Update: Temperature Swings, Local Flooding, Snow Still Possible

Update 8:35 PM:

Snow or a rain/snow mix is falling across much of the South/Central Sound. Snow will taper through the next hour, with a cold night (32-36 degrees) ahead. Be safe and enjoy the beauty of snowflakes falling!

Update 7:35 PM:

It is snowing across Puget Sound!! Some snow is accumulating on grassy, non-road surfaces, with some isolated spots with snowy roads. Expect snow to continue until 8:30-9:30 PM. Enjoy the snow!!

I took the photo above on my deck around 7:00 PM!

Update 6:40 PM:

It is snowing in Federal Way and Bonney Lake, along with many locations to the north. Conditions are conducive for snow for another couple hours, until roughly 9 PM. Don't expect accumulations on roads for the time being.

Comment below with pictures/videos/reports!!

5:00 PM Update Below. Hourly updates will be above this.

As of 5 PM, temperatures are beginning to cool around the South Sound. Temperatures spiked to 55-63 degrees ahead of the warm front midday, accompanied by winds gusting 30-45 mph. The 5 PM NWS temperature observations show roughly where the cold air is located.

Temperatures are cooling fast, with a drop from 50 to 43 in about 30 minutes!

In addition to cooling temperatures, heavy rain has moved through the Puget Sound area in the past couple hours, with urban flooding occurring in parts of the region.

The 4 PM radar image showed a heavy band of rain with more heavy rain behind it.

This brought strong winds, very heavy rain, and localized flooding. Most of the South/Central Sound received 0.2-0.5 inches of rain in 3 hours.

Now for snow...cold air is moving in behind the cold front. With the presence of moisture, there is a chance of snow until roughly 9 PM. 

A rain/snow mix is the most likely scenario, with all snow possible with heavier precipitation and temperatures below 33-35 degrees. Most places recording mix or snow have temperatures below 37 degrees, so there’s a “benchmark” of sorts.

Radar at 5:30 PM shows a rain/snow line just north of Seattle. This has been moving south with the colder temperatures.

A rain/snow mix is possible in the few miles south of the rain/snow line. The best shot at snow is through 9 PM. After that, moisture will be moving out of the area.

I’ll try to put hourly updates at the top of this blog post. Stay tuned!!