WeatherWatcher: Air Quality Alert, Rain finally in distant sight

 

Smoke filtered sun
Photo by Carl Dinse

The summer that keeps on giving and should have ended a month ago continues. We have had no measurable precipitation for the entire month of October thus far, and we are far above the average temperature for this time of year. 

There is an end in sight, though and much needed rains are appearing on the horizon. We must get through this weekend and next week first.

October temperatures compared to average in Shoreline (Echo Lake/North Ridge station)

An Air Quality Alert is in effect through the weekend. Offshore flow is expected to increase during the weekend, bringing us warmer and drier air and smoke from the Bolt Creek Fire. Winds in the mountains will be increasing from the east as well, which will fan the wildfires and increase their activity.

Forecast calls for sunny skies and areas of smoke. Temperatures Saturday are expected to be in the 70's and Sunday we could see temps near 80°F. Onshore flow (westerly winds) returns Sunday evening which will cool us back down and hopefully clear some of the smoke out.

Monday through Thursday next week is expected to have continued sunny skies with temperatures in the mid 60's to near 70°F. Not much of a change day to day until we get to around Friday. The jet stream begins to drop south, aiming the river of storms and cold fronts to our region.

Long range suggests we'll switch to more normal October weather overnight Friday and continue, as far as models can go. Accuracy is highly degraded though when going that far out in forecasting. One thing is for sure, we are heading into our third La Niña winter season in a row, which means more rain and colder than normal temperatures in general.

Winter season outlook: With the Pacific Decadal Oscillation (PDO) deep into a cold phase and a triple dip La Niña, we can expect this winter to be on the cold and rainier side of things, not unlike the past few winter seasons we've had. Usual frequency of storms is expected with probably at least one significant snow event. 

I do expect Shoreline and Lake Forest Park to be snowier than average again this winter. Keep in mind the official average annual snowfall for Seattle is around 4.6-6.3 inches. I expect we will see more than 6 inches of snow this winter through one or multiple events.

If the smoke doesn't get too unhealthy this is probably the last weekend to do outside stuff before the rains finally return. I'll be checking air quality on the Puget Sound Clean Air agency website to determine if it's safe to do any outdoor stuff this weekend. Summer is finally coming to an end.

For current weather conditions visit www.shorelineweather.com