I will have an update at noon.... Some light snow showers are over western WA right now....
The most powerful high-resolution meteorological tools are now available for the snow event tomorrow night. Parts of the lowlands will get snow--up to several inches in places.
But it won't last.
And the situation tomorrow is not a good one for accumulating lowland snow in our region.
The Golden Rule of Snow
Snowfall is NOT snow depth.
This is going to be very important for the upcoming event. And this subtlety is often missing from the analyses of some amateur weather websites.
A key issue is the temperature of the ground and particularly roadway surfaces. Below are this morning's values from the city of Seattle's Snowwatch website, with the temperatures in the boxes showing the roadway surface temperature. Most are in the upper 30s to near 40F.
First, here is the forecast for the 3-h total precipitation ending at 4 PM Tuesday. Snow around the Olympics Peninsula, but heavy rain offshore and light rain over the interior.