Chance of Rain & Thunderstorms, Smoke Improvement In Sight!

Thursday makes it 7 days of "unhealthy" air quality. That is a very long time to have degraded AQI in Western Washington. Thankfully, a chance of rain and shifting winds will bring improvement to the smoke situation through Friday and into the weekend, along with rain and a chance of thunderstorms.

Let's break it down. Here is the Air Quality Alert, which has been extended until 10 AM Saturday.

It is likely that we will see some kind of impact from smoke through Saturday. Below is Puyallup's 6 PM air quality reading and forecast.

We are out of the "unhealthy" category!!! We are now in "unhealthy for sensitive groups," an improvement from yesterday! From late Thursday through Friday, we will likely hover in the 110 (unhealthy for sensitive groups) to 160 (unhealthy) range. However, air quality is improving! This is a good trend that is likely to continue through the next few days, as the AQI forecast indicates.

Now let's look at the current near surface smoke situation. Here is 11 PM Thursday.

Smoke is still thick in the interior of Western Washington late Thursday night. This will keep air quality in the "unhealthy for sensitive groups" category through midday Friday.

However...look at 11 PM Friday. Wow!!

Barely any smoke in Western Washington! That is a sight that many of us in Western Washington will be happy to see! I still expect there to be some lingering smoke through Saturday morning, but there will be big improvement by the end of the weekend! As indicated in the AQI forecast earlier, air quality in the "good" category is likely by Sunday!

This is because winds that have been blowing from the south (bringing smoke) will shift to coming from the southwest (bringing cool and clean marine air). This will be a very welcome change!

Now...let's talk rain and thunderstorms. The NWS Storm Prediction Center (SPC) shows a risk of general thunderstorms over Western Washington, with a marginal and slight risk of severe thunderstorms over the Oregon Cascades, parts of the Willamette Valley, and South Central Washington. There is even a 2% tornado threat over the Oregon Cascades...that's very rare for the PNW...but I don't expect a big chance that tornadoes will form.

At 9 PM Thursday, thunderstorms have been moving up the Oregon Coast Range, with no impact to our area yet.

However, instability does exist over Western Washington and that will remain in place through Friday. There is a chance of thunderstorms in our area through the day Friday.

Let's take a look at the precipitation forecast from the UW WRF model. It looks likely that the best chance for rain in the Puget Sound area is from 5 AM Friday-5 AM Saturday.

The forecast shows that during this time, South/Central Puget Sound gets 0.15-0.50 inches of rain. Some places will get more, some will get less. Rain will end by Saturday, and dry but cool conditions, with highs 65-72 degrees will prevail from Saturday through the middle of next week.

By the second half of next week, a more widespread rain event is likely. Current forecasts indicate that our area will receive 0.50-3.0 inches of rain through the next 10 days. Stay tuned.

Bottom line: Smoke improvement is slowly beginning, 0.15-0.50 inches of rain is likely through Saturday, and there is a chance of thunderstorms through Friday.