Earliest snow in 33 years brushes Seattle; More possible overnight

Ronald Reagan was still in his first term as president. Stevie Wonder was topping the charts. And in Seattle, it snowed on Halloween.

The year was 1984.

That’s how far back in time you have to go to find an earlier instance of snowfall than yesterday’s surprise, which unleashed a steady stream of big, fluffy flakes over downtown Seattle—during the heart of the day to boot. The snow, which dusted lawns, cars and many a starstruck onlooker, kept daytime temperatures in the 30s—a far cry from the normal 50-degree readings we’re used to seeing at this time of year. (The actual high temperature for the day of 43 was set at 4 a.m., before the winds shifted dramatically to the north.)

At Sea-Tac Airport, where the city’s weather records are kept, a trace of snow was officially recorded—the earliest in 33 years. Had the white stuff amounted to a tenth of an inch or more, it would have made for the earliest measurable snow in Seattle since November of 1973.

Believe it or not, we have another shot at the mark tomorrow.

An area of low pressure over B.C. is forecast to dive south off our coastline overnight before coming onshore near the mouth of the Columbia River. The low is then predicted to shuffle eastward to near Chehalis, drawing cold Canadian air out of the Fraser River Valley as it does so. The result? Moisture from the low heading north, while arctic air spills southward—a near-perfect trajectory for snowfall across the Seattle metro.

The one caveat? Because it’s only early November, the cold air coming from Canada isn’t really *that* cold. So, tomorrow morning’s snow is likely to fall with temperatures hovering a few degrees above freezing—meaning snow should only stick to grass and dirt in most spots. Snow is not expected to accumulate on roads below 500 feet.

That said, here’s our general timeline and forecast:

  • This afternoon/early evening: On-and-off rain showers.  Rain/snow mix likely in heavier showers north of Seattle. Temperatures: 36-42 degrees.
  • Mid-to-late evening (7 pm-11 pm): Persistent light rain or rain/snow mix. Temperatures: 35-40 degrees
  • Overnight (11 pm-5 am): Rain/snow mix, changing to light snow. Temperatures: 33-37 degrees.
  • Sunday morning (5 am-11 am): Light to moderate wet snow, with accumulations in the grass/dirt of 1-2 inches, mostly above 300 feet. Temperatures: 32-36 degrees.

Enjoy the early-season treat—and don’t forget to share your weather photos and videos with us on Twitter or Facebook!