-70s today as well, which shows the impact of the smoke.

Now for the forecast...the general trend is that smoke will continue through Sunday. Relief is likely on Monday, though it won't completely remove the smoke. Let's break it down.

Here is the forecast for near surface smoke at 11 PM Friday.

Very thick smoke over nearly all of Washington. It will likely be even worse by Saturday morning, due to the fact that smoke settles at night due to light winds, and we have a temperature inversion right now.

Here is a graphic of a temperature inversion. In our case, clouds and the inversion layer are pushing the smoke down to the surface, degrading air quality. This image can be found here.

Back to the forecast...below is the near surface smoke at 9 AM Saturday.

That is very dense smoke in nearly all of our state except the North Central Cascades. Expect Saturday to be another day of unhealthy-very unhealthy, and possibly hazardous air quality. Notice the incredibly heavy smoke over nearly all of Oregon, parts of Eastern WA, California, and it's beginning to sneak into the Reno and Boise areas. Most of the Western US is being impacted by this smoke.

Here is 5 PM Saturday. Smoke is still quite heavy, and I don't expect much change in air quality.

After this, slow improvement is expected. Below is 8 AM Sunday. Notice the smoke is a bit less dense, with major improvement on the WA Coast and in Western OR.

At this time, it is still quite thick over Eastern WA, OR, and most of Idaho. Smoke will slowly improve through Sunday, though there will still be smoke aloft, and air quality will be on a slow rebound to healthy levels.

I will end with even more good news! Here is the UW Model rain forecast through the next week.

It is likely that most of the area will get 0.1-0.3 inches of rain, though these details are long range and may not be reliable. Just know that it is likely that we will have rain this week. 

Here is the bottom line: Try your best to stay inside this weekend. Smoke will persist and air quality will be very unhealthy. Slow improvement is likely Sunday.