Smoke Staying Near the Surface, Bad Air Quality Persists

Update 7:30 AM: Most areas received 0.01-0.05 inches of rain overnight! This will refresh the air some, but it will take much more rain to clear the smoke. Expect smoke through Wednesday.

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Due to a temperature inversion keeping near-surface air stagnant, smoke relief will take much longer than forecast models indicated. 

In addition, widespread rain is not likely until Thursday or Friday, as weak frontal systems will stay offshore.

The Air Quality Alert has been extended until 12 PM Thursday. You can view the alert below.

This alert gives an air quality "forecast" of sorts, and has some good tips for staying safe in the smoke.

Here is Puyallup's 6 PM AQI reading along with the AQI forecast for the South Sound.

248 is in the "very unhealthy" category. Last night, we peaked at a whopping 304 AQI, which was in the "hazardous" category. That AQI forecast isn't super motivating. It looks like AQI that is "unhealthy for sensitive groups" to "unhealthy" categories is likely until at least Thursday. These forecasts could always change. Here are those AQI categories.

You might be wondering why the smoke just isn't clearing out. This is due to poor air mixing...even though upper air smoke could clear, low level surface smoke will persist because of stagnant air near the surface. It will take more than a rain shower to clear this up. Air quality will slowly improve, but it will take a couple days longer than we previously thought. Why? Because the forecast models didn't account for the poor air mixing and stagnant low level smoke.

Here is Monday's satellite image. You see clouds on top of near-surface smoke in Western Washington. A trend that will continue.

However, improving AQI by Friday seems likely. By this time there will be a better chance of rain, along with the possibility of thunderstorms. Friday isn't the only chance of rain, as there is small chances of showers each day leading up to "showers likely" late Thursday and Friday. 

There is some good news, though. Total rain through Monday, September 21st is forecast to be 0.64-1.28 inches. 

I will keep you posted on how much rain we get, and when. Right now (Monday night) it looks likely that we will have a widespread chance of rain by Friday, with a drying trend by Sunday.

For information on 100 mph Hurricane Sally, that is threatening the LA/MS/AL/FL Gulf Coast, see the link below.

https://www.nhc.noaa.gov/graphics_at4.shtml?start#contents

Hang in there! Relief is coming but not as soon as previously thought.