Snow in Seattle is an infrequent event. The Pacific Ocean and Rocky Mountains combine to moderate winter temperatures in the Puget Sound basin, occluding the production of snow, and when it does snow, it usually melts within a day; thus, the community long ago decided not to spend resources on snow removal equipment that would sit idle for years at a time. Once every score of years, though, the snow does pile up, which, given our terrain and lack of snow plows, creates a good excuse to stay home, wear fuzzy slippers, and drink cocoa. This week we had around five inches of snow fall overnight Sunday into Monday, and that snow remained frozen in place. Beginning yesterday afternoon, another series of fronts added more than a half foot to the total, and the mounting snow has created bedlam.

Radar captured how heavily the snow fell overnight last night: 7.9 inches at the National Weather Service observation station since yesterday,¹ which is an inch more than the average annual snowfall. One poor soul has perished in the cold. The state governor has declared a state of emergency(PDF) and modified the declaration today to waive rules limiting the daily work hours of motor carriers and drivers of commercial motor vehicles either collecting and delivering essential food and emergency supplies to grocery stores for retail resale to the public or delivering bulk propane fuel supplies to bulk propane distributers (grocery store shelves have been stripped clean). Winds up to 70 MPH are blowing across the north part of the state from the direction of the Fraser River, and the wind chill is below zero in places where the temperature may only occasionally explore freezing. Flights at Seattle–Tacoma International Airport are rarely canceled due to snow: according to FlightAware, 251 flights were canceled yesterday at Sea–Tac.

It stopped snowing late this morning, and the skies cleared this afternoon. My wife and I went for a walk around the neighborhood and encountered a couple traveling on cross‐country skies, which was not unlike encountering someone wearing a bikini here in the winter — extraordinary. The forecast calls for snow again tomorrow and an increasing possibility of up to another foot of snow on Tuesday. I think that will be enough snow.

Update February 11, 2019
New snow last night made this the snowiest February on record for Seattle, with 14.1 inches total for the month. It has been snowing again this afternoon, although warm air is moving into the area from the southwest, which is forecast to change the snow to rain overnight. This screen capture of the wind circulating counterclockwise at the surface around a low pressure system offshore today from Vancounter Island neatly illustrates how that warm air is being delivered overhead from off of the Pacific Ocean.

Update March 1, 2019

February will end up being the 3rd coldest at SeaTac since records started in 1945 with an average temperature of 36.7. The coldest was 35.6 in 1956. It will also be the snowiest February on record with 20.2". The old February snow record was 13.1" in 1949. — NWS Seattle (@NWSSeattle) February 28, 2019