Snow In The Seattle Area? Here's How Much We Might Get

SEATTLE, WA - Puget Sound's snow-free winter so far might come to an end on Sunday. A cold air mass from Canada and moisture coming from the south could collide on Sunday, dropping perhaps as much as an inch in the Seattle area.

Most forecasts are at this point predicting some kind of snowfall beginning Sunday night and lasting into Monday morning. The usually-reliable National Weather Service shows a 60 percent chance of snow, but "little to no accumulation" in Seattle.

Higher snow totals are likely for the convergence zone, which will probably form somewhere north of Marysville, according to Seattle Weather Blog forecaster Justin Shaw.

Here's what Shaw sees for the weekend:

"On Sunday, cold air will begin invading Western Washington as low pressure dives south off our coastline, pulling down arctic air from the Fraser River Valley in the process. As chilly air surges into the state from the north, it's likely to collide with damper air blowing up from the south.

"Where this confrontation occurs — likely somewhere between Bellingham and Marysville — a few inches of snow could fall Sunday night in a convergence zone of sorts. Further south, in the greater Seattle metro area, an inch of snow is possible, mainly early Monday morning, as northerly winds sweep into the region overnight," Shaw said.

There are a few caveats, Shaw says: the arctic air coming from Canada is pretty dry, so areas farther from the convergence zone will see less snow. There's also the chance of a snow shadow in the Seattle-Tacoma area — essentially, the Olympics will block precipitation.

"That said, this is definitely the most promising set-up for snow we've seen in the Seattle area this winter. Fingers crossed!" Shaw said.

Here's the forecast for the whole weekend for the Seattle area from the NWS:

Friday: Rain. Steady temperature around 48. South southeast wind 9 to 13 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

Friday Night: Showers likely, mainly before 11pm. Cloudy, with a low around 42. South wind 8 to 11 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Saturday: A 30 percent chance of showers. Mostly cloudy, with a high near 49. East wind 5 to 10 mph becoming north northwest in the afternoon.

Saturday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 39.

Sunday: A chance of rain showers before 5pm, then rain and snow showers likely. Mostly cloudy, with a high near 45. Chance of precipitation is 60%. Little or no snow accumulation expected.

Sunday Night: Rain and snow showers likely before 11pm, then a chance of snow showers. Mostly cloudy, with a low around 32.

Patch file photo