The Snow Band Approaches

The snowband advertised by the models is now approaching the coast and should swing inland during the next few hours (indicated by the arrow on the infrared satellite image at 9 PM). The low pressure system, indicated by the circular swirl of clouds, is west of southern Vancouver Island.

Really cold air (single digits to teens) is pushing toward Bellingham, with gusts to around 45 mph.  Brutal stuff.  And temperatures in most of the rest of western Washington are in the low to mid-30s.

The latest WRF model run swings the precipitation band through overnight, dropping about 2 inches around central Puget Sound (see 24 hr snowfall ending 4 PM Monday).  Much more north of the Olympics and in some locations of SW WA.

The NOAA HRRR model has a similar solution:

I can't stress enough that snowfall is not the same as snow accumulation.  After a warmer than normal January, soil and roadway temperatures are relatively warm.  You can see that by looking at the latest air and roadway temperatures from the City of Seattle's SnowWatch website (see below).
Even with near-surface air temperatures at freezing or below, the road temperatures (in the boxes) are well above freezing.  With the help of some deicing solutions (spread by SDOT and WSDOT), I suspect the main roadways will be fine tomorrow morning as long as the air temperatures remain above the mid to lower 20s...and they will.   

from Cliff Mass Weather and Climate Blog http://bit.ly/2RCFbcD